On the etiology of internalizing and externalizing problem behavior: A twin-family study

Associations of depression and anxiety symptoms in childhood and adolescence with epigenetic aging

BACKGROUND

Childhood anxiety and depression symptoms are potential risk factors for accelerated biological aging. In child and adolescent twins, we tested whether these symptoms were associated with DNA methylation (DNAm) aging, a measure of biological aging.

METHODS

276 twins (135 pairs, 6 singletons) had DNAm assayed from saliva in middle childhood (mean = 7.8 years). Residuals of five different DNAm age estimates regressed on chronological age were used to indicate accelerated aging. Anxiety and depression symptoms were assessed in middle childhood and early adolescence using the Child Behavior Checklist. Mixed effect regression was used to examine potential relationships between anxiety or depression symptoms, and accelerated DNAm age. MZ twin difference analysis was then utilized to determine if associations were environmentally-driven or due to genetic or shared-environment confounding.

RESULTS

Anxiety and depression symptoms were not associated with accelerated DNAm aging in middle childhood. In early adolescence, only the Wu clock was significant and indicated that each one symptom increase in anxiety symptoms had an associated age acceleration of 0.03 years (~0.4 months; p = 0.019). MZ twin difference analysis revealed non-significant within-pair effects, suggesting genetic and shared environmental influences.

LIMITATIONS

Sample is predominantly male and white. Generalizability to other populations may be limited.

CONCLUSION

Accelerated DNAm aging of the Wu clock in middle childhood is associated with anxiety, but not depression, symptoms in early adolescence. Further, this association may be the result of shared genetic and environmental influences. Accelerated DNAm aging may serve as an early risk factor or predictor of later anxiety symptoms.

The impact of co-occurring mental health problems on referral to and initiation of treatment among youth under probation supervision: Findings from a cluster randomized trial

INTRODUCTION

Many youth under community supervision have substance use and co-occurring mental health issues. Yet, access to treatment is limited, and many programs cannot address co-occurring disorders. This study examines how co-occurring symptoms among youth on probation affect referral to and initiation of treatment. We hypothesize that both referral and initiation rates will be lower for youth with any co-occurring indicators.

METHODS

This study collected administrative data from 14 sites in three states between March 2014 and November 2017 using JJ-TRIALS, a cluster randomized trial. Among 8552 youth in need of treatment (screened as having a substance use problem, drug possession arrest, positive drug test, etc.), 2069 received a referral to treatment and 1630 initiated treatment among those referred. A co-occurring indicator (n = 2828) was based on symptoms of an internalizing and/or externalizing issue. Descriptive analyses compared referral and initiation by behavioral health status. Two-level mixed effects logistic regression models estimated effects of site-level variables.

RESULTS

Among youth in need with co-occurring internal, external, or both indicators, only 16 %, 18 %, and 20 % were referred to treatment and of those referred, 63 %, 69 %, and 57 % initiated treatment, respectively. Comparatively, 27 % and 83 % of youth with a substance use only indicator were referred and initiated treatment respectively. Multi-level multivariate models found that, contrary to our hypothesis, co-occurring-both (p = 0.00, OR 1.44) and co-occurring-internal indicators (p = 0.06, OR 1.25) predicted higher referral but there were no differences in initiation rates. However, there was substantial site-level variation.

CONCLUSIONS

Youth on probation in need of substance use treatment with co-occurring issues have low referral rates. Behavioral health status may influence youth referral to treatment depending on where a youth is located. Depending on the site, there may be a lack of community programs that can adequately treat youth with co-occurring issues and reduce unmet service needs.

A Multivariate Genome-Wide Association Study Reveals Neural Correlates and Common Biological Mechanisms of Psychopathology Spectra

There is considerable comorbidity across externalizing and internalizing behavior dimensions of psychopathology. We applied genomic structural equation modeling (gSEM) to genome-wide association study (GWAS) summary statistics to evaluate the factor structure of externalizing and internalizing psychopathology across 16 traits and disorders among European-ancestry individuals (n's = 16,400 to 1,074,629). We conducted GWAS on factors derived from well-fitting models. Downstream analyses served to identify biological mechanisms, explore drug repurposing targets, estimate genetic overlap between the externalizing and internalizing spectra, and evaluate causal effects of psychopathology liability on physical health. Both a correlated factors model, comprising two factors of externalizing and internalizing risk, and a higher-order single-factor model of genetic effects contributing to both spectra demonstrated acceptable fit. GWAS identified 409 lead single nucleotide polymorphisms (SNPs) associated with externalizing and 85 lead SNPs associated with internalizing, while the second-order GWAS identified 256 lead SNPs contributing to broad psychopathology risk. In bivariate causal mixture models, nearly all externalizing and internalizing causal variants overlapped, despite a genetic correlation of only 0.37 (SE = 0.02) between them. Externalizing genes showed cell-type specific expression in GABAergic, cortical, and hippocampal neurons, and internalizing genes were associated with reduced subcallosal cortical volume, providing insight into the neurobiological underpinnings of psychopathology. Genetic liability for externalizing, internalizing, and broad psychopathology exerted causal effects on pain, general health, cardiovascular diseases, and chronic illnesses. These findings underscore the complex genetic architecture of psychopathology, identify potential biological pathways for the externalizing and internalizing spectra, and highlight the physical health burden of psychiatric comorbidity.

A Multivariate Genome-Wide Association Study Reveals Neural Correlates and Common Biological Mechanisms of Psychopathology Spectra

There is considerable comorbidity across externalizing and internalizing behavior dimensions of psychopathology. We applied genomic structural equation modeling (gSEM) to genome-wide association study (GWAS) summary statistics to evaluate the factor structure of externalizing and internalizing psychopathology across 16 traits and disorders among European-ancestry individuals (n's = 16,400 to 1,074,629). We conducted GWAS on factors derived from well-fitting models. Downstream analyses served to identify biological mechanisms, explore drug repurposing targets, estimate genetic overlap between the externalizing and internalizing spectra, and evaluate causal effects of psychopathology liability on physical health. Both a correlated factors model, comprising two factors of externalizing and internalizing risk, and a higher-order single-factor model of genetic effects contributing to both spectra demonstrated acceptable t. GWAS identified 409 lead single nucleotide polymorphisms (SNPs) associated with externalizing and 85 lead SNPs associated with internalizing, while the second-order GWAS identified 256 lead SNPs contributing to broad psychopathology risk. In bivariate causal mixture models, nearly all externalizing and internalizing causal variants overlapped, despite a genetic correlation of only 0.37 (SE = 0.02) between them. Externalizing genes showed cell-type specific expression in GABAergic, cortical, and hippocampal neurons, and internalizing genes were associated with reduced subcallosal cortical volume, providing insight into the neurobiological underpinnings of psychopathology. Genetic liability for externalizing, internalizing, and broad psychopathology exerted causal effects on pain, general health, cardiovascular diseases, and chronic illnesses. These findings underscore the complex genetic architecture of psychopathology, identify potential biological pathways for the externalizing and internalizing spectra, and highlight the physical health burden of psychiatric comorbidity.

Associations of externalizing polygenic scores with externalizing disorders among Mexican youth

Several studies have examined the association of externalizing polygenic scores (PGS) with externalizing symptoms in samples of European ancestry. However, less is known about the associations of externalizing polygenic vulnerability in relation to phenotypic externalizing disorders among individuals of different ancestries, such as Mexican youth. Here, we leveraged the largest genome-wide association study on externalizing behaviors that included over 1 million individuals of European ancestry to examine associations of externalizing PGS with a range of externalizing disorders in Mexican adolescents, and investigated whether adversity exposure in childhood moderated these associations. Participants (N = 1064; age range 12-17 years old; 58.8% female) were adolescents recruited for a general population survey on adolescent mental health in the Mexico City Metropolitan region and were genotyped. Childhood adversity exposure and externalizing disorders, specifically attention-deficit hyperactivity disorder (ADHD), conduct disorder, oppositional defiant disorder, and substance use disorder, were assessed via the computer-assisted World Mental Health Composite International Diagnostic Interview for adolescents. A greater externalizing PGS was associated with a greater odds of any externalizing disorder (OR = 1.29 [1.12, 1.48]; p < 0.01) and ADHD (OR = 1.40 [1.15, 1.70]; p < 0.01) in the whole sample, and in females in particular. There were no main effects of the externalizing PGS on conduct disorder, oppositional defiant disorder, or substance use disorder, nor did adversity exposure moderate these associations. Our results suggest that greater genetic propensity for externalizing disorders is associated with increased odds of any externalizing disorders and ADHD among Mexican adolescents, furthering our understanding of externalizing disorder manifestation in this population.

An evaluation of a trauma-informed educational intervention to enhance therapeutic engagement and reduce coercive practices in a child and adolescent inpatient mental health unit

High-risk behaviours are sometimes encountered in Child and Adolescent inpatient mental health units and can prompt the use of coercive practices to maintain safety. Coercive practices may lead to re-traumatisation of young people and deteriorating therapeutic relationships. Trauma-informed practice (TIP) has successfully reduced coercive practices. While education is identified as foundational to implementation, evaluations of programmes remain minimal. The aim of this study was to explore mental health professionals' views and experiences of a trauma-informed education programme and its likely impact on their approach to practice. Five mental health professionals agreed to participate, four contributed in a focus group and one in an individual interview. Data were analysed thematically using the Braun and Clarke Framework. Three main themes were identified. Firstly, shifting attitudes and perceptions of trauma-informed practice. Participants believed they had developed more compassion towards clients and these attitudes were reflected in their clinical practice. Secondly, challenges associated with trauma-informed practice educational intervention. Staffing issues and shift work made it difficult for participants to attend education sessions regularly. Participants identified barriers to practicing in a trauma-informed manner in the current clinical environment. Finally, the need for interdisciplinary communication and support was identified. Participants saw the need for all professionals, not only nurses, to take responsibility for changing practice, and for stronger support at the organisational level. Trauma-informed practice is crucial to recovery-focused mental health nursing practice. These findings highlight the importance of TIP education and suggest areas for further improvement to enhance positive mental health outcomes for young people.

Latent Profiles of Sleep Patterns in Early Adolescence: Associations With Behavioral Health Risk

PURPOSE

The present study characterized sleep profiles in a national longitudinal sample of early adolescents and examined whether profiles predicted later behavioral problems.

METHODS

Three waves of data (2016-2021) were obtained from the Adolescent Behavior and Cognitive Development study, including 3,326 participants with both weekday and weekend sleep data measured by Fitbit wearables (age range 10.58-13.67 years; 49.3% female). Latent profile analysis was utilized to identify sleep profiles using multiple sleep indicators (duration, latency, efficiency, wake minutes, wake counts, and midpoint). We then explored whether demographic predictors predicted profile membership and tested the latent sleep profiles' predictive utility of internalizing and externalizing symptoms.

RESULTS

Four profiles were identified: average sleep (40.39%), high duration & high wakefulness (28.58%), high efficiency, low duration &low wakefulness (16.86%), and low duration & low efficiency (14.17%). Participants with older age, males, higher body mass index, and advanced pubertal status were more likely to be classified in the low duration & low efficiency profile than the average group. Participants with lower income, minority identification, older age, and higher body mass index were more likely to be classified in the high efficiency, low duration &low wakefulness than the average group. Participants with lower parental education and males were more likely to be in the high sleep duration & high wakefulness than the average group. The low duration & low efficiency group had the highest attention problems, social problems, and rule-breaking behaviors.

DISCUSSION

Our findings highlight unique sleep patterns in early adolescence and their prospective links with internalizing and externalizing problems.

Effects of parental mental health and family environment on impulsivity in preadolescents: a longitudinal ABCD study®

Introduction

Impulsivity is a known risk factor for the development of substance use disorders and other psychiatric conditions that is influenced by both genetics and environment. Although research has linked parental mental health to children's impulsivity, potential mediators of this relationship remain understudied. The current investigation leverages the large national Adolescent Brain Cognitive Development (ABCD) Study to assess the mediating role of family conflict - an important social context for youth development - in the relationship between parental mental health and youth impulsivity.

Methods

Data were from the first three annual waves of the ABCD study (Baseline N = 11,876 children, Mage = 9.9 years; 48% female; 52% White). Parental mental health conditions were self-reported internalizing, externalizing, and total problems. Youth completed the family conflict scale, and Urgency, Planning (lack of), Perseverance (lack of), Sensation Seeking, and Positive Urgency (UPPS-P) scale to measure impulsivity. To determine if within-family change in conflict from baseline to year 1 explained changes in the strength of relations between baseline parental mental health and year 2 youth impulsivity, longitudinal causal mediation analyses were conducted, controlling for demographic factors (i.e., age, sex, race, household income, parental education, marital status), as well as baseline levels of family conflict and outcomes. Separate mediation models were run for each mental health condition and each UPPS-P subscale.

Results

Above and beyond bivariate relations, longitudinal mediation models, which included covariates, showed family conflict significantly (ps < 0.001) mediated relations between all three parental mental health conditions and all but one (i.e., sensation seeking) UPPS-P subscales. The proportion mediated through family conflict for internalizing problems and total problems on facets of impulsivity (except sensation seeking) ranged from 9% (for lack of perseverance) to 17% (for lack of planning). Proportion mediated via family conflict for externalizing problems on youth's impulsivity (except sensation seeking) was slightly higher, ranging between 13% (lack of perseverance) to 21% (lack of planning).

Discussion

Family conflict may be an important intergenerational factor linking parental mental health and youth's impulsivity. Addressing parental mental health and family conflict may help curb increased impulsivity in youth, and in turn reduce adolescent substance use disorders.

Self-reported emotional and behavioral problems among school-going adolescents in Nepal-A cross-sectional study

BACKGROUND

Studies on self-reported emotional and behavioral problems (EBPs) among adolescents are still sparse in many low- and middle-income countries. In Nepal, no such studies have been performed on a larger scale, and little is known about self-reported EBPs in the adolescent population.

METHODS

This cross-sectional, school-based study on EBPs included 1904 adolescents aged 11-18 years, enrolled in government and private schools located in 16 districts in Nepal. The Nepali version of the Youth Self Report form was used to assess self-reported EBPs, and the Teacher Report Form was used to assess academic performance. Analysis of variance (ANOVA) was used for gender comparisons on adolescents' EBPs and on academic competence. Multiple regression analysis was done to explore correlates of self-reported EBPs.

RESULTS

The overall prevalence of self-reported EBPs was 14.2%; 15.6% in boys and 12.9% in girls. The mean Total Problems score was 39.27 (standard deviation = 24.16); no gender differences were observed. Boys scored higher on Externalizing Problems and girls scored higher on Internalizing Problems. The effect sizes for gender comparisons were small with Hedges' g ranging from -0.29 to 0.28. Physical illness and negative/traumatic life events were positively correlated with self-reported EBPs, whereas academic performance was negatively correlated. However, the effect sizes were small (η2 < 0.02).

CONCLUSION

This study helps to narrow the knowledge gap on the prevalence, magnitude, and types of self-reported EBPs in Nepali adolescents. It demonstrated an association between self-reported EBPs and academic performance and linked self-reported EBPs to other factors such as negative/traumatic life events and physical illness. The findings might assist health authorities in the planning of mental health services and may also provide valuable background information to clinicians dealing with adolescent mental health problems.

Developmental cascades of behavior problems and cognitive ability from toddlerhood to middle childhood: A 9-year longitudinal study

Little is known about the direction, ordering, and uniqueness of longitudinal associations between behavior problems and cognitive ability, from toddlerhood to middle childhood. A developmental cascade model was tested in the present study to examine the transactional processes in 103 Chinese children at the ages of 1, 2, 7, and 9 years. Behavior problems were assessed using the maternal reported Infant-Toddler Social and Emotional Assessment at the ages of 1, 2 and parental reported Children Behavior Checklist at the ages of 7, 9. Cognitive ability was measured using Bayley Scales of Infant and Toddler Development at the ages of 1, 2 and Wechsler Intelligence Scale for Children at the ages of 7, 9. The results revealed the stability of behavior problems and cognitive ability from age 1 to age 9 years and concurrent associations between externalizing and internalizing problems. Unique longitudinal associations were identified between (1) age 1 cognitive ability and age 2 internalizing problems, (2) age 2 externalizing problems and age 7 internalizing problems, (3) age 2 externalizing problems and age 7 cognitive ability, (4) age 7 cognitive ability and age 9 externalizing problems. The results indicated essential targets for future interventions aimed at reducing children's behavior problems at 2 years old and promoting cognitive ability at 1 year old and 7 years old.

Age-Related Variations of Genetic and Environmental Contributions to the Covariation of Fear, Distress and Externalizing Symptoms: A Twin Study in Childhood and Adolescence

The frequency with which Internalizing and Externalizing symptoms co-occur suggests that, behind both domains, there may be a common susceptibility represented by a general psychopathology factor. However, it's still unclear whether this common susceptibility is affected by age-related variations. Internalizing (i.e., Fear and Distress) and Externalizing symptoms were evaluated in 803 twin pairs from the population-based Italian Twin Registry. Model-fitting analysis was performed separately in the 6-14 and 15-18 age groups to estimate genetic and environmental contributions to the covariance among symptoms. For the 6-14 group, a multivariate Cholesky model best fitted the data, while, for the 15-18 group, the best fit was provided by a Common Pathway model in which nearly 50% of total variance of each trait was mediated by common genetic factors. Our findings support a common susceptibility behind Internalizing and Externalizing symptoms, mainly genetic in origin, that becomes more evident at the beginning of puberty.

Family Structure and Child Behavior Problems in Australia, the United Kingdom, and the United States

A large body of literature suggests that children living with two married, biological parents on average have fewer behavior problems than those who do not. What is less clear is why this occurs. Competing theories suggest that resource deficiencies and parental selectivity play a part. We suggest that examining different contexts can help adjudicate among different theoretical explanations as to how family structure relates to child behavior problems. In this paper, we use data from the Growing Up in Australia: Longitudinal Study of Australian Children (LSAC), the UK Millennium Cohort Study (MCS), and the US Early Childhood Longitudinal Study (ECLS-K) to examine the relationship between family structure and child behavior problems. Specifically, we look at how living in several configurations of biological and social parents may relate to child behavior problems. Findings suggest both similarities and differences across the three settings, with explanations in the UK results favoring selectivity theories, US patterns suggesting that there is a unique quality to family structure that can explain outcomes, and the Australian results favoring resource theories.

Differences in Parenting Behavior are Systematic Sources of the Non-shared Environment for Internalizing and Externalizing Problem Behavior

Although there is evidence for non-shared environmental links between parenting and problem behavior, so far, age-, informant-, and parent-specific patterns for both internalizing and externalizing problem behaviors have not been examined within one study yet. Using the twin differences design, the present study aimed to test how maternal and paternal parenting systematically act as a source of non-shared environment for problem behavior across different age groups and informants. We examined 1327 monozygotic twin pairs and their parents drawn from three birth cohorts of the German TwinLife study. Our results revealed that particularly child-reported less positive and more negative parenting by both parents contribute significantly to the unique environmental variance of problem behavior, although we did not find a clear pattern across age groups. Our study underlines the necessity of controlling for genetic confounding to uncover the truly environmentally mediated (and thus environmentally influenceable) pathways between parenting and problem behavior. A practical implication could be that it may be useful to primarily consider the child's perspective and focus on maternal as well as paternal parenting in interventions that address parenting to reduce problem behavior.

Integrative analysis of genomic and exposomic influences on youth mental health

BACKGROUND

Understanding complex influences on mental health problems in young people is needed to inform early prevention strategies. Both genetic and environmental factors are known to influence youth mental health, but a more comprehensive picture of their interplay, including wide-ranging environmental exposures - that is, the exposome - is needed. We perform an integrative analysis of genomic and exposomic data in relation to internalizing and externalizing symptoms in a cohort of 4,314 unrelated youth from the Adolescent Brain and Cognitive Development (ABCD) Study.

METHODS

Using novel GREML-based approaches, we model the variance in internalizing and externalizing symptoms explained by additive and interactive influences from the genome (G) and modeled exposome (E) consisting of up to 133 variables at the family, peer, school, neighborhood, life event, and broader environmental levels, including genome-by-exposome (G × E) and exposome-by-exposome (E × E) effects.

RESULTS

A best-fitting integrative model with G, E, and G × E components explained 35% and 63% of variance in youth internalizing and externalizing symptoms, respectively. Youth in the top quintile of model-predicted risk accounted for the majority of individuals with clinically elevated symptoms at follow-up (60% for internalizing; 72% for externalizing). Of note, different domains of environmental exposures were most impactful for internalizing (life events) and externalizing (contextual including family, school, and peer-level factors) symptoms. In addition, variance explained by G × E contributions was substantially larger for externalizing (33%) than internalizing (13%) symptoms.

CONCLUSIONS

Advanced statistical genetic methods in a longitudinal cohort of youth can be leveraged to address fundamental questions about the role of 'nature and nurture' in developmental psychopathology.

Polygenic risks for joint developmental trajectories of internalizing and externalizing problems: findings from the ALSPAC cohort

BACKGROUND

Joint developmental trajectories of internalizing and externalizing problems show considerable heterogeneity; however, this can be parsed into a small number of meaningful subgroups. Doing so offered insights into risk factors that lead to different patterns of internalizing/externalizing trajectories. However, despite both domains of problems showing strong heritability, no study has yet considered genetic risks as predictors of joint internalizing/externalizing problem trajectories.

METHODS

Using parallel process latent class growth analysis, we estimated joint developmental trajectories of internalizing and externalizing difficulties assessed across ages 4 to 16 using the Strengths and Difficulties Questionnaire. Multinomial logistic regression was used to evaluate a range of demographic, perinatal, maternal mental health, and child and maternal polygenic predictors of group membership. Participants included 11,049 children taking part in the Avon Longitudinal Study of Parents and Children. Polygenic data were available for 7,127 children and 6,836 mothers.

RESULTS

A 5-class model was judged optimal: Unaffected, Moderate Externalizing Symptoms, High Externalizing Symptoms, Moderate Internalizing and Externalizing Symptoms and High Internalizing and Externalizing Symptoms. Male sex, lower maternal age, maternal mental health problems, maternal smoking during pregnancy, higher child polygenic risk scores for ADHD and lower polygenic scores for IQ distinguished affected classes from the unaffected class.

CONCLUSIONS

While affected classes could be relatively well separated from the unaffected class, phenotypic and polygenic predictors were limited in their ability to distinguish between different affected classes. Results thus add to existing evidence that internalizing and externalizing problems have mostly shared risk factors.