Disentangling the interplay between genes, cognitive skills, and educational level in adolescent and young adult smoking - The TRAILS study.

Recent studies suggest that smoking and lower educational attainment may have genetic influences in common. However, little is known about the mechanisms through which genetics contributes to educational inequalities in adolescent and young adult smoking. Common genetic liabilities may underlie cognitive skills associated with both smoking and education, such as IQ and effortful control, in line with indirect health-related selection explanations. Additionally, by affecting cognitive skills, genes may predict educational trajectories and hereby adolescents' social context, which may be associated with smoking, consistent with social causation explanations. Using data from the Dutch TRAILS Study (N = 1581), we estimated the extent to which polygenic scores (PGSs) for ever smoking regularly (PGSSMOK) and years of education (PGSEDU) predict IQ and effortful control, measured around age 11, and whether these cognitive skills then act as shared predictors of smoking and educational level around age 16, 19, 22, and 26. Second, we assessed if educational level mediated associations between PGSs and smoking. Both PGSs were associated with lower effortful control, and PGSEDU also with lower IQ. Lower IQ and effortful control, in turn, predicted having a lower educational level. However, neither of these cognitive skills were directly associated with smoking behaviour after controlling for covariates and PGSs. This suggests that IQ and effortful control are not shared predictors of smoking and education (i.e., no indirect health-related selection related to cognitive skills). Instead, PGSSMOK and PGSEDU, partly through their associations with lower cognitive skills, predicted selection into a lower educational track, which in turn was associated with more smoking, in line with social causation explanations. Our findings suggest that educational differences in the social context contribute to associations between genetic liabilities and educational inequalities in smoking.

Educational level, attention problems, and externalizing behaviour in adolescence and early adulthood: the role of social causation and health-related selection-the TRAILS study.

Social causation and health-related selection may contribute to educational differences in adolescents' attention problems and externalizing behaviour. The social causation hypothesis posits that the social environment influences adolescents' mental health. Conversely, the health-related selection hypothesis proposes that poor mental health predicts lower educational attainment. From past studies it is unclear which of these mechanisms predominates, as attention problems and externalizing behaviour have the potential to interfere with educational attainment, but may also be affected by differences in the educational context. Furthermore, educational gradients in mental health may reflect the impact of 'third variables' already present in childhood, such as parental socioeconomic status (SES), and IQ. We investigated both hypotheses in relation to educational differences in externalizing behaviour and attention problems throughout adolescence and young adulthood. We used data from a Dutch cohort (TRAILS Study; n = 2229), including five measurements of educational level, externalizing behaviour, and attention problems from around age 14-26 years. First, we evaluated the directionality in longitudinal associations between education, externalizing behaviour, and attention problems with and without adjusting for individual differences using fixed effects. Second, we assessed the role of IQ and parental SES in relation to attention problems, externalizing behaviour, and educational level. Attention problems predicted decreases in education throughout all of adolescence and young adulthood. Differences in parental SES contributed to increases in externalizing behaviour amongst the lower educational tracks in mid-adolescence. Childhood IQ and parental SES strongly predicted education around age 14. Parental SES, but not IQ, also predicted early adolescent attention problems and externalizing behaviour. Our results provide support for the health-related selection hypothesis in relation to attention problems and educational attainment. Further, our results highlight the role of social causation from parental SES in determining adolescent educational level, attention problems, and externalizing behaviour.

Socioeconomic inequalities in adolescent health behaviours across 32 different countries - The role of country-level social mobility.

Higher family affluence is associated with healthier behaviours in adolescents, but the strength of this association varies across countries. Differences in social mobility at the country-level, i.e. the extent to which adolescents develop a different socioeconomic status (SES) than their parents, may partially explain why the association between family affluence and adolescent health behaviours is stronger in some countries than in others. Using data from adolescents aged 11-15 years from 32 countries, participating in the 2017/2018 wave of the Health Behaviour in School-aged Children (HBSC) study (N = 185,086), we employed multilevel regression models with cross-level interactions to examine whether country-level social mobility moderates the association between family affluence and adolescent health behaviours (i.e. moderate-to-vigorous physical activity, vigorous physical activity, healthy and unhealthy foods consumption, having breakfast regularly, and weekly smoking). Higher family affluence was more strongly associated with higher levels of adolescent physical activity in countries characterized by high levels of social mobility. No cross-level interactions were found for any of the other health behaviours. Differences in social mobility at the country-level may contribute to cross-national variations in socioeconomic inequalities in adolescent physical activity. Further research can shed light on the mechanisms linking country-level social mobility to inequalities in adolescent physical activity to identify targets for policy and interventions.

Evaluation of inequality constrained hypotheses using a generalization of the AIC.

In the social and behavioral sciences, it is often not interesting to evaluate the null hypothesis by means of a p-value. Researchers are often more interested in quantifying the evidence in the data (as opposed to using p-values) with respect to their own expectations represented by equality and/or inequality constrained hypotheses (as opposed to the null hypothesis). This article proposes an Akaike-type information criterion (AIC; Akaike, 1973, 1974) called the generalized order-restricted information criterion approximation (GORICA) that evaluates (in)equality constrained hypotheses under a very broad range of statistical models. The results of five simulation studies provide empirical evidence showing that the performance of the GORICA on selecting the best hypothesis out of a set of (in)equality constrained hypotheses is convincing. To illustrate the use of the GORICA, the expectations of researchers are investigated in a logistic regression, multilevel regression, and structural equation model. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Sleep characteristics across the lifespan in 1.1 million people from the Netherlands, United Kingdom and United States: a systematic review and meta-analysis.

We aimed to obtain reliable reference charts for sleep duration, estimate the prevalence of sleep complaints across the lifespan and identify risk indicators of poor sleep. Studies were identified through systematic literature search in Embase, Medline and Web of Science (9 August 2019) and through personal contacts. Eligible studies had to be published between 2000 and 2017 with data on sleep assessed with questionnaires including ≥100 participants from the general population. We assembled individual participant data from 200,358 people (aged 1-100 years, 55% female) from 36 studies from the Netherlands, 471,759 people (40-69 years, 55.5% female) from the United Kingdom and 409,617 people (≥18 years, 55.8% female) from the United States. One in four people slept less than age-specific recommendations, but only 5.8% slept outside of the 'acceptable' sleep duration. Among teenagers, 51.5% reported total sleep times (TST) of less than the recommended 8-10 h and 18% report daytime sleepiness. In adults (≥18 years), poor sleep quality (13.3%) and insomnia symptoms (9.6-19.4%) were more prevalent than short sleep duration (6.5% with TST < 6 h). Insomnia symptoms were most frequent in people spending ≥9 h in bed, whereas poor sleep quality was more frequent in those spending <6 h in bed. TST was similar across countries, but insomnia symptoms were 1.5-2.9 times higher in the United States. Women (≥41 years) reported sleeping shorter times or slightly less efficiently than men, whereas with actigraphy they were estimated to sleep longer and more efficiently than man. This study provides age- and sex-specific population reference charts for sleep duration and efficiency which can help guide personalized advice on sleep length and preventive practices.

Editorial: Something special - the scientific challenges of rare risks.

Globalization has sparked international collaboration in our field, and this trend is expected to continue in the years to come. This offers excellent opportunities to learn more about the influence of children's sociocultural environments on their development and mental health. A particular challenge when studying risk factors across cultures and populations is that the risk associated with a particular exposure may depend on its prevalence: rarity tends to aggravate impact. This phenomenon complicates not only comparisons across cultures, but also those across subpopulations and time periods within a population. Moreover, it may counteract the effectiveness of risk-reducing public health efforts. On the bright side, the extent to which the impact of a risk factor is determined by its rarity provides researchers with valuable tools to deepen and sharpen theories about the nature and working mechanisms of that risk factor, with prevention and treatment strategies that also benefit youth in exceptional conditions as a likely consequence.

Measurement and genetic architecture of lifetime depression in the Netherlands as assessed by LIDAS (Lifetime Depression Assessment Self-report).

BACKGROUND: Major depressive disorder (MDD) is a common mood disorder, with a heritability of around 34%. Molecular genetic studies made significant progress and identified genetic markers associated with the risk of MDD; however, progress is slowed down by substantial heterogeneity as MDD is assessed differently across international cohorts. Here, we used a standardized online approach to measure MDD in multiple cohorts in the Netherlands and evaluated whether this approach can be used in epidemiological and genetic association studies of depression. METHODS: Within the Biobank Netherlands Internet Collaboration (BIONIC) project, we collected MDD data in eight cohorts involving 31 936 participants, using the online Lifetime Depression Assessment Self-report (LIDAS), and estimated the prevalence of current and lifetime MDD in 22 623 unrelated individuals. In a large Netherlands Twin Register (NTR) twin-family dataset (n ≈ 18 000), we estimated the heritability of MDD, and the prediction of MDD in a subset (n = 4782) through Polygenic Risk Score (PRS). RESULTS: Estimates of current and lifetime MDD prevalence were 6.7% and 18.1%, respectively, in line with population estimates based on validated psychiatric interviews. In the NTR heritability estimates were 0.34/0.30 (s.e. = 0.02/0.02) for current/lifetime MDD, respectively, showing that the LIDAS gives similar heritability rates for MDD as reported in the literature. The PRS predicted risk of MDD (OR 1.23, 95% CI 1.15-1.32, R2 = 1.47%). CONCLUSIONS: By assessing MDD status in the Netherlands using the LIDAS instrument, we were able to confirm previously reported MDD prevalence and heritability estimates, which suggests that this instrument can be used in epidemiological and genetic association studies of depression.

Parental Age and Offspring Childhood Mental Health: A Multi-Cohort, Population-Based Investigation.

To examine the contributions of maternal and paternal age on offspring externalizing and internalizing problems, this study analyzed problem behaviors at age 10-12 years from four Dutch population-based cohorts (N = 32,892) by a multiple informant design. Bayesian evidence synthesis was used to combine results across cohorts with 50% of the data analyzed for discovery and 50% for confirmation. There was evidence of a robust negative linear relation between parental age and externalizing problems as reported by parents. In teacher-reports, this relation was largely explained by parental socio-economic status. Parental age had limited to no association with internalizing problems. Thus, in this large population-based study, either a beneficial or no effect of advanced parenthood on child problem behavior was observed.

Association of Use of Oral Contraceptives With Depressive Symptoms Among Adolescents and Young Women.

Importance: Oral contraceptives have been associated with an increased risk of subsequent clinical depression in adolescents. However, the association of oral contraceptive use with concurrent depressive symptoms remains unclear. Objectives: To investigate the association between oral contraceptive use and depressive symptoms and to examine whether this association is affected by age and which specific symptoms are associated with oral contraceptive use. Design, Setting, and Participants: Data from the third to sixth wave of the prospective cohort study Tracking Adolescents' Individual Lives Survey (TRAILS), conducted from September 1, 2005, to December 31, 2016, among females aged 16 to 25 years who had filled out at least 1 and up to 4 assessments of oral contraceptive use, were used. Data analysis was performed from March 1, 2017, to May 31, 2019. Exposure: Oral contraceptive use at 16, 19, 22, and 25 years of age. Main Outcomes and Measures: Depressive symptoms were assessed by the DSM-IV-oriented affective problems scale of the Youth (aged 16 years) and Adult Self-Report (aged 19, 22, and 25 years). Results: Data from a total of 1010 girls (743-903 girls, depending on the wave) were analyzed (mean [SD] age at the first assessment of oral contraceptive use, 16.3 [0.7]; (mean [SD] age at the final assessment of oral contraceptive use, 25.6 [0.6] years). Oral contraceptive users particularly differed from nonusers at age 16 years, with nonusers having a higher mean (SD) socioeconomic status (0.17 [0.78] vs -0.15 [0.71]) and more often being virgins (424 of 533 [79.5%] vs 74 of 303 [24.4%]). Although all users combined (mean [SD] ages, 16.3 [0.7] to 25.6 [0.6] years) did not show higher depressive symptom scores compared with nonusers, adolescent users (mean [SD] age, 16.5 [0.7] years) reported higher depressive symptom scores compared with their nonusing counterparts (mean [SD] age, 16.1 [0.6] years) (mean [SD] score, 0.40 [0.30] vs 0.33 [0.30]), which persisted after adjustment for age, socioeconomic status and ethnicity (ß coefficient for interaction with age, -0.021; 95% CI, -0.038 to -0.005; P = .0096). Adolescent contraceptive users particularly reported more crying (odds ratio, 1.89; 95% CI, 1.38-2.58; P < .001), hypersomnia (odds ratio, 1.68; 95% CI, 1.14-2.48; P = .006), and more eating problems (odds ratio, 1.54; 95% CI, 1.13-2.10; P = .009) than nonusers. Conclusions and Relevance: Although oral contraceptive use showed no association with depressive symptoms when all age groups were combined, 16-year-old girls reported higher depressive symptom scores when using oral contraceptives. Monitoring depressive symptoms in adolescents who are using oral contraceptives is important, as the use of oral contraceptives may affect their quality of life and put them at risk for nonadherence.

Assessment and characterization of phenotypic heterogeneity of anxiety disorders across five large cohorts.

To achieve sample sizes necessary for effectively conducting genome-wide association studies (GWASs), researchers often combine data from samples possessing multiple potential sources of heterogeneity. This is particularly relevant for psychiatric disorders, where symptom self-report, differing assessment instruments, and diagnostic comorbidity complicates the phenotypes and contribute to difficulties with detecting and replicating genetic association signals. We investigated sources of heterogeneity of anxiety disorders (ADs) across five large cohorts used in a GWAS meta-analysis project using a dimensional structural modeling approach including confirmatory factor analyses (CFAs) and measurement invariance (MI) testing. CFA indicated a single-factor model provided the best fit in each sample with the same pattern of factor loadings. MI testing indicated degrees of failure of metric and scalar invariance which depended on the inclusion of the effects of sex and age in the model. This is the first study to examine the phenotypic structure of psychiatric disorder phenotypes simultaneously across multiple, large cohorts used for GWAS. The analyses provide evidence for higher order invariance but possible break-down at more detailed levels that can be subtly influenced by included covariates, suggesting caution when combining such data. These methods have significance for large-scale collaborative studies that draw on multiple, potentially heterogeneous datasets. Copyright © 2016 John Wiley & Sons, Ltd.

Disparities in Depressive Symptoms Between Heterosexual and Lesbian, Gay, and Bisexual Youth in a Dutch Cohort: The TRAILS Study.

Lesbian, gay, and bisexual (LGB) youth experience elevated levels of depressive symptoms compared to heterosexual youth. This study examined how differences in depressive symptoms between heterosexual and LGB youth developed from late childhood to early adulthood. The association between sexual orientation and depressive symptoms was estimated from age 11 to 22 using data from the TRacking Adolescents' Individual Lives Survey, a longitudinal Dutch cohort study. Of the 1738 respondents (54.8 % girls) that provided information on sexual orientation, 151 self-identified as LGB. In line with the Minority Stress Framework, it was tested whether self-reported peer victimization and parental rejection mediated the association between sexual orientation and depressive symptoms. Results indicated that LB girls and bisexuals were at increased risk of depressive symptoms already at age 11. The difference increased over time and was related to pubertal development in girls and bisexual individuals. Furthermore, self-reported peer victimization (for both boys and girls), as well as parental rejection (for girls/bisexuals), mediated the association between sexual orientation and depressive symptoms. The authors conclude that already in late childhood, associations between sexual orientation and depressive symptoms are found, partly due to minority stress mechanisms.

Cohort Profile Update: the TRacking Adolescents' Individual Lives Survey (TRAILS).

TRAILS consists of a population cohort (N=2230) and a clinical cohort (N=543), both of which were followed from about age 11 years onwards. To date, the population cohort has been assessed five times over a period of 11 years, with retention rates ranging between 80% and 96%. The clinical cohort has been assessed four times over a period of 8 years, with retention rates ranging between 77% and 85%. Since the IJE published a cohort profile on the TRAILS in 2008, the participants have matured from adolescents into young adults. The focus shifted from parents and school to entry into the labour market and family formation, including offspring. Furthermore, psychiatric diagnostic interviews were administered, the database was linked to a Psychiatric Case Registry, and the availability of genome-wide SNP variations opened the door to genome-wide association studies regarding a wide range of (endo)phenotypes. With some delay, TRAILS data are available to researchers outside the TRAILS consortium without costs; access can be obtained by submitting a publication proposal (see www.trails.nl).

Socioeconomic position predicts specialty mental health service use independent of clinical severity: the TRAILS study.

OBJECTIVE: To investigate associations between different indices of family socioeconomic position (SEP) and the use of specialty mental health services (SMHS) and whether the associations exist after adjusting for severity of mental problems. METHOD: Using data from a large longitudinal study of adolescents (N = 2,149; mean age = 13.6 years [SD = 0.53, range = 12 to 15 years]; 51% girls), we assessed the relations of family SEP indices with SMHS use while accounting for severity of mental problems in logistic regression models. Multiple informants (parent, self, and teachers) assessed severity of mental health problems using the Achenbach scales. A parent questionnaire was used to assess family SEP (parents' education, parents' occupation, and family income) and SMHS use. Baseline response rate was 76%, and 96.4% of responders were reassessed at a 2.5-year follow-up visit. Baseline assessments ran from March 2001 through July 2002 and follow-up from September 2003 to December 2004. RESULTS: Overall, 6.7% of the total sample and 42.9% of those with mental problems accessed SMHS. Univariable analyses yielded no significant associations between SMHS and all the indices of SEP. Adjustment for the severity of mental problems resulted in substantial and statistically significant associations of indices of SEP with SMHS use. Adolescents were particularly more likely to use SMHS with increasing levels of maternal education. Compared to mothers with elementary education, those with university education were three times more likely to consult SMHS independent of severity of their offspring's mental health problems (odds ratio [OR] = 3.18, confidence interval [CI] = 1.22, 8.30). For the aggregate measure of SEP, high SEP was associated with increased use of SMHS compared with low SEP (OR = 1.63, CI = 1.04, 2.55). CONCLUSIONS: Higher levels of maternal education and overall SEP predict more SMHS use when the severity of mental problems was accounted for. Without correcting for the severity of mental problems, the true association between SEP and SMHS use is obscured in early adolescents.

Cognitive ability, parental socioeconomic position and internalising and externalising problems in adolescence: findings from two European cohort studies.

We investigated whether cognitive ability (CA) may be a moderator of the relationship of parental socioeconomic position (SEP) with internalising and externalising problems in adolescents. We used data from two longitudinal cohort studies; the Avon Longitudinal Study of Parents and Children (ALSPAC) and the Tracking Adolescents' Individual Lives Survey (TRAILS). Indicators of SEP were mother's education and household income. CA was estimated with IQ scores, derived from the Wechsler Intelligence Scale for Children. Internalising and externalising problems were measured with the Strengths and Difficulties Questionnaire in ALSPAC and with the Child Behavior Checklist in TRAILS. Logistic regression analyses were used to estimate the relative index of inequality (RII) for each outcome; the RII provides the odds ratio comparing the most to least deprived for each measure of SEP. In fully adjusted models an association of mother's education with externalising problems was observed [ALSPAC RII 1.42 (95%CI: 1.01-1.99); TRAILS RII 2.21 (95%CI: 1.37-3.54)], and of household income with internalising and externalising problems [pooled ALSPAC & TRAILS internalising RII 1.30 (95%CI: 0.99-1.71); pooled ALSPAC & TRAILS externalising RII 1.38 (95%CI: 1.03-1.84)]. No consistent associations were observed between mother's education and internalising problems. Results of stratified analyses and interaction-terms showed no evidence that CA moderated the association of SEP with internalising or externalising problems.

Life stressors as mediators of the relation between socioeconomic position and mental health problems in early adolescence: the TRAILS study.

OBJECTIVE: Life stressors and family socioeconomic position have often been associated with mental health status. The aim of the present study is to contribute to the understanding of the pathways from low socioeconomic position and life stressors to mental problems. METHOD: In a cross-sectional analysis using data from a longitudinal study of early adolescents (N = 2,149, 51% girls; mean age 13.6 years, SD 0.53, range 12-15), we assessed the extent of mediation of the association between family socioeconomic position and mental health problems by different types of life stressors in multiple regression models. Stressors were rated as environment related or person related. Information on socioeconomic position was obtained directly from parents, and internalizing and externalizing problem behaviors were assessed by reports from multiple informants (parents, self, and teachers). RESULTS: Low socioeconomic position was associated with more mental health problems and more life stressors. Both environment-related and person-related stressors predicted mental health problems independently of socioeconomic position. The associations between socioeconomic position and all mental health outcomes were partly mediated by environment-related life stressors. Mediation by environment-related and person-related stressors as assessed by linear regression amounted to 56% (95% confidence interval [CI] 35%-78%) and 7% (95% CI -25% to 38%) for internalizing problems and 13% (95% CI 7%-19%) and 5% (95% CI -2% to 13%) for externalizing problems, respectively. CONCLUSIONS: Environment-related, but not person-related, stressors partly mediated the association between socio economic position and adolescent mental problems. The extent of mediation was larger for internalizing than for externalizing problems. Because the effect sizes of the associations were relatively small, targeted interventions to prevent impaired mental health may have only modest benefits to adolescents from low socioeconomic background.

Socioeconomic position and mental health problems in pre- and early-adolescents: the TRAILS study.

BACKGROUND: Family socioeconomic position (SEP) is known to be associated with adolescent mental health. Whether the relationship is different for different mental health dimensions is unknown. METHODS: Using a cross-sectional design, we investigated the differential effects of family SEP on multiple mental health dimensions in preadolescents (N = 2230, baseline age 10-12, 49% boys) using reports from multiple informants (parent, self, and teachers). A score equal to or higher than the 85th percentile (averaged across informants) defined mental health problems. RESULTS: SEP was inversely associated with all dimensions. Compared to high SEP, the odds ratios (OR) for externalizing problems were 3.88 (95% confidence interval (CI): 2.56, 5.90) and 2.05 (CI: 1.34, 3.14) for low and intermediate SEP, respectively. For internalizing problems, they were 1.86 (CI: 1.28, 2.70) and 1.37 (CI: 0.94, 2.00), respectively. When adjusted for externalizing problems, SEP effects on internalizing problems materially attenuated (OR: 1.47, CI: 0.78, 1.68 and OR: 1.34, CI: 0.91, 1.96) while the converse was less pronounced (OR: 3.39, CI: 2.24, 5.15) and (OR: 1.91, CI: 1.25, 2.94). CONCLUSION: In early adolescence, the risk of mental health problems increases with decreasing SEP, particularly for externalizing problems. Further, the SEP-internalizing problems relationship is partly explained by shared aspects with externalizing problems.