Hair steroid before and after COVID-19 in preschoolers: the moderation of family characteristics.

BACKGROUND: Frequent or prolonged exposure to stressors may jeopardize young children's health. The onset of the COVID-19 pandemic, coupled with disruptions in daily routines and social isolation resulting from public health preventive measures, have raised concerns about its potential impact on children' experienced stress, particularly for young children and vulnerable families. However, whether the pandemic was accompanied by changes in physiological stress remains unknown as perceived stress is not a good proxy of physiological stress. This study examined if preschoolers showed increasing hair steroid concentrations following the onset of the COVID-19 pandemic and whether family characteristics may have exacerbated or buffered these changes. METHODS: 136 preschoolers (2-4 years) provided hair for steroid measurement (cortisol, dehydroepiandrosterone (DHEA), cortisone, cortisol-to-DHEA ratio, cortisol-to-cortisone ratio) in October-November 2019 (T0) and in July-August 2020 (T1). A 2-centimeter hair segment was analyzed, reflecting steroid production over the two months leading up to collection. Family income, conflict resolution and lack of cohesion, as well as parents' COVID-19 stress were reported by parents. Linear mixed models for repeated measures and Bayes factors were used. RESULTS: No significant changes were noted from before to after the onset of the COVID-19 pandemic for most hair steroids. However, a moderating role of family conflict resolution was noted. Children living with parents with a better ability to resolve conflicts had lower levels of DHEA compared to those who had more difficulty managing conflicts. Additionally, lower levels of family cohesion and income were linked to some steroids, especially DHEA, suggesting that these factors may relate to children's physiological stress. Finally, boys had higher DHEA levels than girls. CONCLUSION: Our findings suggest that stress biomarkers were comparable from before to during the COVID-19 pandemic. This observation holds true despite the pandemic being perceived by many as a novel, unpredictable, and potentially threatening event. Findings further suggest that family characteristics are associated with hair steroid, especially DHEA, which deserves further investigation.

Trajectories of Adolescent Media Use and Their Associations With Psychotic Experiences.

Importance: Adolescent media use is thought to influence mental health, but whether it is associated with psychotic experiences (PEs) is unclear. Objective: To examine longitudinal trajectories of adolescent media use and their associations with PEs at 23 years of age. Design, Setting, and Participants: This cohort study included participants from the Québec Longitudinal Study of Child Development (1998-2021): children who were born in Québec, Canada, and followed up annually or biennially from ages 5 months through 23 years. Data were analyzed between January 2023 and January 2024. Exposures: Participants reported their weekly amount of television viewing, video gaming, computer use, and reading at ages 12, 13, 15, and 17 years. Main Outcome and Measures: Lifetime occurrence of PEs was measured at 23 years of age. Covariables included sociodemographic, genetic, family, and childhood characteristics between ages 5 months and 12 years. Results: A total of 1226 participants were included in the analyses (713 [58.2%] female, 513 [41.8%] male). For each media type, latent class mixed modeling identified 3 group-based trajectories, with subgroups following trajectories of higher use: television viewing, 128 (10.4%); video gaming, 145 (11.8%); computer use, 353 (28.8%); and reading, 140 (11.4%). Relative to lower video gaming, higher video gaming was preceded by higher levels of mental health and interpersonal problems at age 12 years. Adjusting for these risk factors mitigated the association between higher video gaming and PEs at age 23 years. The curved trajectory of computer use (189 [15.4%] participants), characterized by increasing levels of use until age 15 years followed by a decrease, was associated with higher PEs (estimated difference, +5.3%; 95% CI, +1.5% to +9.3%) relative to lower use (684 [55.8%] participants). This association remained statistically significant after covariable adjustment. Conclusions and Relevance: This study found that longitudinal trajectories of media use during adolescence were modestly associated with PEs at age 23 years, likely reflecting the influence of shared risk factors. Understanding the environmental determinants and psychosocial functions of media use during adolescence may help better integrate digital technologies in the prevention and management of PEs.

Hair cortisol stability after 5-year storage: Insights from a sample of 17-year-old adolescents.

Background: Hair has become an increasingly valuable medium to investigate the association between chronic stress, stable differences in systemic cortisol secretion and later health. Assessing cortisol in hair has many advantages, notably its non-invasive and retrospective nature, the need for a single biospecimen and convenient storage until analysis. However, few studies offered empirical evidence documenting the long-term temporal stability of hair cortisol concentration (HCC) prior to analysis, especially in humans. Yet, knowing how long hair samples can be stored without compromising the accuracy of cortisol measurement is of crucial importance when planning data collection and analysis. This study examined the stability of HCC in hair samples assayed twice, five years apart. Methods: We randomly selected from a larger distribution of HCC measured in 17-year-old participants 39 hair samples to be reanalyzed five years later, under the same general conditions. Samples were assayed in duplicate using a luminescence immunoassay and compared with the original HCC using the Lin's concordance correlation coefficient (CCC), Bland-Altman plot analysis and Wilcoxon rank test. Results: Findings indicated a good concordance and temporal stability between the two samples assayed five years apart (CCC [95% confidence interval] = 0.84 [0.72-0.91]), although a small decrease in HCC was noted 5 years later (8.4% reduction, p = 0.001). Conclusion: Our study confirms that hair samples, when stored at room temperature and away from sunlight, can be assayed for at least five years without risking a loss of precision in HCC measurement.

Longitudinal assessment of psychological distress and its determinants in a sample of firefighters based in Montreal, Canada.

Introduction: Firefighters face elevated risks of common mental health issues, with distress rates estimated at around 30%, surpassing those of many other occupational groups. While exposure to potentially traumatic events (PTEs) is a well-recognized risk factor, existing research acknowledges the need for a broader perspective encompassing multidimensional factors within the realm of occupational stress. Furthermore, this body of evidence heavily relies on cross-sectional studies. This study adopts an intensive longitudinal approach to assess psychological distress and its determinants among firefighters. Methods: Participants were recruited from 67 fire stations in Montreal, Canada, meeting specific criteria: full-time employment, smartphone ownership, and recent exposure to at least one PTE, or first responder status. Subjects underwent a telephone interview and were directed to use an app to report depressive, post-traumatic, and generalized anxiety symptoms every 2 weeks, along with work-related stressors, social support, and coping styles. Analyses involved 274 participants, distinguishing between those exceeding clinical thresholds in at least one distress measure (the "distressed" subgroup) and those deemed "resilient." The duration and onset of distress were computed for the distressed group, and linear mixed models were employed to evaluate determinants for each psychological distress variable. Results: Clinical psychological distress was observed in 20.7% of participants, marked by depressive, post-traumatic, and anxiety symptoms, often within the first 4-week reference period. Contextual factors (operational climate, social support, solitude) and individual factors (coping style, solitude and lifetime traumatic events in private life) exhibited more significant impacts on psychological distress than professional pressures within the firefighters' work environment. Discussion: This study reports lower rates of psychological distress than previous research, possibly attributable to sample differences. It highlights that reported symptoms often represent a combined and transient layer of distress rather than diagnosable mental disorders. Additionally, determinants analysis underscores the importance of interpersonal relationships and coping mechanisms for mental health prevention interventions within this worker group. The findings carry implications for the development of prevention and support programs for firefighters and similar emergency workers.

The Signature Biobank: A longitudinal biopsychosocial repository of psychiatric emergency patients.

The Signature Biobank is a longitudinal repository of biospecimen, psychological, sociodemographic, and diagnostic data that was created in 2012. The Signature Consortium represents a group of approximately one hundred Quebec-based transdisciplinary clinicians and research scientists with various expertise in the field of psychiatry. The objective of the Signature Biobank is to investigate the multi-faceted underpinnings of psychiatric disorders among patients in crisis. The Signature Consortium is expanding and includes new active members that seek to highlight the contributions made by Signature Biobank since its inception. This article details our research protocol, directions, and summarizes contributions. To date, we have collected biological samples (n = 1,986), and questionnaire data (n = 2,085) from psychiatric emergency patients of the Institut universitaire en santé mentale de Montréal (Quebec, Canada), with a large proportion from whom both data types were collected (n = 1,926). In addition to this, a subsample of patients was followed-up at hospital discharge, and two additional outpatient clinic appointments (n = 958 with at least one follow-up). In addition, a socio-demographically matched comparison group of individuals who were not hospitalized for psychiatric disorders (n = 149) was recruited from the surrounding catchment area. To summarize, a systematic review of the literature shows that the Signature Biobank has contributed to better characterizing psychiatric comorbidities, biological profiles, and psychosocial functioning across some of the most common psychiatric disorders, including psychosis, mood, anxiety, and substance use disorders. The Signature Biobank is now one of the world's largest repositories of data collected from patients receiving care at a psychiatric emergency unit.

Associations between digital media use and psychotic experiences in young adults of Quebec, Canada: a longitudinal study.

PURPOSE: Digital media use has been associated with psychotic experiences in youth from the community, but the direction of association remains unclear. We aimed to examine between- and within-person associations of digital media use and psychotic experiences in youth. METHODS: The sample included 425 participants aged 18-25 years (82.5% female) from the community, followed between May 2021 and January 2022 over 3 time points-of which 263 participants (61.9%) completed at least 2. Digital media use was self-reported as time spent daily on TV and streaming platforms, social media, and video games over the past 3 months. Psychotic experiences in the past 3 months were measured with the 15-item Community Assessment of Psychic Experiences. Associations between digital media use and psychotic experiences were estimated using a random-intercept cross-lagged panel model. RESULTS: On average, individuals who reported greater digital media use also reported higher levels of psychotic experiences (r = 0.34, 95% CI 0.15, 0.53). However, a person's variation in digital media use, relative to their personal average, was not significantly associated with subsequent variations in their levels of psychotic experiences, or vice-versa. Results were similar across TV/streaming, social media and video game use, and after adjusting for age, sex, education, sleep, physical activity, and cannabis use. CONCLUSION: Individuals with a tendency for higher levels of digital media use also had a tendency for higher levels of psychotic experiences. Understanding this association may help personalize mental health interventions for people with psychotic experiences, which may be offered digitally to promote their accessibility.

Concurrent and prospective associations between family socioeconomic status, social support and salivary diurnal and hair cortisol in adolescence.

BACKGROUND: Exposure to socioeconomic adversity is hypothesized to impact hypothalamic-pituitary-adrenal (HPA) axis activity and cortisol secretion, but existing evidence is inconsistent. Yet, few studies have investigated this association using a developmental approach that considers potential protective contextual factors. This study examined the role of stability and changes in family socioeconomic status (SES) in the prediction of multiple cortisol indicators and tested whether social support moderated these associations. METHODS: Participants were part of a population-based sample of twin pairs recruited at birth. Family SES was assessed in early childhood (ages 0-5) and mid-adolescence (age 14). Social support was assessed at ages 14 and 19. Diurnal cortisol (n = 569) was measured at age 14 at awakening, 30 min later, in the afternoon and evening over four non-consecutive days. Hair cortisol concentration (HCC, n = 704) was measured at age 19. All data were collected before the pandemic and multilevel regression models were conducted to account for the nested data structure. RESULTS: Youth exposed to lower family SES levels in childhood and mid-adolescence had a flatter diurnal slope and higher HCC compared with those who experienced upward socioeconomic mobility in mid-adolescence. Contrastingly, mid-adolescence SES showed no association with the diurnal slope or HCC for youth from higher-SES households in early childhood. Moreover, youth raised in higher-SES families in early childhood had a higher CAR in mid-adolescence if they reported greater social support in mid-adolescence. Social support also moderated the SES-cortisol association in mid-adolescence, with higher-SES youth showing higher awakening cortisol secretion when reporting more social support. CONCLUSIONS: Our findings support the hypothesis that early socioeconomic adversity sensitizes HPA axis activity to later socioeconomic disadvantage, which may bear consequences for socioemotional and behavioral functioning.

Longitudinal Associations between Prenatal Exposure to Phthalates and Steroid Hormones in Maternal Hair Samples from the SEPAGES Cohort.

We assessed phthalate-hormone associations in 382 pregnant women of the new-generation SEPAGES cohort (2014-2017, France) using improved exposure and outcome assessments. Metabolites from seven phthalate compounds and the replacement di(isononyl)cyclohexane-1,2-dicarboxylate (DINCH) were measured in within-subject pools of repeated urine samples collected at the second and third pregnancy trimesters (≈21 samples/trimester). Metabolites from five steroid hormones were measured in maternal hair samples collected at delivery, reflecting cumulative levels over the previous weeks to months. Adjusted linear regression and Bayesian weighted quantile sum (BWQS) mixture models were performed. Each doubling in third-trimester urinary mono-benzyl phthalate (MBzP) concentrations was associated with an average increase of 13.3% (95% CI: 2.65, 24.9) for ∑cortisol, 10.0% (95% CI: 0.26, 20.7) for ∑cortisone, 17.3% (95% CI: 1.67, 35.4) for 11-dehydrocorticosterone, and 16.2% (95% CI: 2.20, 32.1) for testosterone, together with a suggestive 10.5% (95% CI: -1.57, 24.1) increase in progesterone levels. Each doubling in second-trimester urinary di-isononyl phthalate (DiNP) concentrations was inversely associated with testosterone levels (-11.6%; 95% CI: -21.6, -0.31). For most hormones, a nonsignificant trend toward a positive phthalate mixture effect was observed in the third but not in the second trimester. Our study showed that exposure to some phthalate metabolites, especially MBzP, may affect adrenal and reproductive hormone levels during pregnancy.

Increased urban greenspace in childhood associated with lower inattention deficit among adolescents.

PURPOSE: There is a growing interest in assessing the benefits of exposure to urban greenspace on mental health due to the increased urbanization of youth and concerns for their mental health. We investigated the prospective associations of residential greenspace in childhood and mental health in adolescence. Use of a well-characterized birth cohort permitted adjustment for a range of potential confounding factors including family and neighborhood characteristics in addition to prior mental health problems, and exploration of moderation effects by sex and family socioeconomic status. METHODS: We analyzed longitudinal data collected from 742 urban-dwelling participants of the Quebec Longitudinal Study of Children Development. The Normalized Difference Vegetation Index (NDVI) within 250, 500, and 1000 m buffer zones surrounding the home residence was used to indicate childhood exposure to greenspace. Six self-reported mental health problems at 15/17 years were examined using the Mental Health and Social Inadaptation questionnaire: inattention, hyperactivity/impulsivity, conduct, depression, anxiety, and suicidal ideation. RESULTS: Childhood urban greenspace was associated with lower inattention problems in both females and males. We observed a 0.14 reduced standard deviation (SD) (ß = - 0.14, SE = 0.05, p < 0.01) in relation to an interquartile range (IQR) increase of NDVI (0.15) at the 250 m buffer zone, and similar results were found in 500 m and 1000 m buffer zones. These associations only slightly attenuated after adjustment for individual (sex, childhood mental health), family (family SES, maternal age at birth, parental mental health, family composition), and neighborhood (material and social deprivation) characteristics (ß = - 0.13, SE = 0.06, p = 0.03). No association was found for other mental health problems, and no moderation associations of sex or family socioeconomic status were observed. CONCLUSION:  These findings suggest that increasing residential greenspace in cities may be associated with modest benefits in attentional capacities in youth, necessitating further research to elucidate the underlying mechanisms.

Derivation of probable child maltreatment indicators using prospectively recorded information between 5 months and 17 years in a longitudinal cohort of Canadian children.

BACKGROUND: Both prospective and retrospective measures of child maltreatment predict mental and physical health problems, despite their weak concordance. Research remains largely based on retrospective reports spanning the entire childhood due to a scarcity of prospectively completed measures targeting maltreatment specifically. OBJECTIVE: We developed a prospective index of child maltreatment in the Québec Longitudinal Study of Child Development (QLSCD) using prospective information collected from ages 5 months to 17 years and examined its concordance with retrospective maltreatment. PARTICIPANTS AND SETTING: The QLSCD is an ongoing population-based cohort that includes 2,120 participants born from 1997-1998 in the Canadian Province of Quebec. METHODS: As the QLSCD did not have maltreatment as a focal variable, we screened 29,600 items completed by multiple informants (mothers, children, teachers, home observations) across 14 measurement points (5 months-17 years). Items that could reflect maltreatment were first extracted. Indicators were derived across preschool, school-age and adolescence periods and by the end of childhood and adolescence, including presence (yes/no), chronicity (re-occurrence), extent of exposure and cumulative maltreatment. Two maltreatment experts reviewed these items for inclusion and determined cut-offs for possible child maltreatment (n=251 items). Retrospective maltreatment was self-reported at 23 years. RESULTS: Across all developmental periods, the presence of maltreatment was as follows: physical abuse (16.3-21.8%), psychological abuse (3.3-21.9%), emotional neglect (20.4-21.6%), physical neglect (15.0-22.3%), supervisory neglect (25.8-44.9%), family violence (4.1-11.2%) and sexual abuse (9.5% in adolescence only). The degree of concordance between prospective and retrospective reports for each type of maltreatment was weak (.038-.110), yet significant (ps<.01), except for emotional neglect (p=.148). CONCLUSIONS: In addition to the many future research opportunities offered by these prospective indicators of maltreatment, this study offers a roadmap to researchers wishing to undertake a similar task.

Adolescent anxiety and pain problems: A joint, genome-wide investigation and pathway-based analysis.

Both common pain and anxiety problems are widespread, debilitating and often begin in childhood-adolescence. Twin studies indicate that this co-occurrence is likely due to shared elements of risk, rather than reciprocal causation. A joint genome-wide investigation and pathway/network-based analysis of adolescent anxiety and pain problems can identify genetic pathways that subserve shared etiopathogenetic mechanisms. Pathway-based analyses were performed in the independent samples of: The Quebec Newborn Twin Study (QNTS; 246 twin pairs and 321 parents), the Longitudinal Study of Child Development in Quebec (QLSCD; n = 754), and in the combined QNTS and QLSCD sample. Multiple suggestive associations (p<1×10-5), and several enriched pathways were found after FDR correction for both phenotypes in the QNTS; many nominally-significant enriched pathways overlapped between pain problems and anxiety symptoms (uncorrected p<0.05) and yielded results consistent with previous studies of pain or anxiety. The QLSCD and the combined QNTS and QLSCD sample yielded similar findings. We replicated an association between the pathway involved in the regulation of myotube differentiation (GO:0010830) and both pain and anxiety problems in the QLSDC and the combined QNTS and QLSCD sample. Although limited by sample size and thus power, these data provide an initial support to conjoint molecular investigations of adolescent pain and anxiety problems. Understanding the etiology underlying pain and anxiety co-occurrence in this age range is relevant to address the nature of comorbidity and its developmental pathways, and shape intervention. The replication across samples implies that these effects are reliable and possess external validity.

Child Sexual Abuse and Employment Earnings in Adulthood: A Prospective Canadian Cohort Study.

INTRODUCTION: Child sexual abuse remains a worldwide concern with devastating consequences on an individual's life. This longitudinal study investigates the associations between child sexual abuse (official reports versus retrospective self-reports) and subgroups by perpetrator identity (intrafamilial and extrafamilial), severity (penetration/attempted penetration, fondling/touching, noncontact), and chronicity (single, multiple episodes) and employment earnings in adulthood in a cohort followed for over 30 years. METHODS: The Quebec Longitudinal Study of Kindergarten Children database was linked to child protection services (official reports of sexual abuse) and to Canadian government tax returns (earned income). The sample included 3,020 individuals in Quebec French-language school kindergartens in 1986/1988, followed until 2017, and assessed with retrospective self-reports at age 22 years. Tobit regressions were used for associations with earnings (ages 33-37 years), adjusting for sex and family socioeconomic characteristics in 2021-2022. RESULTS: Individuals who experienced child sexual abuse had lower annual earnings. Those with retrospective self-reported sexual abuse (n=340) earned $4,031 (95% CI= -7,134, -931) less annually at ages 33-37 years than nonabused individuals (n=1,320), with pronounced differences for those with official reports (n=20), earning $16,042 (95% CI= -27,465, -4,618) less. Individuals self-reporting intrafamilial sexual abuse earned $4,696 (95% CI= -9,316, -75) less than those who experienced extrafamilial sexual abuse, whereas those self-reporting penetration/attempted penetration earned $6,188 (95% CI= -12,248, -129) less than those who experienced noncontact sexual abuse. CONCLUSIONS: Earnings gaps were highest for severest child sexual abuse (official reports, intrafamilial, penetrative). Future studies should investigate the underlying mechanisms. Improving support for victims of child sexual abuse could yield socioeconomic returns.

Association between child maltreatment and depressive symptoms in emerging adulthood: The mediating and moderating roles of DNA methylation.

Prospective studies suggest that child maltreatment substantially increases the risk for depression in adulthood. However, the mechanisms underlying this association require further elucidation. In recent years, DNA methylation has emerged as a potential mechanism by which maltreatment experiences (a) could partly explain the emergence or aggravation of depressive symptoms (i.e., mediation) and/or (b) could increase (or decrease) the risk for depressive symptoms (i.e., moderation). The present study tested whether the methylation levels of nine candidate genes mediated and/or moderated the association between maltreatment experiences in childhood and depressive symptoms in emerging adulthood. The sample comprised 156 men aged between 18 and 35 years. Maltreatment experiences and depressive symptoms were assessed retrospectively using self-reported questionnaires. Methylation levels of nine candidate genes (COMT, FKBP5, IL6, IL10, MAOA, NR3C1, OXTR, SLC6A3 and SLC6A4), previously reported to be sensitive to early-life stress, were quantified from saliva samples. Maltreatment experiences in childhood were significantly associated with depressive symptoms in emerging adulthood. Both maltreatment experiences and depressive symptoms were associated with the methylation levels of two genomic sites, which cumulatively, but not individually, explained 16% of the association between maltreatment experiences in childhood and depressive symptoms in emerging adulthood. Moreover, maltreatment experiences in childhood interacted with the methylation levels of fourteen genomic sites, which cumulatively, but not individually, modulated the level of depressive symptoms in young male adults who were maltreated as children. However, none of these effects survived multiple testing correction. These findings bring attention to the cumulative effects of DNA methylation measured in several candidate genes on the risk of reporting depressive symptoms following maltreatment experiences in childhood. Nonetheless, future studies need to clarify the robustness of these putative cumulative effects in larger samples and longitudinal cohorts.

Link Between Peer Victimization in College and Cortisol Secretion: Roles of Genetic Vulnerabilities and Social Support.

It is unclear whether peer victimization in college interacts with genetic vulnerabilities or social support in predicting cortisol secretion. This issue was addressed using a sample of 162 Monozygotic and 237 Dizygotic twin pairs (54% females; 86% Whites, 6% Blacks, 6% Asians, 0.3% Native North Americans). At age 19, participants provided hair for cortisol extraction and reported about victimization in college and support by the mother, father, and best friend. Biometric modeling revealed that environmental influences on cortisol secretion were reduced and genetic influences exacerbated when victimization was high. Moderate to high maternal support mitigated the association between victimization and high cortisol secretion. The findings suggest that victimization in college contributes to physical "wear-and-tear", which may be counteracted by social support.

Cognitive Outcomes of Children With Complex Trauma: A Systematic Review and Meta-Analyses of Longitudinal Studies.

Longitudinal studies have shown that children with complex trauma (i.e., exposure to multiple or repeated traumatic events of an interpersonal nature) have poorer cognitive outcomes later in life than children without complex trauma. This association may be moderated by the timing of the trauma, which may explain, in part, some heterogeneity in the findings reported across previous investigations. The objective of the systematic review and meta-analyses was to compare the cognitive outcomes of children with complex trauma and controls and to explore whether the timing of trauma (i.e., its onset and recency) moderated this association. Electronic databases (APA PsycNET, Pubmed Central, ERIC, CINAHL, Embase) and gray literature were systematically searched. To be included, studies had to (1) have a longitudinal design, (2) comprise children with complex trauma and controls, and (3) include a cognitive assessment. Thirteen studies were identified. Meta-analyses were conducted to compare children with complex trauma and controls, while subgroup analyses and meta-regressions explored the impact of potential moderators. Children with complex trauma had poorer overall cognitive functioning than controls, and the timing of trauma (early onset and, to a greater extent, recency of trauma) moderated this association. Thus, findings suggest that children with complex trauma are at risk of cognitive difficulties quickly after trauma exposure. As such, systematic neuropsychological assessment and interventions supporting the optimal development of cognitive functioning among children with complex trauma should be investigated to determine whether prompt interventions lead to better cognitive functioning.

The phenotypic associations and gene-environment underpinnings of socioeconomic status and diurnal cortisol secretion in adolescence.

While converging evidence suggests that both environmental and genetic factors underlie variations in diurnal cortisol, the extent to which these sources of influence vary according to socioeconomic status (SES) has seldom been investigated, particularly in adolescence. To investigate whether a distinct genetic and environmental contribution to youth's diurnal cortisol secretion emerges according to family SES and whether the timing of these experiences matters. Participants were 592 twin pairs, who mostly came from middle-income and intact families and for whom SES was measured in childhood and adolescence. Diurnal cortisol was assessed at age 14 at awakening, 30 min later, in the afternoon and evening over four nonconsecutive days. SES-cortisol phenotypic associations were specific to the adolescence period. Specifically, higher awakening cortisol levels were detected in wealthier backgrounds, whereas higher cortisol awakening response (CAR) and diurnal changes were present at both ends of the SES continuum. Moreover, smaller genetic contributions emerged for awakening cortisol in youth from poorer compared to wealthier backgrounds. The results suggest that the relative contribution of inherited factors to awakening cortisol secretion may be enhanced or suppressed depending on the socio-family context, which may help to decipher the mechanisms underlying later adjustment.

Polygenic risk for aggressive behavior from late childhood through early adulthood.

Twin studies suggest a substantial role for genes in explaining individual differences in aggressive behavior across development. It is unclear, however, how directly measured genetic risk is associated with aggressive behavior at different moments across adolescence and how genes might distinguish developmental trajectories of aggressive behavior. Here, a polygenic risk score derived from the EAGLE-Consortium genome-wide association study of aggressive behavior in children was tested as predictor of latent growth classes derived from those measures in an adolescent population (n = 2229, of which n = 1246 with genetic information) and a high-risk sample (n = 543, of which n = 335 with genetic information). In the population sample, the polygenic risk score explained variation in parent-reported aggressive behavior at all ages and distinguished between stable low aggressive behavior and moderate and high-decreasing trajectories based on parent-report. In contrast, the polygenic risk score was not associated with self- and teacher-reported aggressive behavior, and no associations were found in the high-risk sample. This pattern of results suggests that methodological choices made in genome-wide association studies impact the predictive strength of polygenic risk scores, not just with respect to power but likely also in terms of generalizability and specificity.

Association of childhood bullying victimisation with suicide deaths: findings from a 50-year nationwide cohort study.

BACKGROUND: Bullying victimisation has been associated with increased risk of suicide ideation and attempt throughout the lifespan, but no study has yet examined whether it translates to a greater risk of death by suicide. We aimed to determine the association of bullying victimisation with suicide mortality. METHODS: Participants were drawn from the 1958 British birth cohort, a prospective follow-up of all births in 1 week in Britain in 1958. We conducted logistic regressions on 14 946 participants whose mothers reported bullying victimisation at 7 and 11 years with linked information on suicide deaths through the National Health Service Central Register. RESULTS: Fifty-five participants (48 males) had died by suicide between the age 18 and 52 years. Bullying victimisation was associated with suicide mortality; a one standard deviation increases in bullying victimisation linked to an increased odds for suicide mortality [odds ratio (OR) 1.29; 1.02-1.64] during adulthood. The OR attenuated by 11% after adjustment for individual (e.g. behavioural and emotional problems) and familial characteristics (e.g. adverse childhood experiences, 1.18; 0.92-1.51). Analysis of bullying victimisation frequency categories yields similar results: compared with individuals who had not been bullied, those who had been frequently bullied had an increased odds for suicide mortality (OR 1.89; 0.99-3.62). CONCLUSION: Our study suggests that individuals who have been frequently bullied have a small increased risk of dying by suicide, when no other risk factors is considered. Suicide prevention might start in childhood, with bullying included in a range of inter-correlated vulnerabilities encompassing behavioural and emotional difficulties and adverse experiences within the family.

Polygenic risk score and peer victimisation independently predict depressive symptoms in adolescence: results from the Quebec Longitudinal Study of Children Development.

BACKGROUND: Peer victimisation has been associated with depressive symptoms during adolescence, however not all peer victimised adolescents will exhibit such symptoms. This study tested whether having a genetic predisposition to developing depression increased the risk of experiencing depressive symptoms in peer victimised youth. To date, no study has explored such gene-environment interaction using a polygenic risk score for depression (PRS-depression) in the context of peer victimisation and depressive symptoms in adolescence. METHODS: The sample included 748 participants born in 1997/98 from the Quebec Longitudinal Study of Child Development with genotype data and prospectively collected information on peer victimisation (12-13 years) obtained from both self- and teacher-reports, as well as self-reported depressive symptoms (15-17 years). The PRS-depression was based on the genome-wide association meta-analysis of broad depression by Howard et al. (2019). RESULTS: Self- and teacher-reported peer victimisation in early adolescence were both associated with depressive symptoms in adolescence (ß = 0.34, p < .001; ß = 0.14, p = .001 respectively), and this association remained significant when accounting for PRS-depression (ß = 0.33, p < .001; ß = 0.13, p = .002 respectively). PRS-depression was independently associated with depressive symptoms, but there was no significant PRS-depression by peer victimisation interaction (self-reported and teacher-reported). PRS-depression was correlated with self-reported, but not teacher-reported, peer victimisation. CONCLUSIONS: Our findings suggested that a partial measure of an individual's genetic predisposition to depression, as measured by PRS-depression, and being exposed to peer victimisation (self- and teacher-reported) were independently associated with depressive symptoms in adolescence. Furthermore, PRS-depression did not exacerbate the risk of depressive symptoms among adolescents who had been peer victimised. Lastly, we found evidence of a gene-environment correlation between PRS-depression and self-reported peer victimisation. Future studies are needed to replicate this finding and to further understand the role of genetic predispositions in experiencing depressive symptoms following peer victimisation.

Early temperamental and biological predictors of dimensions of social withdrawal in childhood.

Social wariness and preference for solitude, two dimensions of social withdrawal, show unique associations with various socioemotional difficulties in childhood, including internalizing and peer problems. However, their early childhood predictors remain vastly undocumented. The present study aimed to examine whether early indicators of reactivity in situations of unfamiliarity such as behavioral inhibition, affect, and cortisol independently, or in interaction with emotion regulation as indexed by vagal tone, predict later social wariness and preference for solitude. Participants were 1209 children from the Quebec Newborn Twin Study. Vagal tone was assessed at 5 months, and behavioral inhibition, affect, and cortisol were assessed at 19 months in situations of unfamiliarity. Mothers, teachers, and peers evaluated social wariness and preference for solitude repeatedly from 4 to 10 years old. Findings show that three temperamental dimensions, social inhibition, nonsocial inhibition, and affect accounted for the variability in reactions to unfamiliarity. Behavioral inhibition to social unfamiliarity at 19 months predicted social wariness during the preschool years. Poor vagal regulation at 5 months exacerbated the risk associated with negative affect at 19 months to predict preference for solitude during the preschool years. Overall, results show that social wariness and preference for solitude may follow different developmental pathways.