Cohort Profile: The Tokyo Teen Cohort study (TTC)

Predictors of psychotic experiences among adolescents with obsessive-compulsive symptoms: A data-driven machine learning approach

Aim

Prediction of future psychosis in individuals with obsessive and compulsive (OC) symptoms is crucial for treatment choice, but only a few predictors have been revealed. Although OC symptoms and psychotic experiences (PEs) are common in adolescence, no studies have revealed the predictors of subsequent PEs in adolescents with OC symptoms. We aimed to explore the predictors for subsequent PEs among adolescents with OC symptoms, using a data-driven machine-learning approach on an adolescent cohort.

Methods

We used data from a cohort study on the general population of adolescents in Tokyo (n = 3171 at age 10). Data were collected at age 10, 12, 14, and 16. We focused on a subgroup of participants who had OC symptoms at age 12. Participants who had PEs at age 10 were excluded. A machine learning method was utilized to explore over 600 potential predictors at baseline, distinguishing between those who had an onset of PEs after age 14 (n = 45) and those who never had PEs (n = 99).

Results

The predicting model demonstrated a good performance (test area under the curve = 0.80 ± 0.05). Other than known risk factors for PEs, novel predictors of subsequent PEs among adolescents with OC symptoms included: lack of interaction with people of different ages, desire to be like their father in the future, and nonworking of primary caregiver when they were 5 years old. Not sharing their belongings readily with other children was a strong predictor of having no PEs.

Conclusion

Close-knit family bonds and limited social connections outside the family predict the later PEs among adolescents with OC symptoms.

Trajectories of depressive symptoms among young people in London, UK, and Tokyo, Japan: a longitudinal cross-cohort study

BACKGROUND

Research suggests gender inequalities in adolescent mental health are context dependent and might be preventable through social and structural change. However, variations in the size of gender inequalities in mental health across diverse cultural contexts could be due to incomparable measurement. We aimed to compare a measurement of mental health among young people in Tokyo, Japan, and London, UK, and test the hypothesis that gender inequalities in depressive symptom trajectories are larger in London than in Tokyo.

METHODS

For this longitudinal cross-cohort study, we extracted responses to the 13-item Short Mood and Feelings Questionnaire (SMFQ) by young people who participated in three consecutive waves of the Tokyo Teen Cohort (TTC) and the London-based Resilience, Ethnicity and Adolescent Mental Health (REACH) cohorts. We used multigroup and longitudinal confirmatory factor analysis to examine measurement invariance of the SMFQ by cohort, gender, and age. Latent growth curve models were used to estimate and compare mean trajectories of SMFQ from ages 11-16 years among boys and girls, overall, and in each cohort.

FINDINGS

7100 young people from TTC and REACH (3587 boys [50·5%] and 3513 girls [49·5%]) were included in the analysis. With the TTC and REACH cohorts combined, we found very strong evidence of differences in SMFQ between boys and girls, with a mean starting level of 0·71 points (95% CI 0·42-0·95) higher and mean rate of change of 0·73 points (95% CI 0·62-0·82) higher in girls versus boys. Among the 4287 participants in REACH (2097 [48·9%] boys and 2190 [51·1%] girls), a difference in SMFQ was evident between boys and girls at age 11-12 years (difference in mean intercepts: 0·75 [95% CI 0·25-1·25]). Among the 2813 participants in TCC (1490 boys [53·0%] and 1323 girls [47·0%]), differences in SMFQ between boys and girls emerged at a later age, between ages 11 years and 14 years, during which SMFQ decreased among boys and increased among girls (mean difference in slopes 0·52 [95% CI 0·40 to 0·65]). The difference in SMFQ between boys and girls widened year-on-year in both cohorts; by age 16 years, the difference in SMFQ between boys and girls in REACH (mean difference in slopes 0·98 [95% CI 0·77 to 1·20]) was around twice as large as in TTC (0·52 [0·40 to 0·65]). The annual rate of increase in SMFQ among girls in REACH (1·1 [95% CI 0·9-1·3]) was around four times greater than among girls in TTC (0·3 [0·2-0·4]). We found little evidence to suggest these differences in gender inequalities were due to incomparable measurement.

INTERPRETATION

Gender inequalities in emotional health among young people are context dependent and might be preventable through social and structural change.

FUNDING

Japanese Society for the Promotion of Science, UK Economic and Social Research Council, and European Research Council.

TRANSLATION

For the Japanese translation of the abstract see Supplementary Materials section.

Protective role of school climate for impacts of COVID-19 on depressive symptoms and psychotic experiences among adolescents: a population-based cohort study

BACKGROUND

Schools are central places for adolescent social lives, which is a major factor greatly affecting adolescent mental health; school climate (i.e. quality of the school social environments) can be a proximal social determinant for adolescent mental health. Supportive school environments may serve as a protective factor during crises like COVID-19, which disrupt social lives and worsen adolescent mental health. This is the first study examining whether the pandemic effects differed based on the levels of school climate on depressive symptoms (DS) and psychotic experiences (PEs) among adolescents.

METHODS

School climate (score range: 0-28), DS (0-26), and PEs (0-5) were self-reported in a population-based cohort (Tokyo Teen Cohort; N = 3171) at four timepoints (10y, 12y, 14y, and 16y) before and during COVID-19. COVID-19 occurred midway through the 16y survey, allowing us to examine its impact and interaction effect with school climate while accounting for within-person changes over time using mixed-effects models.

RESULTS

Significant interaction effects were found on DS (unstandardized coefficient [B] = -0.166, 95% confidence interval [CI] -0.225 to -0.107) and PEs (B = -0.020, 95% CI -0.028 to -0.012). The pandemic effects were not significant for adolescents with high school climate scores (around the 80th percentile or higher), although the pandemic significantly worsened these outcomes among the overall sample.

CONCLUSIONS

The negative mental health effects of the pandemic were significantly mitigated among adolescents experiencing a supportive school climate. A positive school climate can protect adolescent mental health during challenging social conditions, such as pandemics.

Association of Problematic Internet Use With Psychotic Experiences and Depression in Adolescents: A Cohort Study

BACKGROUND AND HYPOTHESIS

Problematic internet use (PIU) is prevalent among adolescents. Past research suggested cross-sectional associations between PIU and psychotic experiences, but little information is available on the longitudinal association. We hypothesized that PIU in adolescence may be longitudinally associated with psychotic experiences, adjusting for confounders.

STUDY DESIGN

We analyzed a random sample of adolescents in the Tokyo Teen Cohort to examine how PIU at ages 10 (2012-2015), 12 (2014-2017), and 16 (2019-2021) was associated with mental health issues at age 16. PIU was evaluated by the modified Compulsive Internet Use Scale, psychotic experiences by the Adolescent Psychotic-like Symptom Screener, and depression by the Short Mood and Feelings Questionnaire. We also examined the mediating role of social withdrawal.

STUDY RESULTS

We analyzed 3171 adolescents; 151 reported psychotic experiences and 327 reported depression at age 16. Compared with the lowest tertile PIU group, the highest tertile PIU group at age 12 showed an increased adjusted risk of psychotic experiences (RD 3.3%, 95% CI 2.9%-3.7%; RR 1.65, 95% CI 1.55-1.73) and depression (RD 5.9%, 95% CI 5.5%-6.3%; RR 1.61, 95% CI 1.55-1.68) at age 16. PIU at age 16 showed analogous results, while PIU at age 10 suggested a smaller impact. Social withdrawal mediated 9.4%-29.0% of the association between PIU and psychotic experiences.

CONCLUSIONS

PIU is longitudinally associated with psychotic experiences and depression in adolescents. Further longitudinal and intervention studies are warranted to provide robust public health implications and foster a safer digital future.

Investigating the Differential Impact of Short- and Long-Term Informal Caregiving on Mental Health Across Adolescence: Data From the Tokyo Teen Cohort

PURPOSE

Young caregivers experience, on average, poorer mental health outcomes than non-caregiving young people. However, it is unknown to what extent these effects differ with age, or among short-term versus long-term caregivers. Using repeated assessment of young caregiving across multiple waves of a prospective adolescent cohort study, we conducted repeated cross-sectional analyses of caregiver status and contemporaneous depressive symptoms, self-harm, and suicidality in early to middle adolescence.

METHODS

Four waves of questionnaire data from a large, longitudinal population-based cohort study (Tokyo Teen Cohort) were analyzed. Caregiver status was collected from participants aged 10, 12, 14, and 16 years. Mental health outcomes assessed were depressive symptoms, self-harm and suicidal feelings. Logistic regression analyses were conducted assessing effects of a) young caregiver status and b) new, long-term, and ex-caregiver 2-year categorizations on mental health outcomes at 12, 14, and 16 years, both unadjusted and adjusted for potential confounders (sex, low income, single-parent household, and parental distress).

RESULTS

Depressive symptoms were elevated among long-term caregivers at 14 years (unadjusted odds ratio (uOR): 3.11 [1.33-7.27], adjusted odds ratio (aOR): 2.49 [1.03-5.99]). Borderline associations between long-term caregiving and self-harm (uOR: 3.14 [1.06-9.35], aOR: 2.51 [0.82-7.63]) and suicidal feelings (uOR: 2.49 [0.98-6.34], aOR: 2.06 [0.80-5.33]) were detected at 16 years. No associations were found at age 12 years in primary analyses; sensitivity analyses indicated possible increased depressive symptoms.

DISCUSSION

Young caregivers with long-term caregiving roles are at the greatest risk for negative mental health outcomes, with effects concentrated in later adolescence. These findings highlight urgent need for early identification and practical and psychological support for young people shouldering caregiving burdens.

The Dynamic Interplay Between Puberty and Structural Brain Development as a Predictor of Mental Health Difficulties in Adolescence: A Systematic Review

Puberty is a time of intense reorganization of brain structure and a high-risk period for the onset of mental health problems, with variations in pubertal timing and tempo intensifying this risk. We conducted 2 systematic reviews of articles published up to February 1, 2024, focusing on 1) the role of brain structure in the relationship between puberty and mental health, and 2) precision psychiatry research evaluating the utility of puberty in making individualized predictions of mental health outcomes in young people. The first review provides inconsistent evidence about whether and how pubertal and psychopathological processes may interact in relation to brain development. While most studies found an association between early puberty and mental health difficulties in adolescents, evidence on whether brain structure mediates this relationship is mixed. The pituitary gland was found to be associated with mental health status during this time, possibly through its central role in regulating puberty and its function in the hypothalamic-pituitary-gonadal and hypothalamic-pituitary-adrenal axes. In the second review, the design of studies that have explored puberty in predictive models did not allow for a quantification of its predictive power. However, when puberty was evaluated through physically observable characteristics rather than hormonal measures, it was more commonly identified as a predictor of depression, anxiety, and suicidality in adolescence. Social processes may be more relevant than biological ones to the link between puberty and mental health problems and represent an important target for educational strategies.

Psychotic experiences and dissociation in adolescents: Within-person analysis in the Tokyo teen cohort

Although many cross-sectional studies showed that psychotic experiences (PEs) and dissociation were closely related, the longitudinal association between them remains unknown. Therefore, the aim of the current study was to examine the longitudinal association of these two symptoms throughout adolescence, under the hypothesis that these two symptoms are bidirectionally associated. Data were obtained from a population-based cohort, the Tokyo Teen Cohort study (TTC; N = 3171). PEs and dissociation were assessed at 10, 12, 14, and 16 years of age. PEs were assessed using a total score from five-item self-report questionnaires derived from the Diagnostic Interview Schedule for Children (DISC-C). Dissociation was assessed using subscale scores of the Child Behavior Checklist (CBCL) completed by primary caregivers. We examined the longitudinal relationship between PEs and dissociation using the random intercept cross-lagged panel model (RI-CLPM). The within-person component of the RI-CLPM revealed no significant cross-lagged effect of dissociation on PEs at any time point. On the other hand, there was a significant (p < 0.05) association between PEs at age 14 and dissociation at age 16 (β = 0.106, 95 % CI 0.047-0.165). The between-person component revealed a significant time-invariant relationship between the two symptoms (β = 0.324, 95 % CI 0.239-0.410). The longitudinal relationship between PEs and dissociation was limited at the within-person level, whereas the between-person correlation was significant. The only significant longitudinal pathway was from PEs to dissociation, suggesting that PEs may be a predictor of dissociation in mid-adolescence.

Adolescent psychotic experiences before and during the COVID-19 pandemic: a prospective cohort study

BACKGROUND

Understanding the etiology of psychosis is essential to the development of preventive interventions. The COVID-19 pandemic provides a rare natural experiment that can expand our understanding of the role of social factors in the trajectories and etiology of psychosis across adolescence, particularly in Tokyo where the prevalence of actual COVID-19 infection remained low. We hypothesized that the likelihood of self-reporting psychotic experiences (PEs) would increase following the onset of the COVID-19 pandemic.

METHODS

The Tokyo Teen Cohort (TTC) is a prospective cohort study of adolescents in the general population of the Tokyo metropolitan area, followed from age 10 to 16 years. We used multi-level linear regression models to test the associations between the phase of the COVID-19 pandemic and self-reported PEs.

RESULTS

Among 1935 adolescents included in the analysis, a rapid increase in PEs occurred at the onset of the COVID-19 pandemic, following approximately 6 years of steady decline across prior waves. This association was more pronounced for boys compared to girls. This increase became more pronounced as the pandemic moved into later phases, defined based on contemporaneous sociopolitical changes in Tokyo (i.e. changes to school closure, social distancing guidelines, and the state of emergency status).

CONCLUSIONS

The steady decline in PEs across adolescence was halted and reversed concurrent with the COVID-19 pandemic onset, despite very low rates of COVID-19 infection. This implicates COVID-19 related socioenvironmental factors as contributory etiological factors in the development of PEs in this adolescent cohort.

Parent-Child Associations in COVID-19-Related Preventive Behaviors and Efficacy Expectations: A One-Year Longitudinal Survey

PURPOSE

It is necessary to identify the variables that explain the variance in preventive behaviors against COVID-19 to increase adolescents' engagement in these behaviors. We focused on efficacy expectations of preventive behaviors and their associations within families. This study examined the associations between efficacy expectations and preventive behaviors, and between adolescents and their parents in terms of efficacy expectations and preventive behaviors.

METHODS

A cross-lagged panel model was employed to analyze 281 parent-child pairs consisting of 245 children (118 girls, mean age = 17.4 years), 277 mothers (median age = 49.3 years), and 211 fathers (median age = 51.5 years). Participants completed the Prevention of COVID-19 Infection Scale at baseline (October 2020 to April 2021) and one-year follow-up to assess efficacy expectations and preventive behaviors for sanitization, contact, and hoarding factors.

RESULTS

Efficacy expectations of preventive behaviors at baseline were positively associated with preventive behaviors at one-year follow-up regarding the sanitization and contact factors. Additionally, for parents, efficacy expectations of preventive behaviors at baseline were positively associated with subsequent preventive behaviors regarding the hoarding factor. Parental efficacy expectation scores for contact at baseline were positively associated with their children's scores at one-year follow-up.

DISCUSSION

The findings highlight the association between parental efficacy expectations at an initial time point and adolescents' efficacy expectations at one-year follow-up toward COVID-19 preventive measures, particularly contact-related behaviors. These insights can inform public health interventions targeting individual expectations and parental involvement to promote effective preventive practices during future health crises.

Sex Differences in Adolescent Depression Trajectory Before and Into the Second Year of COVID-19 Pandemic

OBJECTIVE

Evidence on the impact of the COVID-19 pandemic on adolescent mental health is mixed and does not disentangle natural age-related changes. We compared depressive symptoms among 16-year-olds surveyed, at a fourth wave, before or during the pandemic, while accounting for expected trajectories of within-person change based on 3 prior waves.

METHOD

In this longitudinal cohort of 3,171 adolescents in Tokyo, Japan, adolescents were grouped based on their age 16 survey timing: pre-pandemic (February 2019 to February 2020) and during-pandemic (March 2020 to September 2021). Depressive symptoms were self-reported using the Short Mood and Feelings Questionnaire. Mixed-effect models were fitted to assess group differences while controlling for previous trends. Variations by sex, household income, and pandemic phase (early, late first-year, and second-year) were examined.

RESULTS

Of 2,034 eligible adolescents, 960 (455 girls) were assessed before and 1,074 (515 girls) during the pandemic. Overall, depressive symptoms increased by 0.80 points (95% CI 0.28-1.31, 0.15 SD of the population average). This increase varied by sex and pandemic phase. For boys the increase emerged in the late first-year phase and enlarged in the second-year phase (mean difference from pre-pandemic: 1.69, 0.14-3.24), whereas for girls it decreased in the early school-closure phase (mean difference: -1.98, -3.54 to -0.41) and returned to the pre-pandemic level thereafter, with no additional increases during the pandemic.

CONCLUSION

Into the second year of the COVID-19 pandemic, depressive symptoms of 16-year-olds worsened above the expected age-related change only in boys. Continuous monitoring and preventive approaches for adolescents at the population level are warranted.

DIVERSITY & INCLUSION STATEMENT

We worked to ensure that the study questionnaires were prepared in an inclusive way. We worked to ensure sex and gender balance in the recruitment of human participants. One or more of the authors of this paper self-identifies as a member of one or more historically underrepresented racial and/or ethnic groups in science. We actively worked to promote sex and gender balance in our author group. The author list of this paper includes contributors from the location and/or community where the research was conducted who participated in the data collection, design, analysis, and/or interpretation of the work.

Macronutrient intake is associated with intelligence and neural development in adolescents

Introduction

Macronutrient intake can be one of the most influential factors in cognitive and neural development in adolescents. Adolescence is a specific period of cognitive and neural development, and nutritional effects during this period could be life-long. Therefore, understanding the effects of macronutrient intake on cognitive and neural development in adolescents is crucially important. We thus examined the association across macronutrient intake, intelligence, and neural development using population-based cohort data.

Methods

We conducted two studies. In study 1, we included a total of 1,734 participants (boys, 907, age [mean ± standard deviation] 171.9 ± 3.44 months; range 163.0-186.0 months) from the Tokyo TEEN Cohort (TTC) to examine the association between macronutrient intake and intelligence quotient (IQ). In study 2, we included a total of 63 participants (boys, 38, age 174.4 ± 7.7 months; range 160.7-191.6 months) to investigate the effect of nutrition intake on neural development using graph theory analysis for resting-state functional magnetic resonance imaging (rs-fMRI) derived from a subset of the TTC.

Results

TTC data revealed that a higher IQ was associated in boys with increased protein intake (β = 0.068, p = 0.031), and in girls, with reduced carbohydrate intake (β = -0.076, p = 0.024). Graph theory analysis for rs-fMRI at approximately age 12 has shown that impaired local efficiency in the left inferior frontal gyrus was associated with higher carbohydrate and fat intake ([x, y, z] = [-51, 23, 8], pFDR-corrected = 0.00018 and 0.02290, respectively), whereas increased betweenness centrality in the left middle temporal gyrus was associated with higher carbohydrate, fat, and protein intake ([x, y, z] = [-61, -43, -13], pFDR-corrected = 0.0027, 0.0029, and 0.00075, respectively). Moreover, we identified a significant moderating effect of fat and protein intake on the relationship between change in betweenness centrality over a 2-year measurement gap in the left middle temporal gyrus and intelligence (β = 12.41, p = 0.0457; β = 12.12, p = 0.0401, respectively).

Conclusion

Our study showed the association between macronutrient intake and neural development related to intelligence in early adolescents. Appropriate nutritional intake would be a key factor for healthy cognitive and neural development.

Longitudinal trajectories of anterior cingulate glutamate and subclinical psychotic experiences in early adolescence: the impact of bullying victimization

Previous studies reported decreased glutamate levels in the anterior cingulate cortex (ACC) in non-treatment-resistant schizophrenia and first-episode psychosis. However, ACC glutamatergic changes in subjects at high-risk for psychosis, and the effects of commonly experienced environmental emotional/social stressors on glutamatergic function in adolescents remain unclear. In this study, adolescents recruited from the general population underwent proton magnetic resonance spectroscopy (MRS) of the pregenual ACC using a 3-Tesla scanner. We explored longitudinal data on the association of combined glutamate-glutamine (Glx) levels, measured by MRS, with subclinical psychotic experiences. Moreover, we investigated associations of bullying victimization, a risk factor for subclinical psychotic experiences, and help-seeking intentions, a coping strategy against stressors including bullying victimization, with Glx levels. Finally, path analyses were conducted to explore multivariate associations. For a contrast analysis, gamma-aminobutyric acid plus macromolecule (GABA+) levels were also analyzed. Negative associations were found between Glx levels and subclinical psychotic experiences at both Times 1 (n = 219, mean age 11.5 y) and 2 (n = 211, mean age 13.6 y), as well as for over-time changes (n = 157, mean interval 2.0 y). Moreover, effects of bullying victimization and bullying victimization × help-seeking intention interaction effects on Glx levels were found (n = 156). Specifically, bullying victimization decreased Glx levels, whereas help-seeking intention increased Glx levels only in bullied adolescents. Finally, associations among bullying victimization, help-seeking intention, Glx levels, and subclinical psychotic experiences were revealed. GABA+ analysis revealed no significant results. This is the first adolescent study to reveal longitudinal trajectories of the association between glutamatergic function and subclinical psychotic experiences and to elucidate the effect of commonly experienced environmental emotional/social stressors on glutamatergic function. Our findings may deepen the understanding of how environmental emotional/social stressors induce impaired glutamatergic neurotransmission that could be the underpinning of liability for psychotic experiences in early adolescence.

Uncovering associations between gender nonconformity, psychosocial factors, and mental health in adolescents: a birth cohort study

BACKGROUND

Little information is available on the association between gender nonconformity during adolescence and subsequent mental health. While the distress related to gender nonconformity may be socially produced rather than attributed to individual-level factors, further research is needed to better understand the role of psychosocial factors in this context.

METHOD

We analyzed data from the Tokyo Teen Cohort, obtained through random sampling of adolescents born between 2002 and 2004. We used inverse probability weighting to examine the association of gender nonconformity at ages 12 and 14 as a time-varying variable with subsequent mental health at age 16, while accounting for time-fixed and time-varying confounders. Furthermore, we used a weighting approach to investigate the mediating role of modifiable psychosocial factors in this association, addressing exposure-mediator and mediator-mediator interactions.

RESULTS

A total of 3171 participants were analyzed. Persistent gender nonconforming behavior at ages 12 and 14 was associated with subsequent depression (β = 2.02, 95% confidence interval [CI] 0.85 to 3.19) and psychotic experiences (β = 0.33, 95% CI 0.14 to 0.52) at age 16. The results remained robust in sensitivity analyses. Approximately 30% of the association between gender nonconformity and depression was consistently mediated by a set of psychosocial factors, namely loneliness, bullying victimization, and relationships with mother, father, and friends.

CONCLUSIONS

Persistent gender nonconformity during adolescence is associated with subsequent mental health. Psychosocial factors play a vital mediating role in this association, highlighting the essential need for social intervention and change to reduce stigmatization and ameliorate mental health challenges.

Hippocampal Structures Among Japanese Adolescents Before and After the COVID-19 Pandemic

Importance

Few studies have used a large-sample, longitudinal, population-based cohort study to examine whether the COVID-19 pandemic as a global major life event is associated with structural plasticity of the adolescent hippocampus.

Objective

To examine whether Japan's first state of emergency (SoE) during the COVID-19 pandemic was associated with alterations in the macrostructures and microstructures of the hippocampus during its development.

Design, Setting, and Participants

The population-neuroscience Tokyo TEEN Cohort study is a prospective cohort study with 4 consecutive waves in Tokyo, Japan. Due to the SoE, data collection was suspended between March 27, 2020, and July 30, 2020. Analyzed data, comprising 1149 brain structural scans obtained from 479 participants, of whom 336 participants had undergone 2 or more scans, were collected between October 2013 and November 2021. Data were analyzed from August 2022 to December 2023.

Exposures

Japan's first SoE (April 7 to May 25, 2020).

Main Outcomes and Measures

Hippocampal volume, 12 hippocampal subfield volumes, and 7 microstructural measures of the hippocampus.

Results

A total of 1060 brain scans from 459 participants (214 female participants [47%]) including 246 participants from wave 1 (median [IQR] age, 11.3 [11.1-11.7] years), 358 from wave 2 (median [IQR] age, 13.8 [13.3-14.5] years), 304 from wave 3 (median [IQR] age, 15.9 [15.4-16.5] years), and 152 from wave 4 (median [IQR] age, 17.9 [17.5-18.4] years) were included in the final main analysis. The generalized additive mixed model showed a significant associations of the SoE with the mean hippocampal volume (β = 102.19; 95% CI, 0.61-203.77; P = .049). The generalized linear mixed models showed the main associations of the SoE with hippocampal subfield volume (granule cell and molecular layer of the dentate gyrus: β = 18.19; 95% CI, 2.97-33.41; uncorrected P = .02; CA4: β = 12.75; 95% CI, 0.38-25.12; uncorrected P = .04; hippocampus-amygdala transition area: β = 5.67; 95% CI, 1.18-10.17; uncorrected P = .01), and fractional anisotropy (β = 0.03; 95% CI, 0.00-0.06; uncorrected P = .04).

Conclusions and Relevance

After the first SoE, a volumetric increase in the hippocampus and trend increase in 3 subfield volumes and microstructural integration of the hippocampus were observed, suggesting that the transient plasticity of the adolescent hippocampus was affected by a major life event along with the typical developmental trajectory.

Identify adolescents' help-seeking intention on suicide through self- and caregiver's assessments of psychobehavioral problems: deep clustering of the Tokyo TEEN Cohort study

Background

Psychopathological and behavioral problems in adolescence are highly comorbid, making their developmental trajectories complex and unclear partly due to technical limitations. We aimed to classify these trajectories using deep learning and identify predictors of cluster membership.

Methods

We conducted a population-based cohort study on 3171 adolescents from three Tokyo municipalities, with 2344 pairs of adolescents and caregivers participating at all four timepoints (ages 10, 12, 14, and 16) from 2012 to 2021. Adolescent psychopathological and behavioral problems were assessed by using self-report questionnaires. Both adolescents and caregivers assessed depression/anxiety and psychotic-like experiences. Caregivers assessed obsession/compulsion, dissociation, sociality problem, hyperactivity/inattention, conduct problem, somatic symptom, and withdrawal. Adolescents assessed desire for slimness, self-harm, and suicidal ideation. These trajectories were clustered with variational deep embedding with recurrence, and predictors were explored using multinomial logistic regression.

Findings

Five clusters were identified: unaffected (60.5%), minimal problems; internalizing (16.2%), persistent or worsening internalizing problems; discrepant (9.9%), subjective problems overlooked by caregivers; externalizing (9.6%), persistent externalizing problems; and severe (3.9%), chronic severe problems across symptoms. Stronger autistic traits and experience of bullying victimization commonly predicted the four "affected" clusters. The discrepant cluster, showing the highest risks for self-harm and suicidal ideation, was predicted by avoiding help-seeking for depression. The severe cluster predictors included maternal smoking during pregnancy, not bullying others, caregiver's psychological distress, and adolescent's dissatisfaction with family.

Interpretation

Approximately 40% of adolescents were classified as "affected" clusters. Proactive societal attention is warranted toward adolescents in the discrepant cluster whose suicidality is overlooked and who have difficulty seeking help.

Funding

Japan Ministry of Health, Labor and Welfare, Japan Agency for Medical Research and Development, and Japan Science and Technology Agency.

The longitudinal relationship between dissociative symptoms and self-harm in adolescents: a population-based cohort study

Previous studies have reported that dissociative symptoms (DIS) are associated with self-harm (SH) in adolescents. However, most of these studies were cross-sectional, which limits the understanding of their theoretical relationship. We aimed to investigate the longitudinal relationship between DIS and SH in the general adolescent population. We used data from the Tokyo Teen Cohort study (N = 3007). DIS and SH were assessed at times 1 and 2 (T1 and T2) (12 years of age and 14 years of age, respectively). DIS were assessed using the parent-report Child Behavior Checklist (CBCL), and severe dissociative symptoms (SDIS) were defined as a score above the top 10th percentile. The experience of SH within 1 year was assessed by a self-report questionnaire. The longitudinal relationship between DIS and SH was examined using regression analyses. Using logistic regression analyses, we further investigated the risk for SH at T2 due to persistent SDIS and vice versa. DIS at T1 tended to predict SH at T2 (odds ratio (OR) 1.11, 95% CI 0.99 to 1.25, p = 0.08), while SH at T1 did not predict DIS at T2 (B = - 0.03, 95% CI - 0.26 to 0.20, p = 0.81). Compared with adolescents without SDIS, those with persistent SDIS had an increased risk of SH at T2 (OR 2.61, 95% CI 1.28 to 5.33, p = 0.01). DIS tended to predict future SH, but SH did not predict future DIS. DIS may be a target to prevent SH in adolescents. Intensive attention should be given to adolescents with SDIS due to their increased risk of SH.

Suicidal Thoughts and Trajectories of Psychopathological and Behavioral Symptoms in Adolescence

Importance

The suicidal risk of psychopathology in adolescence is suggested to differ based on its longitudinal trajectory, but the comorbidity of these symptom trajectories has not been well examined. This study comprehensively clustered trajectories of multiple psychopathological and behavioral symptoms and examined their associations with suicidal thoughts in adolescence.

Objective

To determine which categories and trajectories of psychopathological and behavioral symptoms are associated with suicidal thoughts in adolescence, accounting for comorbid symptoms.

Design, Setting, and Participants

This population-based cohort study in Japan used data from the Tokyo Teen Cohort (TTC) study, which was established in 2012 and is currently ongoing. Data from 3 waves of surveys conducted at ages 10, 12, and 16 years from October 2012 to September 2021 were used. Of the adolescents in the cohort, participants with at least 2 evaluations of psychopathological and behavioral symptoms were included. Data were analyzed from December 2022 to March 2023.

Exposure

Latent class growth analysis was used to cluster the trajectory of each psychopathological and behavioral symptom.

Main Outcomes and Measures

The associations between symptom trajectories and suicidal thoughts at age 16 were examined. Suicidal thoughts were assessed using a self-report questionnaire. Psychopathological and behavioral symptoms were assessed using the 8 subscale scores of the caregiver-report Child Behavior Checklist.

Results

This study included 2780 adolescents (1306 female participants [47.0%]). Of the 1920 adolescents with data on suicidal thoughts, 158 (8.2%) had suicidal thoughts. The median (IQR) age was 10.2 (10.0-10.3) years at the first evaluation, 11.9 (11.8-12.1) years at the second evaluation, and 16.3 (16.1-16.5) years at the last evaluation. The clustering pattern of trajectories varied depending on symptom categories. After adjusting for each symptom trajectory and confounders, adolescents with persistent high withdrawn symptoms (odds ratio [OR], 1.88; 95% CI, 1.10-3.21) and those with increasing somatic symptoms (OR, 1.97; 95% CI, 1.16-3.34) had a significantly higher risk of suicidal thoughts than adolescents without these symptoms. There was no interaction between these symptom trajectories and the risk of suicidal thoughts.

Conclusions and Relevance

This cohort study found that persistent withdrawn symptoms and increasing somatic symptoms during early to midadolescence were associated with an increased risk of suicidal thoughts in midadolescence, even after accounting for comorbid symptoms and confounders. Attention should be paid to the suicidal risk associated with these symptoms, particularly when they persist or increase in the longitudinal follow-up.

Longitudinal Relationships Between Help-Seeking Intentions and Depressive Symptoms in Adolescents

PURPOSE

Cross-sectional studies have shown an association between lower help-seeking intentions and greater depressive symptoms among adolescents. However, no longitudinal study has examined the direction of this association. The current study investigated whether help-seeking intentions and depressive symptoms are reciprocally associated at the within-person (individual) level during early to mid-adolescence.

METHODS

Longitudinal data on help-seeking intentions and depressive symptoms in adolescents were obtained from a population-based birth cohort study (Tokyo Teen Cohort; N = 3,171) at four time points (10y, 12y, 14y, and 16y). A random intercept cross-lagged panel model was used to evaluate the within-person prospective associations between help-seeking intentions and depressive symptoms.

RESULTS

At the within-person level, significant associations were consistently observed between antecedent greater depressive symptoms and subsequent lower help-seeking intentions across all time points (10y-12y: standardized regression coefficient (β) = -0.12, p < .001; 12y-14y: β = -0.07, p < .05; and 14y-16y: β = -0.09, p < .01). Meanwhile, significant within-person associations were partly observed between antecedent lower help-seeking intentions and subsequent greater depressive symptoms from 10y to 12y (β = -0.07, p < .05) and from 14y to 16y (β = -0.12, p < .001). These prospective associations were almost the same when adjusted for the number of potential confidants as a time-varying confounder.

DISCUSSION

Adolescents with worsening depressive symptoms may become increasingly reluctant to seek help over time. Proactive early recognition and intervention with support from parents, teachers, and other individuals may facilitate the management of depression in adolescents.

Within-Person Variability Score-Based Causal Inference: A Two-Step Estimation for Joint Effects of Time-Varying Treatments

Behavioral science researchers have shown strong interest in disaggregating within-person relations from between-person differences (stable traits) using longitudinal data. In this paper, we propose a method of within-person variability score-based causal inference for estimating joint effects of time-varying continuous treatments by controlling for stable traits of persons. After explaining the assumed data-generating process and providing formal definitions of stable trait factors, within-person variability scores, and joint effects of time-varying treatments at the within-person level, we introduce the proposed method, which consists of a two-step analysis. Within-person variability scores for each person, which are disaggregated from stable traits of that person, are first calculated using weights based on a best linear correlation preserving predictor through structural equation modeling (SEM). Causal parameters are then estimated via a potential outcome approach, either marginal structural models (MSMs) or structural nested mean models (SNMMs), using calculated within-person variability scores. Unlike the approach that relies entirely on SEM, the present method does not assume linearity for observed time-varying confounders at the within-person level. We emphasize the use of SNMMs with G-estimation because of its property of being doubly robust to model misspecifications in how observed time-varying confounders are functionally related to treatments/predictors and outcomes at the within-person level. Through simulation, we show that the proposed method can recover causal parameters well and that causal estimates might be severely biased if one does not properly account for stable traits. An empirical application using data regarding sleep habits and mental health status from the Tokyo Teen Cohort study is also provided.

Longitudinal change in mismatch negativity (MMN) but not in gamma-band auditory steady-state response (ASSR) is associated with psychological difficulties in adolescence

Adolescence is a critical period for psychological difficulties. Auditory mismatch negativity (MMN) and gamma-band auditory steady-state response (ASSR) are representative electrophysiological indices that mature during adolescence. However, the longitudinal association between MMN/ASSR and psychological difficulties among adolescents remains unclear. We measured MMN amplitude for duration and frequency changes and ASSR twice in a subsample (n = 67, mean age 13.4 and 16.1 years, respectively) from a large-scale population-based cohort. No significant longitudinal changes were observed in any of the electroencephalography indices. Changes in SDQ-TD were significantly associated with changes in duration MMN, but not frequency MMN and ASSR. Furthermore, the subgroup with higher SDQ-TD at follow-up showed a significant duration MMN decrease over time, whereas the subgroup with lower SDQ-TD did not. The results of our population neuroscience study suggest that insufficient changes in electroencephalography indices may have been because of the short follow-up period or non-monotonic change during adolescence, and indicated that the longitudinal association with psychological difficulties was specific to the duration MMN. These findings provide new insights that electrophysiological change may underlie the development of psychosocial difficulties emerging in adolescence.

Association between menopause and suicidal ideation in mothers of adolescents: A longitudinal study using data from a population-based cohort

BACKGROUND

Midlife suicide among women has attracted increasing research attention. This study aimed to investigate the longitudinal association between menopause and suicidal ideation among middle-aged women.

METHODS

Our data were derived from the Tokyo Teen Cohort, a population-based survey of early adolescents (N = 3171) and their primary caregivers (typically, mothers) in Japan. A total of 2944 mothers (baseline mean age = 44.0 years) were included in the analysis. The baseline assessment in this study was performed at second-wave survey from July 2014 to January 2017. A follow-up assessment was conducted at fourth-wave survey from February 2019 to September 2021. Suicidal ideation at baseline and follow-up was assessed using the Suicidal Ideation subscale of the 28-item General Health Questionnaire. Menopausal stage was classified based on self-report at fourth-wave survey.

RESULTS

Participants who started the perimenopausal stage after baseline were significantly more likely to have suicidal ideation at follow-up than those who did not have experienced menopausal transition yet. Participants with greater social support were less likely to report suicidal ideation at follow-up, even after adjusting for baseline suicidal ideation.

LIMITATIONS

This study was based on self-report regarding menopausal stage and only included mothers of adolescents from Japan. An exact length of time from the onset to the presence of suicidal ideation was unavailable.

CONCLUSIONS

Women who have experienced the onset of menopausal transition presented an increased risk of suicidal ideation. Psychosocial interventions to increase social support may be beneficial in preventing mental health inequalities during menopausal transitions.

"World-Informed" Neuroscience for Diversity and Inclusion: An Organizational Change in Cognitive Sciences

By nature, humans are "tojisha (participating subjects/player-witnesses)" who encounter an unpredictable real world. An important characteristic of the relationship between the individual brain and the world is that it creates a loop of interaction and mutual formation. However, cognitive sciences have traditionally been based on a model that treats the world as a given constant. We propose incorporating the interaction loop into this model to create "world-informed neuroscience (WIN)". Based on co-productive research with people with minority characteristics that do not match the world, we hypothesize that the tojisha and the world interact in a two-dimensional way of rule-based and story-based. By defining the cognitive process of becoming tojisha in this way, it is possible to contribute to the various issues of the real world and diversity and inclusion through the integration of the humanities and sciences. The critical role of the brain dopamine system as a basis for brain-world interaction and the importance of research on urbanicity and adolescent development as examples of the application of WIN were discussed. The promotion of these studies will require bidirectional translation between human population science and animal cognitive neuroscience. We propose that the social model of disability should be incorporated into cognitive sciences, and that disability-informed innovation is needed to identify how social factors are involved in mismatches that are difficult to visualize. To promote WIN to ultimately contribute to a diverse and inclusive society, co-production of research from the initial stage of research design should be a baseline requirement.

Transmit Radiant Individuality to Offspring (TRIO) study: investigating intergenerational transmission effects on brain development

Intergenerational transmission is a crucial aspect of human development. Although prior studies have demonstrated the continuity of psychopathology and maladaptive upbringing environments between parents and offspring, the underlying neurobiological mechanisms remain unclear. We have begun a novel neuroimaging research project, the Transmit Radiant Individuality to Offspring (TRIO) study, which focuses on biological parent-offspring trios. The participants of the TRIO study were Japanese parent-offspring trios consisting of offspring aged 10-40 and their biological mother and father. Structural and functional brain images of all participants were acquired using magnetic resonance imaging (MRI). Saliva samples were collected for DNA analysis. We obtained psychosocial information, such as intelligence, mental health problems, personality traits, and experiences during the developmental period from each parent and offspring in the same manner as much as possible. By April 2023, we completed data acquisition from 174 trios consisting of fathers, mothers, and offspring. The target sample size was 310 trios. However, we plan to conduct genetic and epigenetic analyses, and the sample size is expected to be expanded further while developing this project into a multi-site collaborative study in the future. The TRIO study can challenge the elucidation of the mechanism of intergenerational transmission effects on human development by collecting diverse information from parents and offspring at the molecular, neural, and behavioral levels. Our study provides interdisciplinary insights into how individuals' lives are involved in the construction of the lives of their descendants in the subsequent generation.

Informal Caregiving in Adolescents from 10 to 16 Years Old: A Longitudinal Study Using Data from the Tokyo Teen Cohort

There is growing evidence of the impact of informal caregiving on adolescent mental health, and its role is often hidden unintentionally or intentionally, which may hamper early identification and support for young informal caregivers. However, the quantitative evidence regarding household factors relating to informal caregiving has mostly been based on cross-sectional findings. This study examines the longitudinal associations between household characteristics and the duration of informal caregiving in adolescents from 10 to 16 years of age. Child-household respondent pairs (n = 2331) from the Tokyo Teen Cohort in Japan were followed every 2 years from 10 to 16 years of age. Informal caregiving was assessed repeatedly based on the household respondent's survey responses. Persistent caregiving was defined as daily caregiving at two or more waves. There were 2.2% of children who gave daily care at two or more waves. Cross-sectional associations with daily informal caregiving at each wave were found with girls, low household income, and cohabiting with grandparents. A significant association with persistent caregiving was found only in cohabiting with grandparents at 10 years of age after adjusting for sex, number of siblings, single parent, and household income. Our longitudinal examination highlighted cohabiting with grandparents as a preceding factor for persistent caregiving. Identification and support for young informal caregivers should be integrated into social care service systems for older adults. The mechanism of persistent caregiving requires clarification.

Auditory Hallucinations and Self-Injurious Behavior in General Population Adolescents: Modeling Within-Person Effects in the Tokyo Teen Cohort

BACKGROUND AND HYPOTHESES

A wealth of evidence suggests that adolescent psychotic experiences (PEs), and especially auditory hallucinations (AHs), are associated with an increased risk for self-injurious behavior (SIB). However, the directionality and specificity of this association are not well understood, and there are no published studies investigating within-person effects over time. The present study aimed to test whether AHs and SIB prospectively increase reciprocal risk at the individual level during early-to-middle adolescence.

STUDY DESIGN

Three waves (12y, 14y, and 16y) of self-reported AHs and SIB data from a large Tokyo-based adolescent birth cohort (N = 2825) were used. Random Intercept Cross-Lagged Panel Model (RI-CLPM) analysis was conducted to test the within-person prospective associations between AHs and SIB.

STUDY RESULTS

At the within-person level, AHs were associated with subsequent SIB over the observation period (12y-14y: β = .118, P < .001; 14-16y: β = .086, P = .012). The reverse SIB->AHs relationship was non-significant at 12-14y (β = .047, P = .112) but emerged from 14y to 16y as the primary direction of influence (β = .243, P < .001). Incorporating depression as a time-varying covariate did not meaningfully alter model estimates.

CONCLUSIONS

A complex bi-directional pattern of relationships was observed between AHs and SIB over the measurement period, and these relationships were independent of depressive symptoms. Adolescent AHs may be both a predictor of later SIB and also a manifestation of SIB-induced psychological distress.

Urinary exosomal microRNAs as predictive biomarkers for persistent psychotic-like experiences

Psychotic-like experiences (PLEs) occur occasionally in adolescence and mostly disappear with increasing age. Their presence, if persistent, is considered a robust risk factor for subsequent psychiatric disorders. To date, only a few biological markers have been investigated for persistent PLE prediction. This study identified urinary exosomal microRNAs that can serve as predictive biomarkers for persistent PLEs. This study was part of a population-based biomarker subsample study of the Tokyo Teen Cohort Study. A total of 345 participants aged 13 (baseline) and 14 (follow-up) years underwent PLE assessments by experienced psychiatrists using semi-structured interviews. We defined remitted and persistent PLEs based on longitudinal profiles. We obtained urine at baseline and the expression levels of urinary exosomal miRNAs were compared between 15 individuals with persistent PLEs and 15 age- and sex-matched individuals with remitted PLEs. We constructed a logistic regression model to examine whether miRNA expression levels could predict persistent PLEs. We identified six significant differentially expressed microRNAs, namely hsa-miR-486-5p, hsa-miR-199a-3p, hsa-miR-144-5p, hsa-miR-451a, hsa-miR-143-3p, and hsa-miR-142-3p. The predictive model showed an area under the curve of 0.860 (95% confidence interval: 0.713-0.993) for five-fold cross-validation. We found a subset of urinary exosomal microRNAs that were differentially expressed in persistent PLEs and presented the likelihood that a microRNA-based statistical model could predict them with high accuracy. Therefore, urine exosomal miRNAs may serve as novel biomarkers for the risk of psychiatric disorders.

Attributes of auditory hallucinations that are associated with self-harm: A prospective cohort study

There is a well-documented epidemiological association between auditory hallucinations and self-harm in the general population. However, there has been limited research examining specific characteristics of auditory hallucinations (e.g., type, source, or context of voices) as correlates of self-harm. We used prospective data from the Tokyo Teen Cohort to explore whether characteristics of voices reported at age 14 were differentially associated with self-harm behaviors at ages 14 and 16. Among respondents with auditory hallucinations, respondents who experienced voices that "said something bad" about them or commented on their thoughts and actions were most likely to report concurrent self-harm, whereas positive or praising voices were protective. Negative voices continued to predict self-harm two years later, at age 16, even with adjustment for self-harm at age 14. The age of the voices, source of the voices, and context (e.g., falling asleep or while sick) was not associated with likelihood of reporting concurrent or subsequent self-harm behaviors. Assessing for negative voices in particular, rather than auditory hallucinations or psychotic experiences more broadly, may provide a more specific indicator of risk for self-harm among adolescents. The real-world utility of these epidemiological findings should be further examined in clinical settings.

Predictors of chronic loneliness during adolescence: a population-based cohort study

BACKGROUND

Adolescent loneliness is a growing public health issue owing to its adverse health impact. Although adolescent loneliness is common, its trajectories can show distinct patterns over time. However, there is limited knowledge regarding their determinants, particularly for chronic loneliness. We aimed to determine the predictors of loneliness trajectories across early-to-mid adolescence and examine their association with later suicidality.

METHODS

Data were collected from 3165 participants from the population-based Tokyo Teen Cohort. Participants reported their loneliness at 10, 12, 14, and 16 years. Loneliness trajectories were identified using latent class growth analysis. We examined the predictive role of bullying victimization and parental psychological distress at age 10 via a multinomial logistic regression. Sociodemographic and child-related factors (i.e., chronic health conditions and cognitive delay) were included as covariates. The association between the trajectories, self-harm, and suicidal ideation by age 16 was investigated using Poisson regression.

RESULTS

Four trajectories were identified: "consistently low" (2448, 77.3%), "moderate-decreasing" (185, 5.8%), "moderate-increasing" (508, 16.1%), and "consistently high" (24, 0.8%). Taking "consistently low" as a reference, experiences of bullying victimization predicted all the remaining trajectories [adjusted relative risk ratio 1.64, 95% confidence interval (CI) 1.18-2.28 for "moderate-decreasing," 1.88, 1.52-2.33 for "moderate-increasing," and 4.57, 1.97-10.59 for "consistently high"]. Parental psychological distress predicted the "moderate-increasing" (1.84, 1.25-2.71) and "consistently high" (5.07, 1.78-14.42) trajectories. The "consistently high" trajectory showed the greatest risk for self-harm and suicidal ideation (adjusted relative risk ratio 6.01, 95% CI 4.40-8.22; 2.48, 1.82-3.37, respectively); however, the "moderate-increasing" and "moderate-decreasing" trajectories were also at increased risk (moderate-increasing: 2.71, 2.23-3.30 for self-harm, 1.93, 1.69-2.19 for suicidal ideation; moderate-decreasing: 2.49, 1.91-3.26 for self-harm, 1.59, 1.33-1.91 for suicidal ideation).

CONCLUSIONS

Bullying victimization and parental psychological distress at age 10 were independent determinants of increased and chronic loneliness trajectories across early-to-mid adolescence. Compared with "consistently low," all other loneliness trajectories were associated with an increased risk of adolescent suicidality. Interventions targeting adolescent loneliness should include approaches to mitigate bullying and parental psychological distress. These strategies may help prevent adolescent suicidality.

Role of advanced glycation end products in the longitudinal association between muscular strength and psychotic symptoms among adolescents

Muscular strength, assessed by handgrip, is a risk indicator for psychiatric disorders, including psychosis. However, the biological mechanisms underlying this association remain unclear. Since advanced glycation end products (AGEs) play a key role in skeletal muscle underdevelopment and psychosis, we examined the role of AGEs in the longitudinal association between muscular strength and psychotic symptoms among adolescents. We first evaluated the direction of the relationship between handgrip strength and urine levels of pentosidine, a representative AGEs in a population-based birth cohort of 1,542 adolescents at ages 12 and 14. Then, we examined the role of AGEs in the longitudinal association between handgrip strength and thought problems (TP), as a psychotic symptom indicator, in a subsample of 256 adolescents at ages 13 and 14. An autoregressive cross-lagged model revealed that handgrip strength at age 12 negatively predicted pentosidine levels at age 14 (β = −0.20, p < 0.001), whereas pentosidine levels at age 12 did not predict handgrip strength at age 14 (β = 0.04, p = 0.062). Moreover, pentosidine levels had a significant indirect effect on the relationship between handgrip strength and TP (standard indirect effect = −0.051, p = 0.012), which remained significant after adjusting for gender and preceded TP and pentosidine levels. Thus, adolescents with low muscular strength are at a high risk of developing psychotic symptoms, which could be mediated by AGEs. Future studies need to investigate whether interventions focused on muscular strength prevent the accumulation of AGEs and thereby prevent the development of psychosis.

Maternal parenting stress from birth to 36 months, maternal depressive symptoms, and physical punishment to 10-year-old children: a population-based birth cohort study

PURPOSE

This study aimed to investigate the association between parenting stress, maternal depressive symptoms, and use of physical punishment when the child is 10 years old.

METHODS

Data from the Tokyo Early Adolescence Survey on early adolescents and primary caregivers (N = 4478) were used. Frequency of using physical punishment, level of depressive symptoms (Kessler Psychological Distress Scale 6), and maternal parenting stress experienced at 1, 3, 9, 18, and 36 months after birth were evaluated. Multiple linear and multinomial logistic regression analyses were conducted.

RESULTS

Mothers (1633) who provided information on parenting stress at all the five points were included for the analysis. After controlling for the child's age, sex, birth weight, maternal age, and annual household income, presence of maternal parenting stress at every time point, except at three months after birth, was significantly associated with an increased risk of using physical punishment with the 10-year-old. After adjusting for levels of depressive symptoms, significant associations were found between use of physical punishment and maternal parenting stress at 1 month (adjusted odds ratio [OR] 1.71, 95% confidence interval [Cl] 1.12-2.61) and 36 months (adjusted OR 1.70, 95% CI 1.10-2.61) after birth.

CONCLUSION

Maternal parenting stress experienced at 1 and 36 months after birth predicted use of physical punishment, even after adjusting for maternal depressive symptoms. Maternal support should, therefore, be provided to mothers to cope with parenting stress even three years after birth to prevent the use of physical punishment in early adolescence.

Young carers in Japan: Reliability and validity testing of the BBC/University of Nottingham young carers survey questionnaire and prevalence estimation in 5000 adolescents

Aim

Young carers (YCs) refer to children under the age of 18 who assume responsibilities that would normally be assumed by adults, such as caring for family members in need of care. In recent years, the concept of YCs has been expanding in Japan, and the government has been rapidly implementing strategies to support them. There is a need for a survey scale for YCs that uses standardized methods that can be compared internationally.

Method

The BBC/University of Nottingham Survey for estimating the prevalence of YCs and caring activities of United Kingdom adolescents was translated into Japanese, and its reliability and validity were tested with 313 adolescents. Moreover, the prevalence of YCs was estimated in a school-based survey among 5000 adolescents.

Results

The Young Carers Scale Japanese version (YCS-J) was acceptably reliable and valid. The original six-factor model for caring activity in the Multidimensional Assessment of Caring Activities Checklist for Young Carers (MACA-YC18) was supported by confirmatory factor analysis. The prevalence of YCs among 5000 adolescents in the Tokyo metropolitan area was estimated to be 7.4%, comparable to that reported in Western countries and in recent surveys in Japan using nonstandardized methods. YCs exhibited significantly higher scores for prosocial behavior and emotional symptoms than non-YCs.

Conclusions

The YCS-J, as an internationally comparable instrument, will be useful for understanding the actual situation of YCs in Japan, and to disseminate and implement support through cooperation among education, welfare, and healthcare sectors.

Sex-based differences in the longitudinal association between autistic traits and positive psychotic experiences in adolescents: A population-based cohort study

Previous reports have suggested a cross-sectional association between autistic traits and psychotic experiences (PEs) in adolescents. However, while both autistic traits and PEs show sex-related differences, no studies have directly assessed whether such differences exist in the longitudinal association between autistic traits and PEs. Using a population-based adolescent cohort sample (n = 3007), we tested whether the longitudinal association between autistic traits and positive PEs was affected by sex-based differences using regression analyses. Autistic traits were assessed at 12 years old (timepoint 1 [T1]), and PEs were assessed at 12 and 14 years old (T1 and T2). Subsequently, we tested whether subdomains of autistic traits (difficulties in social interaction, communication, imagination, attention to detail, and attention switching) were associated with subtypes of PEs (auditory hallucinations, visual hallucinations, and delusions) using structural equation modeling, after controlling for PEs at T1, socio-economic status, school performance and parents' psychiatric disorders. After controlling for PEs at T1, we did not find any associations between autistic traits at T1 and PEs at T2 in both sexes. There was no significant positive or negative association between all subdomains of autistic traits and subtypes of PEs in both sexes. Autistic traits do not seem to predict future PEs in general adolescents regardless of sex.

Effects of Trace Elements on Anthropometric Characteristics of Children: Cobalt and Childhood Body Mass Index

Objectives

There are many reports on the effects of trace elements on human anthropometric characteristics. Among these elements, cobalt has consistently shown an inverse relationship with obesity risk. In the present study, we aimed to investigate the relationship between urinary levels of trace elements, focusing on cobalt, and childhood obesity, as indicated by the body mass index (BMI) in early adolescents, focusing on the participants' gender.

Design

A cross-sectional study was conducted in the Tokyo Teen Cohort study. Based on urinary samples, we obtained the anthropometric characteristics (weight and height) and potential covariates associated with childhood BMI for 1542 children (mean age=12 years; 860 boys and 682 girls).

Methods

Concentrations of urinary cobalt and 17 other trace elements were measured using inductively coupled plasma-mass spectrometry or inductively coupled plasma-atomic emission spectrometry.

Results

Pearson's correlation coefficient revealed an inverse relationship between the log of cobalt concentrations in the urine and the BMI for the boys (r=-0.125, p<0.001) and girls (r=-0.082, p=0.033). Multivariate analysis, adjusted for various covariates, reconfirmed the correlation between urine cobalt and the childhood BMI, only in the boys (beta=-0.14, p<0.001).

Conclusions

Among the 18 elements measured in the children's urine, cobalt may exhibit sufficient potency to decrease the risk of childhood obesity, particularly in boys. Future studies are required to clearly determine the magnitude of the effect and the underlying mechanism(s).

Personalized values in life as point of interaction with the world: Developmental/neurobehavioral basis and implications for psychiatry

Behavioral neuroscience has dealt with short-term decision making but has not defined either daily or longer-term life actions. The individual brain interacts with the society/world, but where that point of action is and how it interacts has never been an explicit scientific question. Here, we redefine value as an intrapersonal driver of medium- and long-term life actions. Value has the following three aspects. The first is value as a driving force of action, a factor that commits people to take default-mode or intrinsic actions daily and longer term. It consists of value memories based on past experiences, and a sense of values, the source of choosing actions under uncertain circumstances. It is also a multilayered structure of unconscious/automatic and conscious/self-controlled. The second is personalized value, which focuses not only on the value of human beings in general, but on the aspect that is individualized and personalized, which is the foundation of diversity in society. Third, the value is developed through the life course. It is necessary to clarify how values are personalized through the internalization of parent-child, peer, and social experiences through adolescence, a life stage almost neglected in neuroscience. This viewpoint describes the brain and the behavioral basis of adolescence in which the value and its personalization occur, and the importance of this personalized value as a point of interaction between the individual brain and the world. Then the significance of personalized values in psychiatry is discussed, and the concept of values-informed psychiatry is proposed.

Neighborhood Social Cohesion and Dementia-Related Stigma Among Mothers of Adolescents in the Pre- and Current COVID-19 Period: An Observational Study Using Population-Based Cohort Data

Background: Middle-aged adults may be the ideal target group for dementia-related stigma reduction interventions to encourage the utilization of services among those who may become family caregivers. Neighborhood social cohesion may diminish dementia-related stigma, particularly in terms of perceived public attitudes. The COVID-19 pandemic can further negatively impact perceived public stigma. Objective: To investigate the association between neighborhood social cohesion and dementia-related stigma during the pre- and current COVID-19 period. Methods: We employed a cross-sectional design using data from a large population-based cohort, the Tokyo Teen Cohort, in Japan. Overall, 2,469 mothers of 16-year-old adolescents self-completed a questionnaire comprising nine dementia-related stigma questions evaluating perceived public and personal attitudes. Neighborhood social cohesion was assessed using a five-item instrument. The participants were divided into two groups according to the time of assessment: prior to the pandemic’s onset (February 2019–March 2020) and during the pandemic (April 2020–July 2021). A multiple regression analysis of stigma was performed using neighborhood social cohesion as an independent variable, and caring experience, age, educational level, and working status as covariates. Results: Personal and perceived public stigma were significantly lower in participants who perceived greater neighborhood social cohesion. However, level of personal and perceived public stigma did not differ between pre- and during the pandemic period. Conclusion: Neighborhood social cohesion may be a modifiable factor for dementia-related stigma. A localized intervention to enhance social cohesion in the neighborhood community would promote the utilization of services among those who may become family caregivers.

Association between maternal perceived capacity in life and physical punishment of teenage children: a longitudinal analysis of a population-based cohort in Tokyo, Japan

OBJECTIVES

Perceived capacity denotes a subjective sense of having resources to cope with strains and hardships, and hence maternal perceived capacity may be protective against risk factors for child maltreatment. This study investigated the longitudinal association between maternal perceived capacity in life and child maltreatment.

DESIGN

This population-based longitudinal study used self-reported questionnaires from the Tokyo Teen Cohort study (TTC), a large community-based cohort study conducted in Japan between 2014 and 2019.

SETTING

Mother-child pairs were randomly recruited from the resident registries of three municipalities in Tokyo, Japan.

METHODS

A total of 2515 mothers participated. Mothers' perceived capacity in life was evaluated using the self-reported TTC wave 2 survey when their children were 12 years old. Mothers rated the extent to which they had capacity in terms of time, finance, physical well-being, mental well-being and life in general. Physical punishment, which is linked to more severe childhood maltreatment, was assessed using a question about the use of physical punishment at the wave 3 survey when children were 14 years old.

RESULTS

After controlling for baseline covariates (including maternal social support, age, marital status, annual household income, educational attainment, child's age, gender, sibling and birth order, and behavioural difficulties), higher perceived capacity in finance (OR 0.95, 95% CI 0.90 to 0.99, p=0.026) and mental well-being (OR 0.93, 95% CI 0.88 to 0.98, p=0.005) were associated with less frequent use of physical punishment with 14-year-old children.

CONCLUSIONS

Maternal perceived capacity in finance and mental well-being may decrease the risk of frequent use of physical punishment at the 2-year follow-up. Child maltreatment prevention strategies should aim to empower mothers and promote their perceived capacity in financial management and mental health.

Bidirectional relationship of problematic Internet use with hyperactivity/inattention and depressive symptoms in adolescents: a population-based cohort study

Problematic Internet use (PIU), hyperactivity/inattention, and depressive symptoms are comorbid problems in adolescence, but the causal relationships among these issues are unclear. To assess the relationships among PIU, hyperactivity/inattention, and depressive symptoms in adolescents in the general population. This longitudinal cohort study used data from the Tokyo Teen Cohort study in Tokyo, Japan, for two years between October 2012 and January 2015. Of the 3171 pairs of children and parents, 3007 pairs continued to participate in the second wave of the Tokyo Teen Cohort study. A total of 3007 children were included in the analysis (mean [standard deviation] age, 9.7 [0.4] years; 1418 women [47.2%]. Cross-lagged panel analysis revealed that PIU at timepoint 1 was significantly associated with hyperactivity/inattention at timepoint 2 (β = 0.03; 95% confidence interval (CI) 0.01-0.06), and hyperactivity/inattention at timepoint 1 was also significantly associated with PIU at timepoint 2 (β = 0.07; 95% CI 0.04-0.10), even after adjustments were made for depressive symptoms. Furthermore, PIU at timepoint 1 was significantly associated with depressive symptoms at timepoint 2 (β = 0.05; 95% CI 0.01-0.12), and depressive symptoms at timepoint 1 were also significantly associated with PIU at timepoint 2 (β = 0.05; 95% CI 0.02-0.07), even after adjustments were made for hyperactivity/inattention. These results support the bidirectional relationships among PIU, hyperactivity/inattention, and depressive symptoms. PIU may be a target to improve hyperactivity/inattention and depressive symptoms in adolescents.

Association of Paternal Workplace and Community Social Capital With Paternal Postnatal Depression and Anxiety: A Prospective Study

OBJECTIVE

The aim of this study is to examine the association between workplace and community social capital and fathers' postpartum depression and anxiety at 3 months after delivery in Japan.

METHODS

Fathers who had babies delivered in two obstetric clinics in Tokyo, Japan were recruited to take part in the study (response rate = 76.2%). Participants completed questionnaires measuring workplace and community social capital, depression, and anxiety at 1 week and a follow-up at 3 months post-delivery (N = 398). Multiple linear regression analyses were performed with multiple imputation for missing data (at most, N = 60, 15.1%).

RESULTS

Community social capital was inversely associated with both depressive symptoms (β = -0.21, 95%CI = -0.33 to -0.08) and anxiety (β = -0.38, 95%CI = -0.66 to -0.11) at 3 months, after adjusting for covariates. No association was found between workplace social capital and depressive symptoms and anxiety.

CONCLUSION

Paternal community social capital, but not workplace social capital, was shown to be a preventive factor for paternal depression and anxiety up to 3 months post-delivery. To prevent paternal mental health problems during the postpartum period, an intervention to promote paternal community, rather than workplace, social capital may be warranted.

The role of bullying victimization in the pathway between autistic traits and psychotic experiences in adolescence: Data from the Tokyo Teen Cohort study

Autistic traits are associated with psychotic experiences in adolescence; however, the mechanisms underlying this relationship are not well understood. Prior research indicates that bullying victimization increases the risk of psychotic experiences in general adolescent populations, and autistic youth are at higher risk of being bullied than their non-autistic peers. Using longitudinal data from general population adolescents aged 10-14 in the Tokyo Teen Cohort study, we tested the hypothesis that bullying is responsible for the association between autistic traits and psychotic experiences in adolescence. We identified an indirect effect (estimate = 0.033 [95% CIs: 0.014-0.057], p < 0.001) between autistic traits and psychotic experiences via bullying victimization, even after controlling for known confounders. Prevention of bullying victimization may be one avenue for reducing risk of psychosis among adolescents with high levels of autistic traits.

Self-Reported Maternal Parenting Stress From 9 m Is Longitudinally Associated With Child ADHD Symptoms at Age 12: Findings From a Population-Based Birth Cohort Study

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) develops in early childhood and carries lifelong impact, but early identification and intervention ensure optimal clinical outcomes. Prolonged or excessive parenting stress may be a response to infant behavioral differences antecedent to developmental disorders such as ADHD, and therefore represents a potentially valuable inclusion in routine early-life assessment. To investigate the feasibility of using routinely-collected self-reported maternal parenting stress as a risk marker for child ADHD, this study investigated the longitudinal association between maternal parenting stress from 1 to 36 months after childbirth and child ADHD in early adolescence.

METHODS

The sample comprised 2,638 children (1,253 girls) from the Tokyo Teen Cohort population-based birth cohort study. Mothers recorded parenting stress five times from 1 to 36 months following childbirth in the Maternal and Child Health Handbook, a tool used for routine early-life assessment in Japan. Nine years later, mothers evaluated their child's ADHD symptoms at 12 y using the hyperactivity/inattention subscale from the Strength and Difficulties Questionnaire.

RESULTS

Approximately 7.5% of parents reported that they had parenting stress at 36 m after childbirth. 6.2% of children were evaluated as above the cut-off for ADHD symptoms at 12 y. Parenting stress at 1 and 3-4 m was not associated with child ADHD symptoms at 12 y. However, child ADHD symptoms at 12 y was significantly associated with parenting stress at 9-10 m (unadjusted OR = 1.42, p =.047, 95% CI [1.00, 2/00]), 18 m (unadjusted OR = 1.57, p =.007, 95% CI [1.13, 2.19]) and 36 m (unadjusted OR = 1.67, p =.002, 95% CI [1.20, 2.31]). These associations remained after adjustment for child's sex, age in months and family income.

CONCLUSIONS

We identified associations between parenting stress at 9-10, 18 and 36 m after childbirth and child ADHD symptoms at 12 years old. Self-reported parenting stress data may have utility as an early indicator for ADHD risk. Participation in early-life health checks, assessment of parenting stress, and tailoring support to family needs should be promoted for early identification and intervention for ADHD.

Migration and Psychotic Experiences in the Tokyo Teen Cohort

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Associations between migration, ethnicity, and psychosis risk have not previously been researched in Japan.

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Children of migrants to Japan are at an elevated risk for psychotic experiences.

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The association between migration and psychosis does not appear to be present for children with an above-average IQ.

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Future studies should explore social exclusion as a potential mechanisms for the associations found in this study.

Background

Immigration has been shown to be associated with an increased risk for psychotic experiences, with similar effect sizes for first-generation and second-generation migration (i.e., children whose parents had migrated). However, this association varies by country, and by ethnic group at the within-country level, such that risk is greatest among migrants facing substantial social exclusion and disadvantage. This is the first study to our knowledge to examine migration as a potential risk factor for psychotic experiences in Japan.

Method

Using data from the Tokyo Teen Cohort (N=3052), we tested whether migrant status was associated with the lifetime prevalence of psychotic experiences at age 10.

Results

Only 2.2% of the sample (n=68) had at least one migrant parent. Psychotic experiences were more common among children with at least one migrant parent, odds ratio (95% CI) = 2.06(1.26–3.35). This association appeared to be driven primarily by visual hallucinations and thought broadcasting, and specific to children with lower IQ at age 10.

Discussion

The findings suggest that migrant status is associated with increased likelihood of psychotic experiences at age 10 in Tokyo, Japan. Future prospective research should explore social exclusion as a potential underlying mechanism and can further clarify the protective role of IQ and related factors.

Psychotic experiences predict subsequent loneliness among adolescents: A population-based birth cohort study

BACKGROUND

Cross-sectional studies have suggested that the occurrence of psychotic experiences is associated with loneliness in the general adolescent population. However, there has been a scarcity of prospective longitudinal studies on this topic.

METHODS

We investigated the longitudinal association between the presence of psychotic experiences and loneliness among adolescents using data from a population-based birth cohort study (Tokyo Teen Cohort; N = 3171). Psychotic experiences and loneliness were assessed at three timepoints with two-year intervals through early adolescence (age 10, 12, and 14).

RESULTS

After adjusting for demographic characteristics and potential confounding factors, linear regression analyses showed a significant longitudinal association between psychotic experiences and subsequent loneliness (for age 10 to 12: B = 0.041, 95% CI: 0.009-0.074, p = .013; for age 12 to 14: B = 0.061, 95% CI: 0.026-0.096, p = .001). The reverse association, between preceding loneliness and later psychotic experiences, was not significant (for age 10 to 12: B = 0.003, 95% CI: -0.052-0.057, p = .926; for age 12 to 14: B = -0.028, 95% CI: -0.088-0.032, p = .355).

DISCUSSION

Loneliness could be a sign of underlying psychotic experiences among adolescents but does not appear to be antecedent to these symptoms. Clinicians and teachers should assess for the presence of psychotic experiences in young adolescents who report loneliness. Future studies capturing PEs and loneliness at narrower time intervals, and including other potential mediators and confounders, may be insightful.

Being Praised for Prosocial Behaviors Longitudinally Reduces Depressive Symptoms in Early Adolescents: A Population-Based Cohort Study

BACKGROUND

Depression is highly prevalent and causes a heavy burden in adolescent life. Being praised for prosocial behavior might be a preventive factor because both being praised and prosocial behavior are protective against depression. Here, we investigated the longitudinal relationship between being praised for prosocial behavior and depressive symptoms in adolescents.

METHODS

In Tokyo Teen Cohort study (TTC), an ongoing prospective population-based cohort study, we collected 3,171 adolescents' data on self-reported experiences of being praised for prosocial behavior, depressive symptoms, and caregiver-evaluated prosocial behavior. Ten-year-old children were asked to freely describe answers to the question "What are you praised for?". Only children who clearly answered that they were praised for their prosocial behavior were designated the "prosocial praise group." The degree of depression at ages 10 and 12 was measured with the Short Mood and Feelings Questionnaire (SMFQ), a self-report questionnaire about depression. Objective prosocial behavior of the 10 year-old children was assessed by the Strength and Difficulty Questionnaire (SDQ). Multiple linear regression analysis was performed using the SMFQ score at age 12 as the objective variable and being praised for prosocial behavior as the main explanatory variable, and the SMFQ score at age 10 and the objective prosocial behavior at age 10 were included as confounders.

RESULTS

Depressive symptoms (SMFQ scores) in the "prosocial praise group" were significantly lower than those in the other group both at age 10 (4.3 ± 4.4 vs. 4.9 ± 4.6, p < 0.001) and at age (3.4 ± 4.2 vs. 4.0 ± 4.6, p < 0.01). In the single regression analysis, the children who reported being praised for prosocial behavior at age 10 had significantly lower depressive symptoms at age 12 (partial regression variable: -0.57, 95% confidence interval (CI) [-0.96, -0.17]). This association remained significant after adjusting for confounders, including baseline depressive symptoms (partial regression variable: -0.44, 95% CI [-0.80, -0.08]). Prosocial behavior alone was not associated with depressive symptoms.

CONCLUSIONS

Being praised for prosocial behavior rather than objective prosocial behavior at 10 years of age predicted lower depressive symptoms 2 years later. Praise for adolescents' prosocial behavior can be encouraged to prevent depression.

Children with special health care needs and mothers' anxiety/depression: Findings from the Tokyo Teen Cohort study

AIM

Children with special health care needs (CSHCN) are those who require more care for their physical, developmental, or emotional differences than their typically developing peers. Among a wide range of burdens that caregivers of CSHCN experience, the mental burden of caregivers is still not well investigated. This study aimed at examining the relationship between caring for CSHCN and mothers' anxiety/depression.

METHODS

This study used data from the Tokyo Early Adolescence Survey, a population-based cross-sectional survey. Using screening questionnaires, we evaluated the prevalence of CSHCN and identified their primary caregivers. Focusing on mothers as caregivers, we analyzed the relationship between having CSHCN and mothers' anxiety/depression, and between the severity of children's condition and mothers' anxiety/depression. We further determined what mediates these relationships using path analyses.

RESULTS

Among 4003 participants, we identified 502 CSHCN (12.5%), and 93% of responding caregivers were mothers. We found that mothers with CSHCN were significantly more anxious/depressed than those without CSHCN, which was closely related to the severity of children's condition. The mediation effect of social support on the relation between CSHCN and mothers' anxiety/depression was statistically significant.

CONCLUSION

Mothers of CSHCN were more anxious/depressed than other mothers in this study. Social support was indicated to have a significant mediating effect on the relationship between CSHCN and mothers' anxiety/depression. Our results suggest that considering ways to offer social support may effectively relieve the mental stress experienced by mothers of CSHCN.

Birth order and prosociality in the early adolescent brain

Birth order is a crucial environmental factor for child development. For example, later-born children are relatively unlikely to feel secure due to sibling competition or diluted parental resources. The positive effect of being earlier-born on cognitive intelligence is well-established. However, whether birth order is linked to social behavior remains controversial, and the neural correlates of birth order effects in adolescence when social cognition develops remain unknown. Here, we explored the birth order effect on prosociality using a large-scale population-based adolescent cohort. Next, since the amygdala is a key region for sociality and environmental stress, we examined amygdala substrates of the association between birth order and prosociality using a subset neuroimaging cohort. We found enhanced prosociality in later-born adolescents (N = 3160), and observed the mediating role of larger amygdala volume (N = 208) and amygdala-prefrontal functional connectivity with sex-selective effects (N = 183). We found that birth order, a non-genetic environmental factor, affects adolescent social development via different neural substrates. Our findings may indicate the later-born people’s adaptive survival strategy in stressful environments.

Lower help-seeking intentions mediate subsequent depressive symptoms among adolescents with high autistic traits: a population-based cohort study

Adolescents with high autistic traits are at increased risk of depression. Despite the importance of seeking help for early intervention, evidence on help-seeking intentions amongst this population is scarce. Using a population-based cohort in Japan, we examined adolescents' help-seeking intentions and preferences by the level of autistic traits and tested its mediating role on the association between high autistic traits and depressive symptoms. At age 12, we measured parent-rated autistic traits using the short version of the Autism Spectrum Quotient and classified the adolescents into two groups (≥ 6 as AQhigh, < 6 as AQlow); help-seeking intentions and preferences were assessed through a depression vignette. At age 14, depressive symptoms were self-rated using the Short Mood and Feelings Questionnaire. Hypothesised associations between autistic traits and help-seeking intentions or depressive symptoms were tested applying multivariable regression modelling, while mediation was tested with structural equation modelling. Of the 2505 adolescent participants, 200 (8%) were classified as AQhigh. In both groups, the main source of help-seeking was their family; however, 40% of the AQhigh group reported having no help-seeking intentions compared to 27% in the AQlow. The AQhigh group was at increased risk of not having help-seeking intentions (OR 1.84, 95% CI 1.35-2.50) and higher depressive symptoms (b coefficient 1.06, 0.33-1.79). Help-seeking intentions mediated 18% of the association mentioned above. Interventions to promote help-seeking intentions among adolescents with high autistic traits could reduce their subsequent depressive symptoms. Ideally, such interventions should be provided prior to adolescence and with the involvement of their parents.

Fingertip advanced glycation end products and psychotic symptoms among adolescents

Case control studies have suggested that advanced glycation end products play a key role in the pathophysiology of chronic schizophrenia. However, the longitudinal association between advanced glycation end products and psychotic symptoms among drug-naïve adolescents remains unclear. This study examined whether advanced glycation end products could predict the trajectory of psychotic symptoms in drug-naive adolescents using data from prospective population-based biomarker subsample study of the Tokyo Teen Cohort. A total of 277 community-dwelling adolescents aged 13 years without antipsychotic medication were analyzed. Fingertip advanced glycation end products were measured in adolescents using noninvasive technology that can be used quickly. The trajectory of psychotic symptoms in a 12-month follow-up was assessed by experienced psychiatrists using a semi-structured interview. Of the 277 participants, 13 (4.7%) experienced persistent psychotic symptoms (psychotic symptoms at baseline and follow-up), 65 (23.5%) experienced transient psychotic symptoms (psychotic symptoms at baseline or follow-up), and 199 (71.8%) did not have psychotic symptoms. Multinomial logistic regression analysis adjusted for age and sex revealed that baseline fingertip advanced glycation end products might predict the risk of persistent psychotic symptoms (odds ratio = 1.68; 95% confidence interval, 1.05-2.69; P = 0.03). Altogether, fingertip advanced glycation end products potentially predicted the trajectory of psychotic symptoms among drug-naive adolescents, which indicated its involvement in the pathophysiology of early psychosis. Further studies are required to identify strategies to reduce adolescent advanced glycation end products, which may contribute to preventing the onset of psychosis.

Intergenerational transmission of the patterns of functional and structural brain networks

There is clear evidence of intergenerational transmission of life values, cognitive traits, psychiatric disorders, and even aspects of daily decision making. To investigate biological substrates of this phenomenon, the brain has received increasing attention as a measurable biomarker and potential target for intervention. However, no previous study has quantitatively and comprehensively investigated the effects of intergenerational transmission on functional and structural brain networks. Here, by employing an unusually large cohort dataset (N = 84 parent-child dyads; 45 sons, 39 daughters, 81 mothers, and 3 fathers), we show that patterns of functional and structural brain networks are preserved over a generation. We also demonstrate that several demographic factors and behavioral/physiological phenotypes have a relationship with brain similarity. Collectively, our results provide a comprehensive picture of neurobiological substrates of intergenerational transmission and demonstrate the usability of our dataset for investigating the neurobiological substrates of intergenerational transmission.

Dietary Restraint Related to Body Weight Maintenance and Neural Processing in Value-Coding Areas in Adolescents

BACKGROUND

There is an alarming increase in the obesity prevalence among children in an environment of increasing availability of preprocessed high-calorie foods. However, some people maintain a healthy weight even in such obesogenic environments. This difference in body weight management could be attributed to individual differences in dietary restraint; however, its underlying neurocognitive mechanisms in adolescents remain unclear.

OBJECTIVES

This study aimed to elucidate these neurocognitive mechanisms in adolescents by examining the relationships between dietary restraint and the food-related value-coding region located in the ventromedial prefrontal cortex (vmPFC).

METHODS

The association between dietary restraint and BMI was tested using a multilinear regression analysis in a large early adolescent cohort (n = 2554; age, 12.2 ± 0.3 years; BMI, 17.9 ± 2.5 kg/m2; 1354 boys). Further, an fMRI experiment was designed to assess the association between the vmPFC response to food images and dietary restraint in 30 adolescents (age, 17.6 ± 1.9 years; BMI, 20.7 ± 2.2 kg/m2; 13 boys). Additionally, using 54 individuals from the cohort (age, 14.5 ± 0.6 years; BMI, 18.8 ± 2.6 kg/m2; 31 boys), we assessed the association between dietary restraint and intrinsic vmPFC-related functional connectivity.

RESULTS

In the cohort, adolescents with increased dietary restraint showed a lower BMI (β = -0.38; P < 0.001; B = -0.06; SE = 0.003). The fMRI results showed a decreased vmPFC response to high-calorie food were correlated with greater dietary restraint. Moreover, there was an association of attenuated intrinsic vmPFC-related functional connectivity in the superior and middle frontal gyrus and the middle temporal gyrus with greater dietary restraint.

CONCLUSIONS

Our findings suggest that dietary restraint in adolescents could be a preventive factor for weight gain; its effect involves modulating the vmPFC, which is associated with food value coding.

Brain/MINDS beyond human brain MRI project: A protocol for multi-level harmonization across brain disorders throughout the lifespan

Psychiatric and neurological disorders are afflictions of the brain that can affect individuals throughout their lifespan. Many brain magnetic resonance imaging (MRI) studies have been conducted; however, imaging-based biomarkers are not yet well established for diagnostic and therapeutic use. This article describes an outline of the planned study, the Brain/MINDS Beyond human brain MRI project (BMB-HBM, FY2018 ~ FY2023), which aims to establish clinically-relevant imaging biomarkers with multi-site harmonization by collecting data from healthy traveling subjects (TS) at 13 research sites. Collection of data in psychiatric and neurological disorders across the lifespan is also scheduled at 13 sites, whereas designing measurement procedures, developing and analyzing neuroimaging protocols, and databasing are done at three research sites. A high-quality scanning protocol, Harmonization Protocol (HARP), was established for five high-quality 3 T scanners to obtain multimodal brain images including T1 and T2-weighted, resting-state and task functional and diffusion-weighted MRI. Data are preprocessed and analyzed using approaches developed by the Human Connectome Project. Preliminary results in 30 TS demonstrated cortical thickness, myelin, functional connectivity measures are comparable across 5 scanners, suggesting sensitivity to subject-specific connectome. A total of 75 TS and more than two thousand patients with various psychiatric and neurological disorders are scheduled to participate in the project, allowing a mixed model statistical harmonization. The HARP protocols are publicly available online, and all the imaging, demographic and clinical information, harmonizing database will also be made available by 2024. To the best of our knowledge, this is the first project to implement a prospective, multi-level harmonization protocol with multi-site TS data. It explores intractable brain disorders across the lifespan and may help to identify the disease-specific pathophysiology and imaging biomarkers for clinical practice.