Sibship size, birth order, family structure and childhood mental disorders

Association of only-child status and household pet ownership with attention-deficit/hyperactivity disorder among Chinese preschool children: a population-based study

Background

The associations of only-child status and household pet ownership with the risk of attention-deficit/hyperactivity disorder (ADHD) are inconclusive, and the joint effects of only-child status and household pet ownership on ADHD have not been thoroughly investigated.

Methods

A population-based study was conducted in 2021 involving preschool children aged 3-6 years attending kindergartens in Longhua District, Shenzhen, China. Parents were invited to complete questionnaires providing information on socio-demographic and family-environmental factors. ADHD symptoms were assessed using the 26-item Swanson, Nolan, and Pelham Rating Scale as reported by parents.

Results

This study included 63,282 children (mean age: 4.86 ± 0.85 years, 53.6% boys), representing 72.6% of all preschool children in this district in 2021. Among them, 34.4% were only-child and 9.6% were identified as having ADHD. Only-child status was associated with an increased risk of ADHD [adjusted odds ratio: 1.30 (95%CI: 1.23-1.38). Compared to children without a pet (cats or dogs) at ages 0-3 years, pet ownership at ages only 0-1 year, only 1-3 years, and both ages were associated with increased odds of ADHD: 1.59 (1.30-1.95), 1.58 (1.28-1.93), and 1.66 (1.42-1.92), respectively, after controlling for potential confounders. A significant interaction between pet ownership at only 1-3 years and only-child status was observed (adjusted P for interaction = 0.028). Similar findings were observed when the analyses were performed separately for boys and girls.

Conclusion

Both only-child status and household pet ownership are associated with an increased risk of ADHD; however, the detrimental effect of pet ownership appears to be mitigated among only children when pet exposure occurs at ages 1-3 years, providing new insight into reducing family-related risk factors of ADHD.

Association between childhood trauma and depressive symptoms in adolescents during the post COVID-19 pandemic: the mediating role of social peer rejection

This study aimed to investigate the associations of childhood trauma and its facets with depressive symptoms in depressed adolescents during the post COVID-19 epidemic, and explore the potential mediating role of social peer rejection in these associations. A total of 413 adolescents with depressive disorders completed the Chinese version of the Child Trauma Questionnaire Short Form, the Social Peer Rejection, and the Children's Depression Inventory. Childhood trauma (β = 0.42, p < 0.01) and social peer rejection (β = 0.18, p < 0.01) were positively related to depressive symptoms, after adjustment for demographic factors. Furthermore, social peer rejection partly mediated the relationship between childhood trauma and depressive symptoms, and the mediation effect ratio was 17.0% (p < 0.001). This study found that childhood trauma and social peer rejection are both risk factors for depressive symptoms, and social peer rejection played a mediating role in the relationship between childhood trauma and depressive symptoms.

Cumulative contextual risk, mothers' and fathers' parenting, and adolescents' psychosocial problems in Ghana

Limited research exists on the association between cumulative risk factors and the psychosocial well-being of adolescents in low-income, culturally distinct settings. This study aimed to fill this gap by examining the impact of cumulative risk exposure on Ghanaian adolescents' psychosocial problems and exploring the mediating role of parenting. The study involved 212 adolescents (61% girls; average age = 13.38) who completed measures on cumulative risk, maternal and paternal warmth, behavioral control, anxiety, depression, overt aggression, and relational aggression. The results indicated that cumulative risk indirectly influenced adolescents' depression and overt aggression through paternal warmth. Furthermore, paternal behavioral control mediated the relationship between cumulative risk and adolescents' overt aggression. Findings highlight the importance of fathers' parenting in mediating cumulative risk effects.

Adolescent siblings of children with cancer: Resource-based profiles, normalization, and search for meaning in life

INTRODUCTION

Adolescent siblings of children with cancer jointly face the experience of having a brother or sister with cancer and being in the developmental period of adolescence themselves. Based on Hobfoll's conservation of resources theory, we aimed to identify profiles based on two distinct resources: sense of hope (personal resource) and perceived social support (social resource). Both have been found to be vital for optimal functioning during adolescence. Further, we examined differences in these profiles with regard to two distal outcomes: normalization (a coping strategy) and search for meaning in life (a commonly assumed adolescent developmental task).

METHODS

One hundred and eleven Israeli adolescent siblings (aged 13-17) completed self-report measures.

RESULTS

Two distinct resource-based profiles were identified: "high resources" and "low resources." Participants with "high resources" had a higher sense of hope and higher social support; were significantly more likely to live with married parents than with unmarried parents; had marginally fewer siblings; and scored higher on normalization and search for meaning in life than did participants with "low resources."

CONCLUSIONS

The study outcomes highlight the essential role of resources for this population. Such resources seem to be helpful for normalization, a coping strategy whose focus is on facilitating regular family routines, and for the siblings' search for meaning in life. Practitioners who work with families in the context of childhood cancer should aim to help these siblings obtain key resources, such as social support, and to actively pursue their goals.

Predictors of Attention Deficit Hyperactivity Disorder in Sri Lankan Children: A School Based Community Study

OBJECTIVE

To evaluate potential risk-factors of ADHD among primary school-children (PSC) in state schools in Colombo district of Sri Lanka.

METHOD

A case-control study was conducted with 73 cases and 264 controls selected randomly among 6 to 10-year-old PSC from Sinhala medium state schools in Colombo district. Primary care givers completed the SNAP-IV P/T-S scale to screen for ADHD and an interviewer-administered questionnaire on risk-factors. Children's diagnostic status was confirmed by a Consultant Child and Adolescent Psychiatrist based on DSM-5 criteria.

RESULTS

A binomial regression model identified male sex (aOR = 3.45; 95% CI [1.65, 7.18]), lower educational level of the mother (aOR = 2.99; 95% CI [1.31, 6.48]), birth weight <2,500 g (aOR = 2.83; 95% CI [1.17, 6.81]),a neonatal complications (aOR = 3.82; 95% CI [191, 7.65]) and child having witnessed verbal/emotional aggression between parents (aOR = 2.08; 95% CI [1.01, 4.27])as significant predictors of ADHD.

CONCLUSION

Primary prevention should focus on strengthening neonatal, maternal and child health services within the country.

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.

Birth order and sickness absence: Register-based evidence from Finland

BACKGROUND

In working ages, sickness absence is strongly related to persons' health condition. We studied how birth order was associated with receipt of sickness allowance, distinguishing between mental disorders, musculoskeletal disorders and injuries.

METHODS

A follow-up study based on the entire Finnish population was conducted for sibling groups born 1969-1982, in which each sibling was observed from age 35 years in the period 2004-2018. Focus was on within-family variation in first-time sickness allowance receipt.

RESULTS

Results of stratified Cox regressions revealed that each increase in birth order was associated with a slightly higher risk of sickness absence from any cause. For mental disorders, associations were stronger; the hazard ratio as compared to first borns was 1.03 (95% CI: 0.98-1.08) of second borns, 1.10 (0.99-1.22) of third borns, and 1.52 (1.25-1.85) of fourth or higher borns. Corresponding numbers for musculoskeletal disorders were 1.12 (1.07-1.17), 1.19 (1.09-1.30) and 1.15 (0.96-1.38), and for injuries 1.06 (1.01-1.12), 1.09 (1.21-1.14) and 0.96 (0.77-1.20), respectively.

CONCLUSIONS

Birth order effects were generally stronger for women than men, and to some extent influenced by educational level, occupation, income, and family composition. Possible latent mechanisms behind the associations may relate to within-family dynamics at childhood.

Gendered Associations between Single Parenthood and Child Behavior Problems in the United Kingdom

Internalizing and externalizing behavior problems are associated with a variety of negative child outcomes, but these conclusions have been drawn from research that usually compares children in families with two biological, married parents to all other family types. We compare behavior problems across two-parent, single-mother, and single-father families, which allows us to explore competing gender theories as possible explanations for why child behavior outcomes may be different across these three categories. Results from analyses of the UK Millennium Cohort Study suggest that while children in both single-mother and single-father families initially look like they experience more behavior problems than those in two-parent families, controlling for physical and, especially, social resources explains potential differences. Similarly, when single mothers and single fathers occupy similar family environments in terms of physical and social resources, their children report similar behavior. In contrast to findings from the US, children of single mothers who occupy similar family environments as children in two-parent families in terms of resources perform slightly better in terms of externalizing behavior problems than their two-parent counterparts. We conclude that constructivist theories more accurately explain gendered parenting behavior and its consequences for child behavior problems. Environmental factors such as income, parental closeness, and participation in extracurricular activities have a significant effect on child behavior problems.

Comparing Children's Behavior Problems in Biological Married, Biological Cohabitating, and Stepmother Families in the UK

A large body of research shows that children who live with two married biological parents have lower levels of externalizing and internalizing behavior problems compared to their peers in other family structure, including cohabitating biological families. Such patterns suggest that marriage provides a uniquely protective family environment, though we know less about children in the obvious counterfactual case: married stepfamilies. While research suggests children with stepfathers have more behavior problems than those living with married biological parents, we know little about how children with stepmothers fare, or how children with stepparents fare compared to those living with cohabiting biological parents. We use the Millennium Cohort Study (MCS) sweep 6 to compare children living with married biological parents, married fathers and stepmothers, and cohabiting biological parents. We find that family structure has no significant relationship with children's internalizing behavior problems, but that children living with a stepmother and biological cohabitating families exhibit more externalizing behavior problems than do those living with married biological parents. Covariates that indicate both physical and social family environments must be considered together to explain differences in married-parent families on externalizing behavior problems.

The effect of birth order on length of hospitalization for pediatric traumatic brain injury: an analysis of the 1987 Finnish birth cohort

Purpose

This study examines the relationship between birth order and length of hospitalization due to pediatric traumatic brain injury (TBI).

Methods

We prospectively followed 59,469 Finnish newborns from 1987 until age 18 years. Data on first diagnosis of TBI was recorded within the 1987 Finnish Birth Cohort (FBC). Hospitalization period was divided into two categories: 2 days or less and more than 2 days. The latter was considered in this study as longer hospitalization.

Results

Compared with first born siblings, later born siblings had an increased risk of a longer hospitalization for TBI (12.7% of fourth or higher born birth children diagnosed with TBI were hospitalized for 2 or more days, 11.3% of first born, 10.4% of third born and 9.0% of second born). Fourth or higher born children were more likely to experience a repeat TBI; 13.4% of fourth or higher born children diagnosed with TBI had 2–3 TBIs during the study period compared to 9% of third born, 7.8% of second born and 8.8% of the first born. Injuries in the traffic environment and falls were the most common contributors to pediatric TBI and occurred most frequently in the fourth or higher birth category; 29.3% of TBIs among fourth or higher birth order were due to transport accidents and 21% were due to falls.

Conclusions

This study revealed a significant increase in risk for longer hospitalization due to TBI among later born children within the same sibling group. The study provides epidemiological evidence on birth order as it relates to TBI, and its potential to help to explain some of the statistical variability in pediatric TBI hospitalization over time in this population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13690-022-00919-x.

Birth order and pediatric traumatic brain injury

Pediatric traumatic brain injury (TBI) is a significant problem of public health importance worldwide. Large population-based studies on the effect of birth order on health phenomena are exceedingly rare. This study examines the relationship between birth order and risk for pediatric TBI among sibling groups. We performed a retrospective cohort study following 59,469 Finnish newborns from 1987 until age 18 years. Data on first diagnosis of TBI was recorded within the 1987 Finnish Birth Cohort (FBC). Compared with first born siblings, later born siblings had an increased risk of TBI during the follow-up period (hazard ratio [HR] 1.02; 95% confidence interval [CI] 0.91–1.14 for second born, HR 1.09; 95% CI 0.95 1.26 for third born, HR 1.28; 95% CI 1.08–1.53 for fourth or higher). When adjusted for sex and maternal age at child’s birth, HRs (95% CIs) for TBI during the follow-up period were 1.12 (0.99–1.26) for second born, 1.31 (1.12–1.53) for third born and 1.61 (1.33–1.95) for fourth born or higher children, respectively. Within this large register-based population-wide study, order of birth modified risk for pediatric TBI among sibling groups. Taken together, these study findings may serve to stimulate further inquiry into genetic, psychological, or psychosocial factors which underlie differences in risk and depth of effect within and between sibling groups.

Birth order and socioeconomic disadvantage predict behavioural and emotional problems at age 3 years

AIM

The aim of this study was to describe sociodemographic and family predictors for behavioural and emotional problems in pre-schoolers.

METHODS

This was a cross-sectional study including 30,795 children in the Stockholm region whose parents had completed the Strength and Difficulties Questionnaire (SDQ) prior to a routine visit to a well-baby clinic at age 3 years. Multivariate logistic regression was used to analyse predictors for having a high total SDQ difficulties score.

RESULTS

Young parental age and a low level of parental education predicted high total SDQ score in a stepwise pattern. Being a first-born child was associated with a high SDQ score with an adjusted odds ratio of 2.10 (95% C.I. 1.84-2.41), compared with having older siblings. A sole physical custody arrangement predicted a high total SDQ score after parental separation. The percentage of children with a high total SDQ score increased with the Care Need Index (CNI) of the well-baby clinic.

CONCLUSIONS

This study identified socioeconomic disadvantage and being the first-born child as the main predictors of poor mental health at age 3 years. Well-baby clinics with socioeconomically disadvantaged catchment areas should be provided with adequate resources and methods for equitable prevention.

U.S. national, regional, and state-specific socioeconomic factors correlate with child and adolescent ADHD diagnoses pre-COVID-19 pandemic

Attention-deficit/hyperactivity disorder (ADHD), the most diagnosed emerging neurodevelopmental disorder in children, is a growing health crisis in the United States. Due to the potential increase in ADHD severity during and post the COVID-19 pandemic, we analyzed recent national and two state-specific ADHD data distribution among U.S. children and adolescents by investigating a broad range of socioeconomic status (SES) factors. Child and adolescent ADHD diagnosis and treatment data were parent-reported via National Survey of Children's Health (NSCH). The nationwide childhood prevalence of ADHD is 8.7%, and 62.1% of diagnosed children are taking medication. Louisiana (15.7%) has the highest percentage of children diagnosed with ADHD and California (5.6%) has the lowest, followed by Nevada (5.9%). Multiple correspondence analysis (MCA, n = 51,939) examining 30 factors highlights four areas of interest at the national and state level: race/ethnicity, financial status, family structure, and neighborhood characteristics. Positive correlations between ADHD diagnosis and unsafe school, unsafe neighborhood, and economic hardship are evident nationally and statewide, while the association between a lack of ADHD diagnosis and higher urban neighborhood amenities are evident nationally, but not in two opposing outlier states-Louisiana or Nevada. National and state-specific hierarchical analyses demonstrate significant correlations between the various SES factors and ADHD outcomes. Since the national analysis does not account for the demographic heterogeneity within regions or individual states, the U.S. should rely on comprehensive, county-specific, near real-time data reporting to effectively model and mitigate the ADHD epidemic and similar national health crises.

Larger thalamus correlated with inattentive severity in the inattentive subtype of ADHD without comorbidity

Previous studies of brain structural abnormalities in attention-deficit/hyperactivity disorder (ADHD) samples scarcely excluded comorbidity or analyzed them in subtypes. This study aimed to identify neuroanatomical alterations related to diagnosis and subtype of ADHD participants without comorbidity. In our cross-sectional analysis, we used T₁-weighted structural MRI images of individuals from the ADHD-200 database. After strict exclusion, 121 age-matched children with uncomorbid ADHD (54 with ADHD-inattentive [iADHD] and 67 with ADHD-combined [cADHD]) and 265 typically developing control subjects (TDC) were included in current investigation. The established method of voxel-based morphometry (VBM8) was used to assess global brain volume and regional grey matter volume (GM). Our results showed that the ADHD patients had more regional GM in the bilateral thalamus relative to the controls. Post hoc analysis revealed that regional GM increase only linked to the iADHD subtype in the right thalamus and precentral gyrus. Besides, the right thalamus volume was positively related to inattentive severity in the iADHD. There were no group differences in global volume. Our results provide preliminary evidence that cerebral structural alterations are tied to uncomorbid ADHD subjects and predominantly attribute to iADHD subtype. Furthermore, the volume of the right thalamus may be relevant to inattentive symptoms in iADHD possibly related to a lack of inhibition of irrelevant sensory input.

Research Review: Developmental origins of depression - a systematic review and meta-analysis

BACKGROUND

Many observational studies have found a direct association between adverse in utero, perinatal and postnatal exposures and offspring's depression. These findings are consistent with the 'developmental origins of disease hypothesis'. But no review has comprehensively summarized the roles of these exposures. This review aims to systematically scrutinize the strength of associations between individual prenatal, perinatal, and postnatal exposures and subsequent depression in offspring.

METHODS

We conducted a systematic review and meta-analysis to synthesize the literature from the EMBASE, HealthStar, PsychoInfo, and Medline databases since their inception to September 1, 2019. English language articles on population-based prospective cohort studies examining the associations between in utero, perinatal, and postnatal exposures and offspring's depression were searched. Random-effects models were used to calculate pooled estimates, and heterogeneity and sensitivity tests were conducted to explore potential confounders in the relationships of depression and early-life factors. Qualitative analysis was also conducted.

RESULTS

Sixty-four prospective cohort studies with 28 exposures studied in the relationships to offspring's depression met inclusion criteria. The meta-analysis found 12 prenatal, perinatal, and postnatal characteristics were associated with an increased risk of depression in offspring: low birth weight, premature birth, small gestational age, maternal education, socioeconomic status, having younger parents (<20 years), having older parents (≥35 years), maternal smoking, paternal smoking, maternal stress, maternal anxiety, and prenatal depression. Heterogeneity and sensitivity tests supported the findings. By and large, study characteristics had no effects on conclusions. Qualitative analyses generally supported the findings of meta-analysis and reported on additional risk factors.

CONCLUSIONS

This review provides a robust and comprehensive overview of the lasting psychopathological effects of in utero, perinatal, and postnatal exposures. The findings highlight the need for clinical and public health interventions focusing on the identified risk factors. Large prospective cohort studies are warranted to investigate the combined effects of multiple co-existing early-life exposures.

The whole is greater than the sum of its parts: profiles of multiple mental health risk factors using Latent class analysis

BACKGROUND

The exposure to an accumulation of various risk factors during childhood and adolescence relative to a single risk is associated with poorer mental health. Identification of distinct constellations of risk factors is an essential step towards the development of effective prevention strategies of mental disorders. A Latent class analysis (LCA) extracts different combinations of risk factors or subgroups and examines the association between profiles of multiple risk and mental health outcomes.

METHODS

The current study used longitudinal survey data (KiGGS) of 10,853 German children, adolescents and young adults. The LCA included 27 robust risk and protective factors across multiple domains for mental health.

RESULTS

The LCA identified four subgroups of individuals with different risk profiles: a basic-risk (51.4%), high-risk (23.4%), parental-risk (11.8%) and social-risk class (13.4%). Multiple risk factors of the family domain, in particular family instability were associated with negative mental health outcomes (e.g. mental health problems, depression, ADHD) and predominately comprised late adolescent girls. The social environment represented a more common risk domain for young males.

CONCLUSION

The understanding of multiple risk and different risk "profiles" helps to understand and adjust targeted interventions with a focus on vulnerable groups.

Maternal spontaneous abortion and the risk of attention-deficit/hyperactivity disorder in offspring: a population-based cohort study

STUDY QUESTION

Is a maternal history of spontaneous abortion (SA) associated with an increased risk of attention-deficit/hyperactivity disorder (ADHD) in offspring?

SUMMARY ANSWER

Our results suggest an association between maternal history of SA and ADHD in offspring, with the risk increasing with the number of maternal SA and highest in the firstborn children whose mothers had had recurrent SAs after adjusting for a number of potential confounders.

WHAT IS KNOWN ALREADY

A history of SA has been associated with more complications in next pregnancies and adverse childbirth outcomes, which are risk factors for ADHD in the offspring. However, no previous study has investigated whether maternal SA increases risk of ADHD in the offspring.

STUDY DESIGN, SIZE, DURATION

This population-based study included all live-born children in Denmark from 1 January 1995 to 31 December 2012 (n = 1 062 667). All children were followed from 3 years of age until the day of ADHD diagnosis, death, emigration or 31 December 2016, whichever came first.

PARTICIPANTS/MATERIALS, SETTING, METHODS

There were 130 206 (12.2%) children born to mothers who had at least one SA. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

MAIN RESULTS AND THE ROLE OF CHANCE

During a median follow-up of 9.4 years (interquartile range, 5.4-14.3), 25 747 children were diagnosed with ADHD. Overall, children of mothers with a history of SA had an increased rate of ADHD (HR, 1.11; 95% CI, 1.07 to 1.15). The HRs increased with the number of maternal SA, 1.09 (95% CI, 1.05 to 1.13) for one SA and 1.22 (95% CI, 1.12 to 1.33) for at least two SAs, respectively. These findings were consistent when we took into consideration a number of factors, such as maternal socioeconomic status, type of SA, birth order, parental history of psychiatric disorders, pregnancy characteristics and adverse birth outcomes.

LIMITATIONS, REASONS FOR CAUTION

Misclassification of SA was possible as we used population-based register data to capture maternal history of SA. However, any misclassification of maternal history of SA would be non-differential with regard to the diagnosis of ADHD in offspring, which generally leads to underestimation of the associations. Furthermore, probabilistic sensitivity analysis suggested that only 1% of change in the estimate may have been due to misclassification of SA.

WIDER IMPLICATIONS OF THE FINDINGS

SA is quite frequent (varying from 15 to 20%), and a small increase of neurodevelopmental problems in offspring could have major public health implications.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by grants from the National Natural Science Foundation of China (No. 81703237, No. 81530086 and No. 81761128035), National Key Research and Development Program (2018YFC1002801, 2016YFC1000505), Shanghai Municipal Commission of Health and Family Planning (No. 2017ZZ02026, No. 2017EKHWYX-02), the Novo Nordisk Foundation (NNF18OC0052029), the Danish Council for Independent Research (DFF-6110-00019), the Nordic Cancer Union (176673, 186200 and R217-A13234-18-S65), Karen Elise Jensens Fond (2016) and Xinhua Hospital of Shanghai Jiao Tong University School of Medicine (2018YJRC03). All authors report no conflict of interest.

TRIAL REGISTRATION NUMBER

NA.

Association of Birth Order With Mental Health Problems, Self-Esteem, Resilience, and Happiness Among Children: Results From A-CHILD Study

Objective: This study aimed to investigate the association of birth order with mental health problems, self-esteem, resilience, and happiness among children aged 9-10 years. Methods: This was a cross-sectional study using data from the Adachi Child Health Impact of Living Difficulty (A-CHILD) study, which was a population-based study of children in fourth grade in public schools in Adachi City, Tokyo, Japan in 2018 (N = 3,744). Parent-rated Strengths and Difficulties Questionnaire (SDQ) and self-rated resilience, happiness, and self-esteem score were used to assess child mental health. Multiple regression analysis for continuous outcomes and logistic regression for dichotomous outcomes were used to examine the association of birth order with mental health problems, resilience, happiness, and self-esteem. The analysis was controlled for child sex, mother's age, mother's education, caregiver's depressive symptoms, household income, and living with grandparents. Results: Last-borns showed the lowest total difficulties score in the SDQ, while only children showed the highest (p < 0.001). The highest prosocial behaviors score was found among last-borns (p < 0.001). Resilience score was also highest among last-borns, followed by first-borns, middle-borns, and only children. The lowest happiness score was found among middle-borns. Self-esteem score did not differ by sibling types. These associations were similar in the adjusted model and dichotomized outcomes model. Conclusions: Differential impacts of birth order on child mental health, for both positive and negative sides, were found. Further research is warranted to elucidate the mechanism of the association between birth order and the development of behavior problems and the positive aspects such as resilience, happiness, and self-esteem among children.

Association Between Family Structure and Anxiety Disorder Among Pre-schoolers: A Cross-Sectional Study in Urban Chongqing, China

Objective: This study explores the current situation of anxiety disorder of pre-schoolers and assesses the association between family structure and anxiety disorder (AD) among pre-schoolers in Chongqing, China. Methods: This is a cross-sectional study of 499 main fosterers of children aged 3-6 years who completed the 28-item Chinese version of the Spence Pre-school Anxiety Scale (PAS). Multinomial logistic regression with three models was used to assess the association of the family structure with the different AD. Results: The prevalence of AD was 31.46%, whose score of PAS were more than 48. Among the five different PAS sub-scales, the prevalence of obsessive-compulsive disorder (OCD) was the highest (50.10%), followed by separation anxiety disorder (SAD, 39.28%), fear of physical harm (FPH, 37.68%), generalized anxiety disorder (GAD, 33.47%), and social phobia (SP, 25.85%). Pre-schoolers from inter-generational families were more probably have AD than those from nuclear families (OR = 3.73, p < 0.05). The participants from inter-generational families were more likely to have SAD (OR = 3.39, p < 0.05), FPM (OR = 2.80, p < 0.05), or OCD (OR = 2.40, p < 0.05), in comparison with participants from other family structures. Conclusion: Anxiety disorder among pre-schoolers aged 3-6 in Chongqing is widespread. Pre-schoolers from inter-generational families were more probably have AD, SAD, FPM, and OR and pre-schoolers from stem families may be less likely to have SAD compared with those from nuclear families. Relieving the anxiety of pre-schoolers may be possible with additional interventional efforts in inter-generational families.

Maternal serum Vitamin B12 and offspring attention-deficit/hyperactivity disorder (ADHD)

Maternal Vitamin B12 deficiency during pregnancy is associated with offspring neuropsychiatric disorders. Few previous studies examining this association with attention-deficit/hyperactivity disorder (ADHD) report inconsistent findings. The study examines the association between maternal serum Vitamin B12 levels and offsprings' risk of ADHD. This study is based on the Finnish Prenatal Study of ADHD with a nested case-control design. All the singleton children born in Finland between January 1998 and December 1999 and diagnosed with ADHD were included in the study. A total of 1026 cases were matched with an equal number of controls on sex, date of birth and place of birth. Maternal Vitamin B12 levels were assessed using a chemiluminescence microparticle immunoassay and archived from maternal serum banks, collected during the first and early second trimester of pregnancy. Lower maternal Vitamin B12 levels when analyzed as a continuous variable was not associated with offspring ADHD (aOR 0.97, 95% CI 0.79-1.18, p = 0.75). No significant associations were seen in the lowest quintile of Vitamin B12 levels (aOR 0.96, 95% CI 0.73-1.27, p = 0.80). This is the first study examining maternal sera Vitamin B12 levels during early pregnancy and offspring ADHD. The result suggests that Vitamin B12 deficiency during early pregnancy has specificity for some disorders but not with offspring ADHD.

Siblings and Birth Order-Are They Important for the Occurrence of ADHD?

Objective: The associations of birth order, number of siblings, and ADHD was examined. Method: The analysis based on representative, epidemiological data from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) study (N = 13,488). Results: An increased risk for ADHD in firstborn versus youngest born children (odds ratio [OR] = 1.31, 95% confidence interval [CI] [1.09, 1.58]) and also versus children with no sibling (OR = 1.31, 95% CI [1.03, 1.68]) was revealed, while number of siblings was not associated with ADHD. Results remained stable after controlling for confounders. Conclusion: Firstborn children may receive simultaneously less parental resources and more responsibilities if younger siblings are born. This happens during the vulnerable developmental period of ADHD. In addition, due to higher levels of insecurity, parents are assumed to focus more on potential physical or psychological abnormities in their firstborn children. This may result in a diagnostic bias in firstborn children.

Family structure and alcohol use disorder: a register-based cohort study among offspring with and without parental alcohol use disorder

AIMS

To assess whether parental alcohol use disorder (AUD) is associated with higher risks of living in a non-intact family and assess whether non-intact family structure is associated with higher risks of AUD in the offspring.

DESIGN

Prospective cohort study.

SETTING

Danish nation-wide registries.

PARTICIPANTS

A total of 9948 parental AUD offspring and 98 136 reference offspring from the Danish population.

MEASUREMENTS

Family structure assessed at birth and at each birthday until age 15 as intact or non-intact (with mother only, father only or neither parent); years lived in an intact family defined as total number of years lived with both parents from birth until the 15th birthday; AUD defined as registration in medical, treatment and cause of death registries. Data were analyzed by Cox regression.

FINDINGS

At birth, 30.9% [95% confidence interval (CI) = 29.1-32.6] of parental AUD offspring and 10.7% (95% CI = 10.3-11.0) of reference offspring lived in a non-intact family. At age 15, the numbers were 84.6% (95% CI = 83.9-85.3) and 38.4% (95% CI = 38.1-38.7). Parental AUD was associated with a higher risk of offspring AUD [hazard ratio (HR) = 1.88, 95% CI = 1.74-2.02]. Offspring were at lower risk of AUD if they lived 15 years in an intact family compared with offspring who never lived in an intact family (HR = 0.67, 95% CI = 0.52-0.87 for those with parental AUD, and HR = 0.53, 95% CI = 0.48-0.59 for those whose parents did not have AUD). Findings were inconclusive as to whether or not an association was present between family structure and AUD among offspring with parental AUD and reference offspring.

CONCLUSIONS

The prevalence of non-intact family structure appears to be higher in offspring of parents with alcohol use disorder (AUD) than among offspring from the general population. Parental AUD appears to be associated with increased risk of offspring AUD, and non-intact family structure appears to be associated with increased risk of offspring AUD regardless of parental AUD.

Association between problematic behaviors and individual/environmental factors in difficult children

BACKGROUND

Difficult children are ones whose behavior deviates from the norm, which manifests as restlessness, violence, and difficulty in separating from the mother. Such problematic behaviors usually exhaust their parents during child rearing. This study aimed to identify individual and environmental factors that influence children's problematic behavior, which could be helpful in supporting parents' child rearing.

METHODS

Records of children's problematic behaviors and their individual or environmental information were collected from 8691 children at their 5-year-old health checks. Problematic behaviors were divided into three categories; anxious behaviors, developmental behaviors, and personal habits. Individual factors included sex, parental age, birth order, birth weight, and birth abnormalities. The environmental factors were mother's smoking during pregnancy or currently, partner's cooperation in child rearing, having someone to consult about child rearing, and television viewing time. Using logistic regression, we identified the association between such behaviors and aggravating factors.

RESULTS

Problematic behavior was identified in 2.2%, 11.5%, and 16.1% of cases, respectively, with regard to anxious behaviors, developmental behaviors, and personal habits. The individual factors (including birth order and birth abnormality), and the environmental factors (including mothers currently smoking, lack of someone to consult about child rearing, and long television-watching time) were associated with the odd ratio of increased risk for some problematic behaviors.

CONCLUSION

Behaviors in difficult children are not influenced by individual factors but by several environmental factors. To reduce the parental child rearing burden, health providers should be aware of these aggravating factors.

Maternal serum C-reactive protein (CRP) and offspring attention deficit hyperactivity disorder (ADHD)

Exposure to infection and inflammation during the fetal period are associated with offspring neuropsychiatric disorders. Few previous studies have examined this association with ADHD with mixed findings. This study aims to examine the association between early gestational maternal C-reactive protein (CRP), prospectively assayed in stored maternal sera and the risk of ADHD in offspring. This study is based on the Finnish Prenatal studies of ADHD (FIPS-ADHD) with a nested case-control design. It includes all singleton-born children in Finland between January 1, 1998 and December 31, 1999 and diagnosed with ADHD. A total of 1079 cases and equal number of controls were matched on date of birth, sex and place of birth. Maternal CRP levels were assessed using a latex immunoassay from archived maternal serum specimens, collected during the first and early second trimester of pregnancy. Elevated maternal CRP when analyzed as a continuous variable was not associated with offspring ADHD (OR 1.05, 95% CI 0.96-1.15). No significant associations were seen in the highest quintile of CRP (OR 1.18, 95% CI 0.88-1.58). The results were similar in both sexes as well as among ADHD cases with or without comorbid ASD or conduct disorder. In this first study examining CRP, a biomarker for inflammation, during early pregnancy in relation to offspring ADHD, we report no significant associations. The lack of any association, when considered with positive findings seen in ASD and schizophrenia, and negative findings in bipolar disorder suggests different pathways linking maternal immune activation and development of various neuropsychiatric disorders.

Associations between birth order with mental wellbeing and psychological distress in midlife: Findings from the 1970 British Cohort Study (BCS70)

BACKGROUND

Previous research indicated that birth order was associated with physical health outcomes in adulthood. However, evidence on its association with mental health was lacking. The aim of this study was to investigate if birth order was associated with mental wellbeing and psychological distress at mid-life, stratified by gender, and taking into account confounding factors in childhood and adulthood.

METHOD

The sample consisted of 9,354 participants of the 1970 British Cohort Study (BCS70). The Warwick Edinburgh Mental Wellbeing Scale (WEMWBS), the Malaise Index and attending a doctor's consultation in the past year for a mental health issue at age forty-two were used to assess mental wellbeing and psychological distress in midlife. Birth order was ascertained via a parental questionnaire and referred to the numerical birth position of the participants. The associations between birth order, mental wellbeing and psychological distress were tested using linear and logistic regression adjusting for birth characteristics: smoking during pregnancy, maternal age, mother's marital status, father's employment, region of birth, parental years of education and parental social class, and factors at age 42: years of education, employment status and partnership status. Potential mediating variables including breastfeeding and birthweight at birth and parental separation and conduct disorder measured at age ten were also taken into account.

RESULTS

We find no evidence to support an association between birth order and midlife psychological distress or attending a doctor's consultation in both men and women. In unadjusted analysis, there was an association between birth order four and above and a reduced WEMWBS score of -0.79 (95% CI -1.57, -0.02) in men only. This association was attenuated after adjusting for birth characteristics and mediators at birth (0.86, 95% -1.78, 0.07) but was maintained once conduct disorder at age 10 was accounted for (-1.19, 95% CI -2.28, -0.09). However, this association was attenuated once again after adjusting for employment status, years in education and partnership status in adulthood (-1.04, 95% CI -2.11, 0.03).

CONCLUSIONS

In this study, birth order was not associated with psychological distress or having a mental health issue at midlife. Accounting for employment status, years of education and partnership status in adulthood attenuated the relationship between birth order and mental wellbeing.

Family structure, birth order, and aggressive behaviors among school-aged boys with attention deficit hyperactivity disorder (ADHD)

PURPOSE

To evaluate the associations between family structure, birth order, and aggressive behaviors among school-aged boys with attention deficit hyperactivity disorder (ADHD).

METHODS

We conducted a matched case-control study. Data were retrieved from medical records at a psychiatry center in northern Taiwan. School-aged boys with ADHD who first visited the outpatient department at the psychiatric center between 2000 and 2011 were identified. The Child Behavior Checklist was used for aggressive behavior assessment. Boys with ADHD with T scores higher than 70 on the aggressive subscale were classified as cases and others with T scores lower than 70 were classified as controls at a 1:4 ratio. After controlling for other familial, personal, and parental factors, a multivariate conditional logistic regression was performed to evaluate the effects of family structure and birth order on aggressive behaviors of boys with ADHD.

RESULTS

277 cases and 1108 controls were included in the final analysis. Compared with living in a traditional family with both parents, living in a non-traditional family in which one or both parents were absent increased the risk of aggressive behaviors by 1.47-fold, with the highest risk for those in single parent families. Being the firstborn increased risk by 1.45-fold and the risk was higher when the firstborn had siblings.

CONCLUSIONS

Living in non-traditional families in which one or both parents were absent, and being the firstborn increased risk of aggression in school-aged boys with ADHD. Identification of this high-risk population and development of adequate preventive strategies are warranted.

Lower Apgar scores and Caesarean sections are related to attention-deficit/hyperactivity disorder

AIM

We examined the associations between prenatal, birth-related and newborn risk factors and attention-deficit/hyperactivity disorder (ADHD).

METHODS

In this population-based study, 10 409 subjects diagnosed with ADHD by 31 December 2011 and 39 124 controls, born between 1 January 1991 and 31 December 2005, were identified from Finnish nationwide registers. Perinatal data were obtained from the Birth Register. Conditional logistic regression was used to examine the associations after controlling for confounders.

RESULTS

Lower Apgar scores were associated with a higher risk of ADHD, with odds ratios of 1.12 (95% confidence intervals 1.06-1.19) for one-minute Apgar scores of 7-8, 1.17 (95% CI 1.02-1.35) for scores of 5-6 and 1.41 (95% CI 1.18-1.68) for scores of 0-4, compared to Apgar scores of 9-10. Elective Caesarean sections were associated with an increased risk of ADHD with an adjusted odds ratio of 1.15 (95% CI 1.05-1.26). Other identified risk factors were breech presentation, induced labour and admission to a neonatal intensive care unit. Low umbilical artery pH did not increase the risk of ADHD.

CONCLUSION

Elective Caesareans and perinatal adversities leading to lower Apgar scores increased the risk of ADHD. Future research to identify the mechanisms behind these findings is warranted.

Maternal Smoking During Pregnancy and the Risk of Psychiatric Morbidity in Singleton Sibling Pairs

Introduction

Maternal smoking during pregnancy has been associated with an increased risk for psychiatric morbidity. We further studied this with Finnish siblings to control for genetic/familial factors.

Methods

From the Finnish Medical Birth Register, sibling pairs were selected as the first two children born 1987-1995 to the same mother (n = 150 168 pairs), along with information on maternal smoking (no smoking/smoking). Information on the children's psychiatric diagnoses related to outpatient care visits (1998-2013) and inpatient care (1987-2013), and the mothers' psychiatric morbidity (1969-2013) was derived from the Finnish Hospital Discharge Register. The first pair analysis compared siblings of mothers who only smoked in the first pregnancy (Quitters, 4.7%) and mothers who smoked in both pregnancies (Smokers, 9.6%); the second analysis included mothers who smoked only in the second pregnancy (Starters, 3.3%) and mothers who did not smoke in either pregnancy (Nonsmokers, 77.5%). Smoking information was missing for 5.0% of pairs. Psychiatric morbidity of the siblings and mother was included in the statistical analyses.

Results

The risk of psychiatric diagnoses was significantly lower for the second child of quitters (adjusted OR 0.77, 95% CI 0.72-0.83) compared to the risk among smokers. A higher risk for psychiatric diagnoses was found for the second child of starters (1.39, 1.30-1.49) compared to the risk among nonsmokers. The effect of smoking was more robust for externalizing diagnoses.

Conclusions

Maternal smoking was independently associated with a higher risk for psychiatric morbidity in children, even when controlling thoroughly for genetic and familial factors.

Implications

Maternal smoking during pregnancy has an independent effect on the risk of psychiatric morbidity in children, even after controlling for non-measurable genetic/familial factors by using a sibling pair design. The effect of maternal smoking was robust for externalizing diagnoses. Maternal smoking during pregnancy had an effect on diagnoses both in outpatient and inpatient care.

Family structure and childhood mental disorders: new findings from Australia

PURPOSE

Many children now live in non-traditional families-including one-parent, blended, and step families. While a substantial body of international evidence indicates that these children display poorer cognitive and socio-emotional outcomes than children living in traditional families, research on childhood mental disorders is scarce. This report provides new evidence of the relationships between family structure and childhood mental disorders in an under-researched context, Australia.

METHODS

We use recent, nationally representative data on children aged 4-17 from Young Minds Matter, the second Australian Child and Adolescent Survey of Mental Health and Well-being (N = 6310). Mental disorders were assessed using the Diagnostic Interview Schedule for Children-Version IV and included social phobia, separation anxiety disorder, generalised anxiety disorder, obsessive-compulsive disorder, major depressive disorder, attention-deficit/hyperactivity disorder, and conduct disorder.

RESULTS

Compared to children living in original families, children in one-parent, blended, and step families experienced a higher prevalence of mental disorders. Amongst children whose parents separated, the time since separation was not statistically significantly related to the prevalence of mental disorders.

CONCLUSIONS

Although we are unable to assess causality, our findings highlight the strength of the association between family structure and child and adolescent mental health. They also stress the need for programs to support children, parents, and families in non-traditional family types to reduce mental health inequalities in childhood and later life.

Secondhand Smoke Exposure and Low Blood Lead Levels in Association With Attention-Deficit Hyperactivity Disorder and Its Symptom Domain in Children: A Community-Based Case-Control Study

AIM

Secondhand smoke (SHS) is a major indoor pollutant. We examined the possible association between exposure to both SHS and low levels of lead and attention-deficit-hyperactivity disorder (ADHD) and its symptom domain in children.

METHODS

This case-control study was based on the results of a community survey using the ADHD rating scale conducted in 49 elementary schools. Both cases and control subjects were confirmed by a child psychiatrist. Each case was matched with one control subject according to gender, school, and grade in school. Using a multivariate conditional logistic regression model, we analyzed 214 case-control pairs of children who ranged in age from 6 to 10 years. Urine and blood levels of cotinine and of lead were determined, and information pertaining to SHS exposure was obtained by means of a questionnaire.

RESULTS

Exposure to low levels of lead (geometric mean = 1.65 µg/dL) was related to ADHD, particularly inattention (odds ratio [OR] = 1.67, 95% confidence interval [CI] = 1.07-2.59), whereas SHS exposure was associated mainly with hyperactivity/impulsivity (OR = 3.85, 95% CI = 1.55-9.56). In the pathway from blood lead to hyperactivity/impulsivity, children's SHS exposure mediated and indirectly accounted for about 73% of this relationship. The combined exposure to lead and SHS synergistically increased the risk of ADHD, evident as both inattention and hyperactivity/impulsivity.

CONCLUSION

SHS, which is associated with hyperactivity/impulsivity in particular, combined with exposure to low blood levels of lead synergistically increased the risk of ADHD. Therefore, the exposure of children to both SHS and lead needs to be reduced.

IMPLICATIONS

Although exposure to low levels of lead has been shown to be associated with ADHD, there is little evidence of symptom domain specificity. In our study, low blood lead levels were related to inattention. In addition, prenatal or postnatal exposure to SHS increased the risk of ADHD, particularly hyperactivity/impulsivity. Combined exposure to lead and SHS synergistically increased the risk for both these ADHD symptom domains. To protect children from environmental risk factors related to ADHD, it is necessary to further reduce children's exposure to SHS and lead, even in those with low blood lead levels.

Child Abuse and Mental Disorders in Iranian Adolescents

Background

Child abuse is a serious social health problem all over the world with important adverse effects.

Objectives

The aim of this study was to extend our understanding of the relation between mental disorders and child abuse.

Materials and Methods

The study was designed as a cross-sectional survey on 700 students in secondary schools using multiple cluster sampling in Yazd, Iran in 2013. We applied 2 self reported questionnaires: DASS (depression anxiety stress scales)-42 for assessing mental disorders (anxiety, stress and depression) and a standard self-reported valid and reliable questionnaire for recording child abuse information in neglect, psychological, physical and sexual domains. The collected data was analyzed using SPSS software. P-values < 0.05 were considered as significant.

Results

There was a statically significant correlation between mental disorder and child abuse score (Spearman rho: 0.2; P-value < 0.001). The highest correlations between mental disorders and child abuse were found in psychological domain, Spearman’s rho coefficients were 0.46, 0.41 and 0.36 for depression, anxiety and stress respectively (P-value < 0.001). Based on the results of logistic regression for mental disorder, females, last born adolescents and subjects with drug or alcohol abuser parents had mental disorder odds of 3, 0.4 and 1.9 times compared to others; and severe psychological abuse, being severely neglected and having sexual abuse had odds 90, 1.6 and 1.5 respectively in another model.

Conclusions

Programming for mandatory reporting of child abuse by physicians and all health care givers e.g. those attending schools or health centers, in order to prevent or reduce its detrimental effects is useful and success in preventing child abuse could lead to reductions in the prevalence of mental disorders.

Obstetric and Neonatal Adversities, Parity, and Tourette Syndrome: A Nationwide Registry

OBJECTIVE

To determine the relationships between parity, obstetric adversities, neonatal factors, and Tourette syndrome in a large nationwide cohort.

STUDY DESIGN

This nationwide, register-based, nested case-control study identified all children diagnosed with Tourette syndrome born between 1991 and 2010 from the Finnish Hospital Discharge Register (n = 767). Each case was matched to 4 controls. Information on parity, obstetric, and neonatal factors was obtained from the Finnish Medical Birth Register. Conditional logistic regression was used to determine the relationship between parity, obstetric, and neonatal factors, and Tourette syndrome.

RESULTS

Nulliparity was associated with increased odds for Tourette syndrome (OR 1.7, 95% CI 1.4-2.2), and 3 or more previous births was associated with decreased odds for Tourette syndrome (OR 0.5, 95% CI 0.3-0.9) compared with parity 1-2. Birth weight 4000-4499 g was associated with decreased odds for Tourette syndrome (OR 0.7, 95% CI 0.5-0.9). Low birth weight, gestational age, weight for gestational age, Apgar score at 1 minute, induced labor, birth type or presentation, neonatal treatment, or maternal blood pressure were not associated with Tourette syndrome.

CONCLUSIONS

Increasing parity and high birth weight are associated with decreased odds for Tourette syndrome.

Blood lead, parental marital status and the risk of attention-deficit/hyperactivity disorder in elementary school children: A longitudinal study

The aim of this study was to investigate the blood lead level and parental marital status that might influence the development of attention-deficit/hyperactivity disorder (ADHD) symptoms in school-aged children. The participants in the survey included elementary school children, and they were followed up biennially. The participants' parents or caregivers were administered a questionnaire including ADHD rating scale. Among 2967 who were not suspected to have ADHD at baseline survey, 2195 children who took follow-up test for ADHD were evaluated. The incidence rate of suspected ADHD was 5.0% (107 cases) during the two years of the follow-up period. The geometric mean blood lead level was 1.56μg/dL. Relative risk ratio for ADHD was estimated using logistic regression analysis. After adjustment for potential confounders, ADHD developed more frequently in children with blood lead levels of >2.17μg/dL (highest quartile) (RR 1.552, 95% CI 1.002-2.403) and in children with a single parent (RR 1.805, 95% CI 1.002-3.254). The RR was 3.567 (95% CI 1.595-7.980) in children with relatively high blood lead levels (>2.17μg/dL) from single-parent families, compared with those with low blood lead and a two-parent family. The ADHD risk in association with blood lead level was modified by family status.

Preterm Birth and Poor Fetal Growth as Risk Factors of Attention-Deficit/ Hyperactivity Disorder

BACKGROUND

Previous studies have shown an association between prematurity and attention- abstract deficit/hyperactivity disorder (ADHD). Results concerning late preterm infants are controversial, and studies examining fetal growth represented by weight for gestational age are scarce. Our objective was to examine the association between gestational age by each week of fetal maturity, weight for gestational age, and ADHD.

METHODS

In this population-based study, 10 321 patients with ADHD, diagnosed according to the International Classification of Diseases and 38 355 controls individually matched for gender, date and place of birth, were identified from Finnish nationwide registers. Perinatal data were obtained from the Finnish Medical Birth Register. Conditional logistic regression was used to examine the association between gestational age, weight for gestational age, and ADHD after controlling for confounding factors.

RESULTS

The risk of ADHD increased by each declining week of gestation. The associations were robust after adjusting for confounders. An elevated risk also was seen among late preterm and early term infants. As for fetal growth, the odds ratio showed a U-shaped curve with an increased risk seen when the weight for gestational age was 1 SD below and 2 SD above the mean.

CONCLUSIONS

Our findings suggest that each gestational week has significance for child's subsequent neurodevelopment and risk for ADHD. We also showed that poor fetal growth increased the risk of ADHD. This highlights the importance of taking into account both prematurity and poor fetal growth when planning the timing of birth as well as later follow-up and support policies.

The contribution of different forms of violence exposure to internalizing and externalizing symptoms among young South African adolescents

While many youth are exposed to multiple forms of co-occurring violence, the comparative impact of different forms of violence on the mental health of children and adolescents has not been clearly established. Studies from low and middle income countries in particular are lacking. The present study examined the contribution of different forms of violence to internalizing and externalizing symptoms among young adolescents in South Africa. A community-based sample of 616 high school learners completed self-report scales assessing exposure to six different forms of violence and the severity of depression, aggression and conduct disorder symptoms. In bivariate analyses, all six forms of violence were significantly associated with internalizing and externalizing difficulties. When the contribution of all forms of violence to mental health outcomes was examined simultaneously, domestic victimization emerged as the strongest predictor of both internalizing and externalizing difficulties. Cumulative exposure to other forms of violence contributed further to the prediction of aggression and conduct disorder, but not depression. Recommendations for future research, and the implications of the findings for prioritizing the development of violence prevention and intervention initiatives in the South African context, are considered.

Parental age and the risk of attention-deficit/hyperactivity disorder: a nationwide, population-based cohort study

OBJECTIVE

An increasing number of studies has shown an association between parental age and psychiatric disorders. However, there are inconsistent results regarding whether age at parenthood is associated with attention-deficit/hyperactivity disorder (ADHD). The aim of this study is to examine whether low or advanced parental age is associated with ADHD.

METHOD

In this nested case-control study, we identified 10,409 individuals with ADHD born in Finland during 1991 to 2005 and diagnosed with ADHD between 1995 and 2011, along with 39,125 controls matched on sex, date, and place of birth, from nationwide population-based registers. Conditional logistic regression was used to examine the association between parental age and ADHD in offspring, adjusting for potential confounding due to parental psychiatric history, maternal socioeconomic status, marital status, maternal smoking during pregnancy, number of previous births, and birth weight for gestational age.

RESULTS

Fathers younger than 20 years had a 1.5-fold (odds ratio [OR] = 1.55, 95% CI = 1.11-2.18, p = .01) increased risk of having offspring with ADHD as compared to fathers aged 25 to 29 years. Mothers of the same age group had a 1.4-fold (OR = 1.41, 95% CI = 1.15-1.72, p =.0009) increased risk. Advanced maternal age was inversely associated with ADHD (OR = 0.79, 95% CI = 0.64-0.97, p = .02).

CONCLUSION

ADHD was associated with young fathers or mothers at the time of birth. Health professionals working with young parents should be aware of the increased risk of ADHD in offspring. This will improve early detection; however, for the development of preventive measures and appropriate interventions, more information on the developmental pathways is needed.

Fetal exposure to perfluorinated compounds and attention deficit hyperactivity disorder in childhood

Background

The association between exposure to perfluorinated compounds (PFCs) and attention deficit hyperactivity disorder (ADHD) diagnosis has been sparsely investigated in humans and the findings are inconsistent.

Objectives

A matched case-control study was conducted to investigate the association between fetal exposure to PFCs and ADHD diagnosis in childhood.

Methods

The study base comprised children born in Malmö, Sweden, between 1978 and 2000 that were followed up until 2005. Children with ADHD (n = 206) were identified at the Department of Child and Adolescent Psychiatry. Controls (n = 206) were selected from the study base and were matched for year of birth and maternal country of birth. PFC concentrations were measured in umbilical cord serum samples. The differences of the PFC concentrations between cases and controls were investigated using Wilcoxon's paired test. Possible threshold effects (above the upper quartile for perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) and above limit of detection [LOD] for perfluorononanoic acid (PFNA)) were evaluated by conditional logistic regression.

Results

The median umbilical cord serum concentrations of PFOS were 6.92 ng/ml in the cases and 6.77 ng/ml in the controls. The corresponding concentrations of PFOA were 1.80 and 1.83 ng/ml. No associations between PFCs and ADHD were observed. Odds ratios adjusted for smoking status, parity, and gestational age were 0.81 (95% confidence interval [CI] 0.50 to 1.32) for PFOS, 1.07 (95% CI 0.67 to 1.7) for PFOA, and 1.1 (95% CI 0.75 to 1.7) for PFNA.

Conclusions

The current study revealed no support for an association between fetal exposure to PFOS, PFOA, or PFNA and ADHD.

Low birth-weight and risk for major depression: a community-based longitudinal study

The current study examines the association between low birth weight and risk for major depression from early adolescence to early adulthood. It accounts for eight documented confounders, and depression within families. Data were analyzed from the National Longitudinal Survey of Youth 1979 on mothers and offspring. Major depression was assessed with the Center for Epidemiologic Studies Depression Scale Short-Form (CES-D-SF) among offspring (N=3398) biannually, from 2000 to 2010 (aged 14-25). Competing models were examined with survival analysis and Generalized Estimated Equations (GEE). CES-D-SF based major depression was reported by 33.46% (n=1137) of participants. Among persons with very low birth weight (<1500 g), 47.5% (n=19/40) were classified with CES-D-SF depression (OR=1.81, 95% CI=0.97, 3.39). Similar results were found with survival analysis (HR=1.97, 95% CI=0.97, 4.01). Among multiple offspring families, GEE modeling showed a similar trend. On aggregate (unadjusted OR=2.46, 95% CI=1.07, 5.63; adjusted OR=2.43, 95% CI=0.94, 6.23), and within families of mothers with CES-D-SF depression (unadjusted OR=2.54, 95% CI=0.55, 11.66; adjusted OR=1.79, 95% CI=0.28, 11.42). Compelling evidence is lacking in favor of an association between very low birth weight (<1500 g), and suspected major depression from early adolescence to early adulthood after accounting for documented confounders.