Cohort Profile: Quebec Longitudinal Study of Child Development (QLSCD)

Prediction of depressive symptoms in young adults by polygenic score and childhood maltreatment: Results from a population-based birth cohort

Childhood maltreatment is linked with later depressive symptoms, but not every maltreated child will experience symptoms later in life. Therefore, we investigate whether genetic predisposition for depression (i.e., polygenic score for depression, PGSDEP) modifies the association between maltreatment and depressive symptoms, while accounting for different types of maltreatment and whether it was evaluated through prospective and retrospective reports. The sample included 541-617 participants from the Quebec Longitudinal Study of Child Development with information on maltreatment, including threat, deprivation, assessed prospectively (5 months-17 years) and retrospectively (reported at 23 years), PGSDEP and self-reported depressive symptoms (20-23 years). Using hierarchical linear regressions, we found that retrospective, but not prospective indicators of maltreatment (threat/deprivation/cumulative) were associated with later depressive symptoms, above and beyond the PGSDEP. Our findings also show the presence of gene-environment interactions, whereby the association between maltreatment (retrospective cumulative maltreatment/threat, prospective deprivation) and depression was strengthened among youth with higher PGSDEP scores. Consistent with the Diathesis-Stress hypothesis, our findings suggest that a genetic predisposition for depression may exacerbate the putative impact of maltreatment on later depressive symptoms, especially when maltreatment is retrospective. Understanding the gene-environment interplay emerging in the context of maltreatment has the potential to guide prevention efforts.

A longitudinal study of adolescent pathways differentiating suicide ideation and attempt in early adulthood

OBJECTIVE

Suicide ideation and attempt are leading risk factors for mortality in young adults. However, the adolescent risk factors distinguishing suicide ideation from attempt in young adults remain unclear. The present study aimed to examine the extent to which within-person stability and change in depressive symptoms, school difficulties, and peer victimization from ages 12 to 17 were differentially associated with later suicide ideation and attempt from ages 20 to 23.

METHOD

The study included 1647 participants from the Quebec Longitudinal Study of Child Development (QLSCD; 52% female). Participants reported on their depressive symptoms, school difficulties, and peer victimization at ages 12, 13, 15, and 17, and on suicide ideation and attempt at ages 20 and 23. Data were collected in the Province of Quebec, Canada, between 2010 and 2021.

RESULTS

Results indicated that 11% (N = 121) and 8% (N = 86) reported suicide ideation and attempt, respectively, between ages 20 and 23. A random-intercept cross-lagged panel model showed that within-person increases in depressive symptoms during adolescence were related to both suicide ideation and attempt, whereas within-person increases in school difficulties and peer victimization were for the most part related to suicide attempt only. Within-person stability in depressive symptoms from ages 12 to 17 years were also related to suicide attempt, and not ideation. However, this association was only marginally significant.

CONCLUSION

Findings suggest that experiencing unusual rises in school difficulties and peer victimization during adolescence, as well as depressive symptoms persisting over time, may distinguish young adults who think about suicide from those who attempt suicide.

Body mass index across development and adolescent hair cortisol: the role of persistence, variability, and timing of exposure

BACKGROUND

Research suggests a putative role of the glucocorticoid stress hormone cortisol in the accumulation of adiposity. However, obesity and weight fluctuations may also wear and tear physiological systems promoting adaptation, affecting cortisol secretion. This possibility remains scarcely investigated in longitudinal research. This study tests whether trajectories of body mass index (BMI) across the first 15 years of life are associated with hair cortisol concentration (HCC) measured two years later and whether variability in BMI and timing matter.

METHODS

BMI (kg/m2) was prospectively measured at twelve occasions between age 5 months and 15 years. Hair was sampled at age 17 in 565 participants. Sex, family socioeconomic status, and BMI measured concurrently to HCC were considered as control variables.

RESULTS

Latent class analyses identified three BMI trajectories: "low-stable" (59.2%, n = 946), "moderate" (32.6%, n = 507), and "high-rising" (8.2%, n = 128). BMI variability was computed by dividing the standard deviation of an individual's BMI measurements by the mean of these measurements. Findings revealed linear effects, such that higher HCC was noted for participants with moderate BMI trajectories in comparison to low-stable youth (β = 0.10, p = 0.03, 95% confidence interval (CI) = [0.02-0.40]); however, this association was not detected in the high-rising BMI youth (β = -0.02, p = 0.71, 95% CI = [-0.47-0.32]). Higher BMI variability across development predicted higher cortisol (β = 0.17, p = 0.003, 95% CI = [0.10-4.91]), additively to the contribution of BMI trajectories. BMI variability in childhood was responsible for that finding, possibly suggesting a timing effect.

CONCLUSIONS

This study strengthens empirical support for BMI-HCC association and suggests that more attention should be devoted to BMI fluctuations in addition to persistent trajectories of BMI.

Understanding bidirectional and transactional processes of child eating behaviours and parental feeding practices explaining poor health outcomes across infancy and early childhood in Australia: protocol for the Longitudinal Assessment of Children's Eating (LACE) study

INTRODUCTION

Child eating behaviours develop through interactions between the child's characteristics, psychological factors and the child's social environment and this affects the child's diet and weight. To examine the currently existing birth cohort studies examining child eating behaviours, a review was conducted. There are currently no birth cohorts that concurrently examine child eating behaviours, dietary intake, growth and parental feeding practices from birth into early childhood. Therefore, the primary objective of the Longitudinal Assessment of Children's Eating (LACE) study is to examine the bidirectional and transactional processes of child eating behaviours and parental feeding practices explaining poor dietary intake and excess weight across infancy and early childhood.

METHODS AND ANALYSIS

The LACE study will be a prospective, longitudinal parent-reported study following infants from younger than 4 months of age across nine waves of data collection: younger than 4 months, 4 months, 6 months, 9 months, 12 months, 18 months, 2 years, 3 years and 5 years. Participants will be included if they are parents of infants younger than 4 months, 18 years or older, fluent in English and living in Australia at baseline. A sample size of 1210 is proposed. Participants will be recruited online via paid social media (Facebook and Instagram) advertisements. The study will examine child eating behaviours, body mass index Z-score, dietary intake, screen time, temperament, parent feeding practices and styles, and demographics. The data will be obtained using the online survey software Qualtrics. Data analyses will be conducted using Stata.

ETHICS AND DISSEMINATION

Ethical approval was granted by the Deakin University Human Ethics Advisory Group, Faculty of Health (HEAG-H 120_2022). The findings from this study will be disseminated via presentations at scientific conferences and published manuscripts in peer-reviewed journals. Findings will be disseminated to the general public via mainstream media and to participants of the study with a summary of the findings.

Differential Association of Preadolescent Risk Factors Across Developmental Patterns of Adolescent Concurrent Gambling Participation and Substance Use

Early risk factors for gambling participation (GP) and substance use (SU) in adolescents have usually been studied separately, although these disorders were integrated into the same clinical category over a decade ago. This exploratory study aimed to investigate the early individual, parental, familial and social risk factors associated with developmental patterns of adolescent GP and SU in a population-representative cohort (N = 1594, 51.2% boys). Using a person-centered strategy and multiple assessments from age 12 to 17, six developmental patterns describing joint GP and SU courses were revealed. Non-substance users/non-gamblers served as the reference class in an integrated longitudinal-multivariate analysis framework examining 15 distinct risk factors. Results showed that a core of risk factors were common to all trajectory-classes of substance users with or without GP. For a similar level of SU, most of the risk factors associated with non-gambling users also affected their gambling peers. However, additional risk factors were specifically related to GP. Thus, substance users who also gamble were affected by a greater number of risk factors than non-gambling substance users. Findings are consistent with a developmental syndrome of addiction, which posits a shared etiology between different expressions of addiction as well as differences in risk factors that lead to distinct trajectories of addictive behaviors. They highlight the importance of considering both GP and SU for a comprehensive assessment of adolescents' level of risk with regard to addictive behaviors.

The interplay of maternal and paternal postpartum depressive symptoms with children's internalizing and externalizing symptoms from childhood to adolescence: does socioeconomic status matter? A longitudinal cohort study

BACKGROUND

Maternal postpartum depression is an important risk factor for internalizing and externalizing problems in children. The role of concurrent paternal depression remains unclear, especially by socioeconomic status. This study examined independent and interactive associations of postpartum maternal and paternal depression with children's internalizing/externalizing symptoms throughout childhood and adolescence (ages 3.5-17 years).

METHODS

We used data from the Québec Longitudinal Study of Child Development, a representative birth cohort (1997-1998) in Canada. Data included self-reported maternal and paternal depressive symptoms at 5 months' postpartum using the Center for Epidemiologic Studies Depression Scale. Internalizing and externalizing symptoms in children were reported by parents, teachers and children/adolescents using the Social Behaviour Questionnaire (ages 3.5-13 years) and the Mental Health and Social Inadaptation Assessment for Adolescents (ages 15-17 years). We used three-level mixed effects modelling to test associations after adjusting for confounding factors.

RESULTS

With 168 single-parent families excluded, our sample consisted of 1,700 families with useable data. Of these, 275 (16.2%) families reported maternal depression (clinically elevated symptoms), 135 (7.9%) paternal depression and 39 (2.3%) both. In families with high socioeconomic status, maternal depression was associated with greater child internalizing (β = .34; p < .001) and externalizing symptoms (β = .22; p = .002), regardless of the presence/absence of paternal depression. In families with low socioeconomic status, associations with symptoms were stronger with concurrent paternal depression (internalizing, β = .84, p < .001; externalizing, β = .71, p = .003) than without (internalizing, β = .30, p < .001; externalizing, β = .24, p = .002).

CONCLUSIONS

Maternal depression increases the risk for children's internalizing/externalizing problems in all socioeconomic contexts. In families with low socioeconomic status, risks were exacerbated by concurrent paternal depression. Postpartum depression, especially in low socioeconomic environments, should be a primary focus to optimize mental health across generations.

Evaluating the Link between Visual Attention Bias and Emotion Dysregulation of Young Children

The ability to regulate emotions is vital to successful social interactions. This study explores whether visual attention bias is associated with emotion dysregulation (ED) in early childhood. Parental reports of child ED (Child Behaviour Checklist (CBCL) and Temper Tantrum Scale) were examined in relation to child visual attention bias whilst viewing emotional faces. Results indicated that the level of eye gaze fixation towards emotional images and faces was associated with ED when social function (measured with the Social Responsiveness Scale), gender, age, and attention problems (measured from the CBCL subscale), were adjusted. The modifying effect on visual attention bias was evaluated using interaction analysis in the generalized linear model. The level of visual attention bias, indicated by the proportion of eye gaze fixation time on areas of interest (AOIs) in images displaying unpleasant emotions (such as anger), was inversely associated with the level of externalising problem behaviours (p = .014). Additionally, the association of eye gaze fixation time for AOIs displaying negative emotional cues with the level of externalising problem behaviours varied by age (p = .04), with younger children (aged < 70 months) demonstrating a stronger association than older children (aged ≥ 70 months). Findings suggest that young children with greater ED symptoms look less at unpleasant emotional cues. However, this relationship is attenuated as children become older. Further research to identify objective biomarkers that incorporate eye-tracking tasks may support prediction of ED-related mental health issues in the early years.

Childhood and Adolescent Depression Symptoms and Young Adult Mental Health and Psychosocial Outcomes

Importance

Depression is a leading cause of disability. The timing and persistence of depression may be differentially associated with long-term mental health and psychosocial outcomes.

Objective

To examine if depression symptoms during early and middle childhood and adolescence and persistent depression symptoms are associated with impaired young adult outcomes independent of early risk factors.

Design, Setting, and Participants

Data for this prospective, longitudinal cohort study were from the Québec Longitudinal Study of Child Development, a representative population-based Canadian birth cohort. The cohort consists of infants born from October 1, 1997, to July 31, 1998. This is an ongoing study; data are collected annually or every 2 years and include those ages 5 months to 21 years. The end date for the data in this study was June 30, 2019, and data analyses were performed from October 4, 2022, to January 3, 2024.

Exposures

Depression symptoms were assessed using maternal reports in early childhood (ages 1.5 to 6 years) from 1999 to 2004, teacher reports in middle childhood (ages 7 to 12 years) from 2005 to 2010, and self-reports in adolescence (ages 13 to 17 years) from 2011 to 2015.

Main Outcomes and Measures

The primary outcome was depression symptoms at age 20 years, and secondary outcomes were indicators of psychosocial functioning (binge drinking; perceived stress; not being in education, employment, or training; social support; and experiencing online harrasment) at age 21 years. All outcomes were self-reported. Adult outcomes were reported by participants at ages 20 and 21 years from 2017 to 2019. Risk factors assessed when children were aged 5 months old were considered as covariates to assess the independent associations of childhood and adolescent depression symptoms with adult outcomes.

Results

The cohort consisted of 2120 infants. The analytic sample size varied from 1118 to 1254 participants across outcomes (56.85% to 57.96% female). Concerning the primary outcome, adjusting for early risk factors and multiple testing, depression symptoms during adolescence were associated with higher levels of depression symptoms (β, 1.08 [95% CI, 0.84-1.32]; P < .001 unadjusted and Bonferroni adjusted) in young adulthood. Concerning the secondary outcomes, depression symptoms in adolescence were only associated with perceived stress (β, 3.63 [95% CI, 2.66-4.60]; P < .001 unadjusted and Bonferroni adjusted), while both middle-childhood (β, -1.58 [95% CI, -2.65 to -0.51]; P = .003 unadjusted and P < .001 Bonferroni adjusted) and adolescent (β, -1.97 [95% CI, -2.53 to -1.41]; P < .001 unadjusted and Bonferroni adjusted) depression symptoms were associated with lower levels of social support. There were no associations for binge drinking; not being in education, employment, or training; or experiencing online harrasment.

Conclusions and Relevance

In this cohort study of Canadian children and adolescents, childhood and adolescent depression symptoms were associated with impaired adult psychosocial functioning. Interventions should aim to screen and monitor children and adolescents for depression to inform policymaking regarding young adult mental health and psychosocial outcomes.

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.

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) (β = - 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 (β = - 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.

The intergenerational continuity of alcohol use in a population sample

INTRODUCTION

Research shows that parental alcohol use predicts youths' alcohol use, but this intergenerational continuity may vary across countries, and little is known about its moderators. This study examined for the first time the intergenerational continuity in alcohol use in a population sample of families in Canada, and tested whether it varied by youths' sex, family income, or family structure.

METHODS

We used prospective longitudinal data on 1632 families from the Quebec Longitudinal Study of Child Development (QLSCD), a representative sample from the province of Quebec, Canada. Youths self-reported alcohol use and binge drinking frequency at seven timepoints from early adolescence to early adulthood. Predictors were mothers' and fathers' self-reported alcohol use from youths' infancy through age 13, and mother-reported socioeconomic variables.

RESULTS

We identified three trajectories of alcohol use from ages 13 to 21 years: normative, late-onset and early-onset. Maternal alcohol use increased the youths' risk of following the early-onset trajectory of alcohol use, while both parents' alcohol use decreased the odds of the youths following the late-onset trajectory, compared to the normative trajectory. Insufficient family income increased youths' risk of following either the early-onset or late-onset trajectories. Mothers' and fathers' alcohol use did not interact in predicting youths' trajectory, and we found no moderating effects of the youths' sex, insufficient income, or years as a single-parent family.

CONCLUSION

The results suggest modest intergenerational continuity of alcohol use in Quebec families which may be used, with income insufficiency, to help identify at-risk children for targeted interventions.

Partners with a Highly Favorable Attitude Toward Breastfeeding Contribute to Promoting Initiation and Length of Breastfeeding for More than 5 Months in a Population-Based Canadian Study

Introduction: Promoting maternal breastfeeding for at least 6 months is important to improve children physical health during infancy and neurodevelopmental outcomes in childhood. For this guideline to be followed, it is paramount to identify what factors best support the initiation and length of breastfeeding. This study estimates the contribution of various child- and parent-level factors, as well as the sociodemographic context in predicting maternal breastfeeding initiation and duration. Methods: This study draws on data from the Quebec Longitudinal Study of Child Development. Mothers who never breastfed when the infant was 5 months old (n = 630, 28.3%) were compared to mothers who breastfed for less than 5 months (n = 844, 38.0%) and mothers breastfeeding for more than 5 months (n = 749, 33.7%), using multivariable multinomial regression models. Results: Mothers with a partner showing a positive attitude toward breastfeeding were up to 13 times more likely to breastfeed their infant for more than 5 months. The positive attitude of partners toward breastfeeding was the strongest predictor of breastfeeding duration, followed by the maternal educational attainment and timing she returns to work. Most prenatal and perinatal child-level factors and the sociodemographic context predicted breastfeeding duration, but to a lesser extent. Discussion: This finding underscores the role of the partner's attitude in promoting initiation and length of breastfeeding. As such, educational campaigns and health practitioners could target both the mother and their partner in promoting breastfeeding.

Longitudinal study of childhood sleep trajectories and adolescent mental health problems

Study Objective

To investigate whether childhood sleep trajectories are associated with mental health symptoms such as social phobia, generalized anxiety, depression, attention deficit hyperactivity disorder (ADHD), conduct problems, and opposition at age 15.

Methods

A total of 2120 children took part in the Quebec Longitudinal Study of Child Development. Childhood sleep trajectories were computed from maternal reports at 2.5, 3.5, 4, 6, 8, 10, and/or 12 years. At age 15, 1446 adolescents filled out mental health and sleep questions. A path analysis model was assessed in the full sample.

Results

Four childhood nocturnal sleep duration trajectories were identified: (1) a short pattern (7.5%), (2) a short-increasing pattern (5.8%), (3) a 10 hours pattern (50.7%), and (4) an 11 hours pattern (36.0%). Three childhood sleep latency trajectories were found: (1) a short pattern (31.7%), (2) an intermediate pattern (59.9%), and (3) a long pattern (8.4%). Finally, two childhood wakefulness after sleep-onset trajectories were found: (1) a normative pattern (73.0%) and (2) a long pattern (27.0%). The path analysis model indicated that children following a long childhood sleep latency trajectory were more likely to experience symptoms of depression (β = 0.06, 95% CI: 0.01 to 0.12), ADHD (β = 0.07, 95% CI: 0.02 to 0.13), conduct problems (β = 0.05, 95% CI: 0.00 to 0.10) and opposition (β = 0.08, 95% CI: 0.02 to 0.13) at age 15.

Conclusions

This longitudinal study revealed that children presenting a long sleep latency throughout childhood are at greater risk of symptoms of depression, ADHD, conduct problems, and opposition in adolescence.

Polygenic risk and hostile environments: Links to stable and dynamic antisocial behaviors across adolescence

Adverse environments are linked to elevated youth antisocial behavior. However, this relation is thought to depend, in part, on genetic susceptibility. The present study investigated whether polygenic risk for antisociality moderates relations between hostile environments and stable as well as dynamic antisocial behaviors across adolescence. We derived two antisocial-linked polygenic risk scores (PRS) (N = 721) based on previous genome-wide association studies. Forms of antisocial behavior (nonaggressive conduct problems, physical aggression, social aggression) and environmental hostility (harsh parenting and school violence) were assessed at age 13, 15, and 17 years. Relations to individual differences stable across adolescence (latent stability) vs. time-specific states (timepoint residual variance) of antisocial behavior were assessed via structural equation models. Higher antisocial PRS, harsh parenting, and school violence were linked to stable elevations in antisocial behaviors across adolescence. We identified a consistent polygenic-environment interaction suggestive of differential susceptibility in late adolescence. At age 17, harsher parenting was linked to higher social aggression in those with higher antisocial PRS, and lower social aggression in those with lower antisocial PRS. This suggests that genetics and environmental hostility relate to stable youth antisocial behaviors, and that genetic susceptibility moderates home environment-antisocial associations specifically in late adolescence.

Prospective associations between ADHD symptoms and physical conditions from early childhood to adolescence: a population-based longitudinal study

BACKGROUND

The co-occurrence between attention-deficit hyperactivity disorder (ADHD) and physical conditions is frequent but often goes unrecognised. Most available evidence on the links between ADHD and physical conditions relies on cross-sectional studies. Understanding temporal sequences of associations is key to inform appropriate treatment and preventive strategies. We aimed to assess possible longitudinal associations between ADHD symptoms and a broad range of physical conditions, adjusting for several confounding factors.

METHODS

Participants came from the population-based Quebec Longitudinal Study of Child Development. Participants were selected from the Quebec Birth Registry, recruited between October, 1997, and July, 1998, from the province of Quebec, Canada, and followed up in early childhood (n=2120; age 5 months-5 years), middle childhood (n=1750; age 6-12 years), and adolescence (n=1573; age 13-17 years). Main outcome measures included ADHD symptom severity and physical conditions, which were reported by the person most knowledgeable of the child in early childhood, by teachers in middle childhood, and self-reported in adolescence. Multivariable regression analyses were conducted to study the prospective associations between ADHD symptoms and later physical conditions, and physical conditions and later ADHD symptoms, adjusting for multiple confounders.

FINDINGS

We found several prospective associations between ADHD symptoms and physical conditions including asthma, high BMI (≥1 SD above the mean), epilepsy, dental caries, acute infections, injuries, and sleep problems. After adjusting for key confounding factors, several associations remained: ADHD symptoms in early childhood were associated with later high BMI during middle childhood (odds ratio [OR] 1·19 [95% CI 1·05-1·35]) and adolescence (OR 1·14 [1·01-1·29]), and with unintentional injuries during adolescence (OR 1·10 [1·01-1·21]). ADHD symptoms in middle childhood were significantly associated with later dental caries during adolescence (OR 1·10 [1·01-1·20]). Unintentional injuries in early childhood were associated with later ADHD symptoms in middle childhood (standardised mean difference [SMD] 0·15 [0·05-0·24]) and adolescence (SMD 0·13 [0·04-0·23]), and restless legs syndrome symptoms in middle childhood were associated with later ADHD symptoms in adolescence (SMD 0·15 [0·05-0·25]).

INTERPRETATION

Our results point to the need to carefully monitor children with ADHD in early or middle childhood for several physical conditions, and to monitor children with particular physical conditions for ADHD symptoms. Our study also calls for policies to promote more integrated health-care systems for children with complex mental and physical needs, bridging the current gap between mental and physical health-care services.

FUNDING

Québec Government's Ministry of Health, Ministry of Education, and Ministry of Family Affairs; The Lucie and André Chagnon Foundation; the Robert-Sauvé Research Institute of Health and Safety at Work; the Québec Statistics Institute; the Fonds de Recherche du Québec-Santé; the Fonds de Recherche du Québec-Societé et Culture; Canada's Social Science and Humanities Research Council; the Canadian Institutes of Health Research, the Sainte-Justine Research Center; and the French National Research Agency.

TRANSLATION

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

Unraveling the effects of maternal breastfeeding duration and exclusive breast milk on children's cognitive abilities in early childhood

Background

This study investigated the putative associations between mothers' use of exclusive breast milk and the duration of breastfeeding with child cognitive development.

Methods

This study is based on 2,210 Canadian families with children assessed longitudinally from age 4 to 7 years on their memory-span and math skills. These cognitive abilities were measured with standardized tasks. Breastfeeding practices were collected via maternal reports. We applied propensity scores to control the social selection bias for breastfeeding.

Results

Results adjusted for propensity scores and sample weight revealed no significant differences between non-breastfed children with those being non-exclusively breastfed for 5 months or less, and with children being exclusively breastfed for 9.2 months on average, on their early math skills and memory-span. We found that children who were non-exclusively breastfed for 6.8 months on average had a slightly higher levels of memory-span at age 4 than children who were never breastfed, and this small but significant difference lasted up to age 7.

Conclusion

Our findings suggest no significant differences between children being exclusively breastfed and those fed with formula on their early math skills and memory-span. The encouragement of breastfeeding to promote child cognitive school readiness may, in some case (non-exclusive breastfeeding for more than 5 months), show a small but long-lasting advantage in early memory-span.

Experiencing food insecurity in childhood: influences on eating habits and body weight in young adulthood

OBJECTIVE

To examine how food insecurity in childhood up to adolescence relates to eating habits and weight status in young adulthood.

DESIGN

A longitudinal study design was used to derive trajectories of household food insecurity from age 4·5 to 13 years. Multivariable linear and logistical regression analyses were performed to model associations between being at high risk of food insecurity from age 4·5 to 13 years and both dietary and weight outcomes at age 22 years.

SETTING

A birth cohort study conducted in the Province of Quebec, Canada.

PARTICIPANTS

In total, 698 young adults participating in the Québec Longitudinal Study of Child Development.

RESULTS

After adjusting for sex, maternal education and immigrant status, household income and type of family, being at high risk (compared with low risk) of food insecurity in childhood up to adolescence was associated with consuming higher quantities of sugar-sweetened beverages (ßadj: 0·64; 95 % CI (0·27, 1·00)), non-whole-grain cereal products (ßadj: 0·32; 95 % CI (0·07, 0·56)) and processed meat (ßadj: 0·14; 95 % CI (0·02, 0·25)), with skipping breakfast (ORadj: 1·97; 95 % CI (1·08, 3·53)), with eating meals prepared out of home (ORadj: 3·38; 95 % CI (1·52, 9·02)), with experiencing food insecurity (ORadj: 3·03; 95 % CI (1·91, 4·76)) and with being obese (ORadj: 2·01; 95 % CI (1·12, 3·64)), once reaching young adulthood.

CONCLUSION

Growing up in families experiencing food insecurity may negatively influence eating habits and weight status later in life. Our findings reinforce the importance of public health policies and programmes tackling poverty and food insecurity, particularly for families with young children.

Childhood hyperactivity, eating behaviours, and executive functions: Their association with the development of eating-disorder symptoms in adolescence

BACKGROUND

Cross-sectional studies have shown that hyperactivity and impaired executive functioning are associated with symptoms of eating disorders in adolescence and adulthood. Whether hyperactivity and executive functions in early life can prospectively predict the emergence of eating disorder symptoms in adolescence remains unknown. The present study relies on a longitudinal design to investigate how hyperactivity at age 3, eating behaviours at age 3.5 and cognition at ages 3-6 were associated with the development of eating-disorder symptoms from 12 to 20 years old.

METHODS

Using archival data collected since 1997 from the Quebec Longitudinal Study of Child Development cohort (N = 2, 223), we used Latent Curve Models to analyse predictors of youth's trajectories of eating-disorder symptoms at four timepoints.

RESULTS

A quadratic (curvilinear) trajectory of eating-disorder symptoms was found to be most representative of the data. Higher hyperactivity at age 3 was associated with higher levels of eating-disorder symptoms at age 12, and this association was partially mediated by higher levels of overeating and cognitive inflexibility in childhood. Cognitive inflexibility in childhood also mediated the association between hyperactivity at age 3 and increases in eating-disorder symptoms during adolescence. Furthermore, working memory was indirectly related to eating-disorder symptoms via the mediational role of cognitive flexibility.

CONCLUSIONS

Hyperactivity, overeating, cognitive inflexibility, and working memory early in life might precede the onset of eating-disorder symptoms in adolescence. Early behavioural and cognitive screening may help to identify children who are most at risk for eating disorders. This, in turn, could guide preventive interventions.

Adolescents' internalizing symptoms predict dating violence victimization and perpetration 2 years later

The aim of this longitudinal study was to examine bidirectional associations of adolescents' internalizing symptoms with dating violence victimization and perpetration. We conducted secondary analyses of the Québec Longitudinal Study of Child Development data (n = 974). Each adolescent completed items from the Conflict Tactics Scale (at ages 15 and 17 years) to assess psychological, physical, and sexual dating violence victimization and perpetration in the past 12 months. Adolescents' symptoms of depression and general anxiety in the past 12 months were self-reported (at ages 15 and 17 years) using The Mental Health and Social Inadaptation Assessment for Adolescents. There were concurrent associations of adolescents' internalizing symptoms with dating violence victimization and perpetration. Internalizing symptoms at age 15 years were positively associated with dating violence victimization and perpetration 2 years later in both males and females, even after adjusting for baseline characteristics. However, neither dating violence victimization nor perpetration at age 15 years was associated with internalizing symptoms 2 years later. For males and females, internalizing symptoms put adolescents at risk for future dating violence victimization and perpetration. Interventions that target internalizing symptoms may have the potential to decrease subsequent dating violence.

Evaluating the feasibility and outcomes of a resident-led school-based pediatric clinic

Objective

A resident-led school-based clinic to serve low-income populations was established in 2019 and served as a continuity clinic for pediatric residents at a single university. Our aim was to assess the feasibility, clinic outcomes, and resident experience of a resident-led school-based clinic (RLSBC), established in an elementary school that serves an underserved population.

Methods

A retrospective chart review for the first 6 months (October 2019 to March 2020) of clinic operations was conducted. Feasibility metrics included the number of patients, visits and planned follow-ups; clinic outcomes included the number and type of presenting complaint, new diagnoses and interventions. Residents were also surveyed to assess their satisfaction and perceived learning in training at the school-based clinic.

Results

Over the first 19 clinic days, 48 children were seen at the school-based clinic. Of the clinic users, 60% did not have a primary care physician, 46% received a new diagnosis, 46% received an intervention in the form of medication prescription, laboratory/imaging requisitions or referrals, and 96% received a treatment plan. Residents positively rated the experience of staffing the school-based clinic in all aspects, including learning environment, clinic and team environment, teaching obtained, practice management, and overall experience.

Conclusion

A RLSBC is feasible and our outcomes suggest that such clinics may address health care needs of low-income families and children, while being a positively rated educational experience for pediatric residents.

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.

Childhood Overeating and Disordered Eating From Early Adolescence to Young Adulthood: A Longitudinal Study on the Mediating Role of BMI, Victimization and Desire for Thinness

Eating disorders have early origins, and there could be a continuum between childhood eating behaviors, such as overeating, and long-term disordered eating, but this remains to be shown. BMI, desire for thinness and peer victimization could influence this continuum, but their interactions are unknown. To fill this gap, the study used data from the Quebec Longitudinal Study of Child Development (N = 1511; 52% girls), in which 30.9% of youth presented a trajectory associated with high disordered eating from 12 to 20 years. The results support an indirect association between overeating at age 5 and disordered eating trajectories, with different mediation processes observed between boys and girls. The findings underscore the importance of promoting healthy body images and eating behaviors among youths.

Depression, anxiety, and suicidal ideation in a population-based cohort of young adults before and during the first 12 months of the COVID-19 pandemic in Canada

OBJECTIVES

Findings from a birth cohort study indicated that the mental health of young adults had not worsened during the first wave of the COVID-19 pandemic, compared to 2018. This study examined longitudinal changes in mental health between March 2018 and June 2021 in the context of protracted public health mitigation measures about 12 months after the onset of the pandemic.

METHODS

Participants from the Quebec Longitudinal Study of Child Development (n = 2120 at inception; n = 1461 during the COVID-19 pandemic), a population-based cohort of individuals born in 1997/1998, reported on their depressive and anxiety symptoms as well as suicidal ideation prior to the pandemic in 2018 (age 20), and during the pandemic in the summer of 2020 (age 22) and spring of 2021 (age 23).

RESULTS

Depressive (Cohen's d = 0.15 [95% CI: 0.09 to 0.20]) and anxiety (Cohen's d = 0.33 [95% CI: 0.27 to 0.39]) symptoms increased between 2018 and 2021 for both males and females, but suicidal ideation did not change. There was also a significant increase in moderate to severe depressive (31.7% to 36.3%) and anxiety (14.7% to 24.8%) symptoms from 2018 to 2021. Youth who were students, those who were experiencing financial stress, food insecurity, and loneliness, and those without pre-existing poor mental health experienced the largest increase in depressive and anxiety symptoms over time.

CONCLUSION

These findings highlight the mental health burden experienced by young adults during the COVID-19 pandemic, highlighting the need for preventive services and continued longitudinal follow-ups of these youths.

Mental health comorbidities following peer victimization across childhood and adolescence: a 20-year longitudinal study

BACKGROUND

Peer victimization is associated with a wide range of mental health problems in youth, yet few studies described its association with mental health comorbidities.

METHODS

To test the association between peer victimization timing and intensity and mental health comorbidities, we used data from 1216 participants drawn from the Quebec Longitudinal Study of Child Development, a population-based birth cohort. Peer victimization was self-reported at ages 6-17 years, and modeled as four trajectory groups: low, childhood-limited, moderate adolescence-emerging, and high-chronic. The outcomes were the number and the type of co-occurring self-reported mental health problems at age 20 years. Associations were estimated using negative binomial and multinomial logistic regression models and adjusted for parent, family, and child characteristics using propensity score inverse probability weights.

RESULTS

Youth in all peer victimization groups had higher rates of co-occurring mental health problems and higher likelihood of comorbid internalizing-externalizing problems [odds ratios ranged from 2.06, 95% confidence interval (CI) 1.52-2.79 for childhood-limited to 4.34, 95% CI 3.15-5.98 for high-chronic victimization] compared to those in the low victimization group. The strength of these associations was highest for the high-chronic group, followed by moderate adolescence-emerging and childhood-limited groups. All groups also presented higher likelihood of internalizing-only problems relative to the low peer victimization group.

CONCLUSIONS

Irrespective of timing and intensity, self-reported peer victimization was associated with mental health comorbidities in young adulthood, with the strongest associations observed for high-chronic peer victimization. Tackling peer victimization, especially when persistent over time, could play a role in reducing severe and complex mental health problems in youth.

Developmental Patterns of Gambling Participation and Substance use Throughout Adolescence in a Population Birth Cohort

This study investigated adolescents' single and co-occurring developmental patterns of gambling participation and substance use and their association with gambling and substance use-related issues at age 17, controlling for confounders. Multiple assessments from age 12 to 17 were conducted in a population-based cohort (N=1594, 51.2% boys). Latent growth modeling was used to analyze developmental patterns and Generalized linear models to examine their association with age-17 gambling and substance use-related problems, types and variety of activities, and substance abuse. Results revealed six developmental patterns, including Low- or Non-substance Users or Gamblers (24.2% sample), two trajectory-classes of Later-Onset Increasing (to a moderate level) substance users, either with or without gambling participation (7.8% and 45.5%, respectively), two trajectory-classes of Early-Onset Increasing (to a higher level) substance users, either with or without gambling participation (6.2% and 12.7%, respectively), and a smaller trajectory-class of Slow-Increasing Substance Users and Early-Onset Gamblers, declining to non-gambling after age 13 (3.6%). Gambling participation and substance use did not appear to influence each other with regard to their onset and course throughout adolescence, and to age-17 types and variety of gambling activities or substances used, problems related to gambling participation or substance use, or substance abuse. These findings are consistent with the addictive syndrome model and with both common and individualized approaches to prevention and treatment for adolescent gamblers or substance users.

Protocol for the Open Sky School: a two-arm clustered randomized controlled trial to test the effectiveness of a nature-based intervention on mental health of elementary school children

BACKGROUND

This article outlines the protocol for a trial to test the effectiveness of a nature-based intervention called Open Sky School to reduce mental health problems among elementary school children. Experimental studies show that contact with nature (e.g. walks in parks) improve mental health. A growing number of teachers have been applying outdoor education within the regular school curriculum and evidence suggests that such teaching methods could improve students' mental health but a randomized controlled trial has never been conducted.

METHODS

A two-arm clustered randomized controlled trial will be conducted in elementary schools across Québec, Canada. Following informed consent by teachers, parents and students, schools will be randomly assigned 1:1 to the intervention or the control group with a total of 2500 5-6^th grade students and 100 teachers expected to participate. The intervention will take place outdoors in a green-space (2 h per week for 12 weeks) and include a toolkit of 30 activities to foster well-being (e.g. mindfulness) and academic competencies (e.g. mathematics). Questionnaires will be administered to teachers and students before, immediately after and 3 months after the intervention. The primary outcome will be reductions of mental health problems in children from pre-to-post test (Social Behavior Questionnaire: self and teacher reports). Secondary outcomes include depression, positive and negative affect, nature connectedness, and pro-environmental behaviors among children. We will explore, immediate benefits on teacher's well-being and positive and negative affect and sustained benefits among students at 3 months follow-up. For the primary outcome, we will explore moderators including child's sex, child's disability status, the green-space of neighbourhoods, the school's socio-economic position and teacher's experience.

DISCUSSION

In conducting the first randomized controlled trial of the Open Sky School, our results could provide empirical evidence on the effectiveness of nature-based interventions in reducing mental health problems among elementary school children.

TRIAL REGISTRATION

This study was registered with clinicaltrials.gov: NCT05662436 on December 22, 2022.

Pathways of association between disordered eating in adolescence and mental health outcomes in young adulthood during the COVID-19 pandemic

OBJECTIVES

The COVID-19 pandemic has been associated with increased mental health problems. We investigated (1) associations between disordered eating in adolescence and mental health problems after one year of the pandemic and (2) the mechanisms explaining associations.

METHOD

We analyzed data from a population-based birth cohort in Quebec, Canada (557 males and 759 females). High and low levels of disordered eating symptom trajectories were previously estimated (age 12, 15, 17, and 20 years). Anxiety, depression, non-suicidal self-injury, and suicidal ideation were assessed at 23 years (March-June 2021). Putative mediators included loneliness and social media use (age 22 years, July-August 2020). Analyses controlled for mental health and socio-economic status at age 10-12 years and were conducted for males and females separately.

RESULTS

Females in the high-level disordered eating symptom trajectory were at increased risk for non-suicidal self-injury (OR 1.60; 95% CI 1.02-2.52) and suicidal ideation (2.16; 1.31-3.57), whereas males were at increased risk for severe anxiety (2.49; CI 1.11-5.58). Males and females in the high-level trajectory were more likely to report severe depression (2.26; 1.14-5.92 and 2.15, 1.36-3.38 respectively). Among females, associations were partially explained (17-35%) by loneliness during the first 4 months of the pandemic.

CONCLUSION

Young adults who experienced disordered eating as adolescents were at increased risk of mental health problems during the pandemic. Loneliness partially mediated the effect, suggesting that pandemic mitigation resulting in increased social isolation may have exacerbated mental health problems among women with a history of disordered eating.

Associations between epigenetic aging and childhood peer victimization, depression, and suicidal ideation in adolescence and adulthood: A study of two population-based samples

Background: Prior studies indicate that peer victimization (including bullying) is associated with higher risk for depression and suicidal ideation across the life course. However, molecular mechanisms underlying these associations remain unclear. This two-cohort study proposes to test whether epigenetic aging and pace of aging, as well as a DNA methylation marker of responsive to glucocorticoids, are associated to childhood peer victimization and later depressive symptoms, or suicidal ideation. Methods: Cohort 1: Epigenome-wide DNA methylation (EPIC array) was measured in saliva collected when participants were 10.47 years (standard deviation = 0.35) in a subsample of the Quebec Longitudinal Study of Child Development (QLSCD, n = 149 participants), with self-reported peer victimization at 6-8 years, depressive symptoms (mean symptoms, and dichotomized top 30% symptoms) and suicidal ideation at 15-17 years. Cohort 2: Epigenome-wide DNA methylation (EPIC array) was measured in blood collected from participants aged 45.13 years (standard deviation = 0.37) in a subsample of the 1958 British Birth cohort (1958BBC, n = 238 participants) with information on mother-reported peer victimization at 7-11 years, self-reported depressive symptoms at 50 years, and suicidal ideation at 45 years. Five epigenetic indices were derived: three indicators of epigenetic aging [Horvath's pan-tissue (Horvath1), Horvath's Skin-and-Blood (Horvath2), Pediatric-Buccal-Epigenetic age (PedBE)], pace of aging (DunedinPACE), and stress response reactivity (Epistress). Results: Peer victimization was not associated with the epigenetic indices in either cohort. In the QLSCD, higher PedBE epigenetic aging and a slower pace of aging as measured by DunedinPACE predicted higher depressive symptoms scores. In contrast, neither the Horvath1, or Horvath2 epigenetic age estimates, nor the Epistress score were associated with depressive symptoms in either cohort, and none of the epigenetic indices predicted suicidal ideation. Conclusion: The findings are consistent with epigenome-wide and candidate gene studies suggesting that these epigenetic indices did not relate to peer victimization, challenging the hypothesis that cumulative epigenetic aging indices could translate vulnerability to depressive symptoms and suicidal ideation following peer victimization. Since some indices of epigenetic aging and pace of aging signaled higher risk for depressive symptoms, future studies should pursue this investigation to further evaluate the robustness and generalization of these preliminary findings.

Child Cognitive Flexibility and Maternal Control: A First Step toward Untangling Genetic and Environmental Contributions

Executive functions (EF) play an essential role in many spheres of child development. Therefore, it is crucial to get a better understanding of their etiology. Using a genetic design that involved 934 twins (400 monozygotic), this study examined the etiology of cognitive flexibility, a component of EF, at 5 years of age and its phenotypic and etiological associations with maternal control. Cognitive flexibility was measured in a laboratory setting at 5 years of age using a well-known EF-task, i.e. the Dimensional Change Card Sort (DCCS). Maternal control was measured using a self-report questionnaire. The univariate genetic model demonstrated that environmental factors mainly explained individual differences in preschoolers' performance on the DCCS task. A bivariate genetic model demonstrated that non-shared environmental mechanisms mainly explained the association (r = .-13) between maternal control and children's performance on the DCCS task. This study represents a preliminary step toward a better understanding of the genetic and environmental contributions underlying the relation between parenting behaviors and children's EF.

Simultaneous exposure to both Zika virus and household insecticides during pregnancy, and fetal growth and infant developmental behavior outcomes at 18 months, in Guadeloupe

BACKGROUND

Perinatal infection with Zika virus (ZIKV) could result in adverse growth, developmental and behavioral outcomes, while insecticides used to control mosquitoes are neurotoxic.

OBJECTIVES

We aim to study the role played by exposure during pregnancy to both ZIKV and household insecticides in newborn health, development and behavior at age of 18 months.

METHODS

Maternal and cord blood samples from a cohort of pregnant women (created during Guadeloupe's Zika epidemic of 2016) were used to identify ZIKV infection during pregnancy. A self-administered questionnaire at birth documented prenatal household use of insecticides. Birth weight and head circumference were collected from maternity records (n = 708). Infant development and behaviors were documented at 18 months of age through the Ages and Stages Questionnaire and the Quebec Longitudinal Study of Child Development (n = 409). Logistic and linear regression models were performed, taking into account confounding factors.

RESULTS

Use of household insecticides was associated with smaller head circumference and lower birth weight among newborns from mothers not exposed to ZIKV: 0.3 cm (95% CI: 0.6, 0) and -82 g (95% CI: 165, 0), respectively. Similar decreases were observed with ZIKV exposure among mothers not reporting household insecticides use, and with presence of both exposures. The combined presence of ZIKV exposure and insecticide use was associated with lower ASQ fine motor scores (-3.9; 95% CI: 7.3, -0.4), and higher hyperactivity scores (0.8; 95% CI: 0.0, 1.5), compared to no exposure to either. A higher opposition score was observed in association with ZIKV exposure among non-users of insecticide (0.6; 95% CI: 0.0, 1.2).

CONCLUSION

Adverse neurodevelopmental outcomes at 18 months of age were observed with prenatal ZIKV exposure, and with higher magnitude when mothers reported use of household insecticides. At birth, rates of adverse fetal growth were however similar for the combined presence of exposure and either of the exposures.

Eating behaviors, dietary patterns and weight status in emerging adulthood and longitudinal associations with eating behaviors in early childhood

Background

Eating behaviors may contribute to differences in body weight and diet over time. Our study aims to examine how eating behaviors of young adults relate to their current weight status and dietary patterns and to explore longitudinal associations with eating behaviors in early childhood.

Methods

Study participants are young adults (n = 698) taking part in the Quebec Longitudinal Study of Child Development. At age 22, eating behaviors were assessed using the Adult Eating Behavior Questionnaire. Dietary patterns were derived from information collected by food frequency questions. Weight status was based on self-reported data. Information on eating behaviors in childhood had been collected when participants were 2.5 to 6 years old. Pearson’s correlations were used to determine associations between adult eating behaviors and body mass index. Simple and multivariate linear regression analyses were used to examine associations between eating behaviors and dietary patterns at age 22, and longitudinal associations with behaviors in early childhood. Ordinal logistic regression analyses were used to assess associations between overeating and fussy eating in childhood and weight status at age 22.

Results

Body mass index was positively correlated with Emotional overeating, Enjoyment of food, and Food responsiveness and negatively correlated with Satiety responsiveness, Emotional undereating, Slowness in eating and Hunger. A Healthy dietary pattern was positively associated with both Enjoyment of food and Hunger, and negatively associated with Food fussiness. Inversely, a Beverage-rich dietary pattern was negatively associated with Enjoyment of food and positively associated with Food fussiness. A Protein-rich pattern was positively associated with Enjoyment of food, while a High energy density pattern was positively associated with Food fussiness. Young adults with higher scores for fussy eating in early childhood were more likely to manifest Food fussiness and Emotional undereating, and less likely to adopt a Healthy dietary pattern. Young adults with higher scores for overeating in early childhood were less likely to show traits such as Slowness in eating and more likely to be overweight.

Conclusions

Our findings suggest that eating behaviors in childhood have long-term influence on diet and weight status, thereby reinforcing the importance of early interventions that promote healthy eating.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-022-01376-z.

Uncovering the genetic architecture of broad antisocial behavior through a genome-wide association study meta-analysis

Despite the substantial heritability of antisocial behavior (ASB), specific genetic variants robustly associated with the trait have not been identified. The present study by the Broad Antisocial Behavior Consortium (BroadABC) meta-analyzed data from 28 discovery samples (N = 85,359) and five independent replication samples (N = 8058) with genotypic data and broad measures of ASB. We identified the first significant genetic associations with broad ASB, involving common intronic variants in the forkhead box protein P2 (FOXP2) gene (lead SNP rs12536335, p = 6.32 × 10-10). Furthermore, we observed intronic variation in Foxp2 and one of its targets (Cntnap2) distinguishing a mouse model of pathological aggression (BALB/cJ strain) from controls (BALB/cByJ strain). Polygenic risk score (PRS) analyses in independent samples revealed that the genetic risk for ASB was associated with several antisocial outcomes across the lifespan, including diagnosis of conduct disorder, official criminal convictions, and trajectories of antisocial development. We found substantial genetic correlations of ASB with mental health (depression rg = 0.63, insomnia rg = 0.47), physical health (overweight rg = 0.19, waist-to-hip ratio rg = 0.32), smoking (rg = 0.54), cognitive ability (intelligence rg = -0.40), educational attainment (years of schooling rg = -0.46) and reproductive traits (age at first birth rg = -0.58, father's age at death rg = -0.54). Our findings provide a starting point toward identifying critical biosocial risk mechanisms for the development of ASB.

Maternal depressive symptoms and children's academic performance: sex differences in the mediating role of school experiences

BACKGROUND

Maternal depressive symptoms (MDSs) are negatively associated with children's academic performance, with stronger effects sometimes reported in boys. However, few studies have tested the mechanisms of this association. We examined the mediating role of school engagement and peer victimization in this association and tested for sex differences.

METHODS

Participants were 1173 families from a population-based longitudinal Canadian study. MDSs were self-reported annually using the Centre for Epidemiologic Studies Depression Scale (child's age: 5 months to 5 years). Data on mediators (peer victimization, cognitive, behavioral, and emotional school engagement) were reported annually from ages 6-10 by multiple informants including children, parents, and teachers using items from validated scales. Mathematics, reading, and writing exam scores at age 12 were obtained from standardized exams administered by Québec's Ministry of Education and Teaching. Structural equation modeling was used to test mediation by school experiences in boys and girls.

RESULTS

Exposure to MDSs was negatively associated with mathematics, reading, and writing scores in girls and with mathematics only in boys. Cognitive and behavioral engagement significantly mediated the association between MDSs and mathematics, reading, and writing scores in girls. There were no significant mediators for boys.

CONCLUSIONS

Prevention and intervention strategies aiming to improve school engagement might be beneficial for daughters of mothers experiencing depressive symptoms. Further research is needed to replicate these findings and to identify the mechanisms explaining this association in boys.

Psychometric properties of the Social Behavior Questionnaire (SBQ) in a longitudinal population-based sample

We assessed the psychometric properties of the Social Behavior Questionnaire (SBQ), a 30-item questionnaire evaluating social (e.g., disruptive behaviors, bullying) and emotional problems (e.g., anxiety, depression) among children aged 3.5–12 years. Children ( n = 1,950, 50.21% boys) were drawn from the Quebec Longitudinal Study of Child Development. Mothers reported the frequency with which children presented social and emotional behaviors from 3.5 to 8 years of age, and teachers from 6 to 12 years. We assessed internal structure using Confirmatory Factor Analysis, reliability using Cronbach’s alpha, and convergent and discriminant validity using a multitrait-multimethod (MTMM) approach. The six-factor (emotional distress, withdrawal, impulsive/hyperactive/inattentive, disruptive behaviors, prosocial behaviors, and peer relationships difficulties) structure of the SBQ showed good fit from ages 3.5 to 12 years. Reliability estimates were good to excellent (alphas > .7), and MTMM showed good convergent and discriminant validity. Overall, the SBQ presented good psychometric properties with a large population-based sample aged 3.5–12 years. Further studies should assess its screening potential by investigating its convergent validity with diagnostic information.

Testing Bidirectional, Longitudinal Associations Between Disturbed Sleep and Depressive Symptoms in Children and Adolescents Using Cross-Lagged Models

IMPORTANCE

Understanding the longitudinal, bidirectional associations between disturbed sleep and depression in childhood and adolescence is crucial for the development of prevention and intervention programs.

OBJECTIVE

To test for bidirectional associations and cascade processes between disturbed sleep and depressive symptoms covering both childhood and adolescence and to test for the moderating processes of sex and pubertal status in adolescence.

DESIGN, SETTING, AND PARTICIPANTS

A prospective cohort study using the Québec Longitudinal Study of Child Development (QLSCD; 1997-ongoing). QLSCD's objective is to identify early childhood factors associated with long-term psychosocial and academic adjustment. Data were collected across 8 waves between ages 5 years (2003) and 17 years (2015). Associations were tested through cross-lagged models in childhood (5, 7, and 8 years), and in adolescence (10, 12, 13, 15, and 17 years). Data were analyzed from February to October 2021.

MAIN OUTCOMES AND MEASURES

Primary outcomes were disturbed sleep and depressive symptoms. Disturbed sleep was parent-reported and included sleep duration, time awake in bed, daytime sleepiness, sleep talking, sleepwalking, night terrors, and nightmares. Depressive symptoms were parent-reported in childhood (Child Behavior Checklist and Revised Ontario Child Health Study Scales), and self-reported in adolescence (Mental Health and Social Inadaptation Assessment for Adolescents).

RESULTS

Data on 1689 children (852 female [50.4%]) and 1113 adolescents (595 female [53.5%]) were included in the analyses. In childhood, significant bidirectional associations between depressive symptoms and disturbed sleep at all time points were found, indicating cascade processes (range β = 0.07; 95% CI, 0.02-012 to β = 0.15; 95% CI, 0.10-0.19). In adolescence, significant bidirectional associations from depressive symptoms to disturbed sleep (β = 0.09; 95% CI, 0.04-0.14) and vice versa (β = 0.10; 95% CI, 0.04-0.16) between 10 and 12 years were found. Between 12 and 13 years, depressive symptoms were modestly associated with disturbed sleep (β = 0.05; 95% CI, 0.001-0.10) but the reverse association was not significant. Cross-lagged estimates were nonsignificant after 13 years. The associations did not vary as a function of either sex or puberty-by-sex.

CONCLUSIONS AND RELEVANCE

These findings suggest that disturbed sleep is associated with the consolidation of depressive symptoms starting in childhood, which, in turn, is associated with ongoing sleep problems. It is possible that timely and appropriate interventions for incipient disturbed sleep and depression prevent spiraling effects on both domains.

Developmental trajectories of eating disorder symptoms: A longitudinal study from early adolescence to young adulthood

BACKGROUND

Adolescence is a critical period for the development of eating disorders, but data is lacking on the heterogeneity of their evolution during that time-period. Group-based trajectories can be used to understand how eating disorders emerge and evolve over time. The aim of this study was to identify groups of individuals with distinct levels of eating disorder symptoms between 12 and 20 years and the onset of different types of symptoms. We also studied sex differences in the evolution and course of eating disorder symptoms from early adolescence to adulthood.

METHODS

Using archival data from the QLSCD cohort, trajectories of eating disorder symptomatology were estimated from ages 12 to 20 years using semiparametric models. These trajectories included overall eating disorder symptomatology as measured by the SCOFF (Sick, Control, One Stone, Fat, Food), sex, and symptom-specific trajectories.

RESULTS

Two groups of adolescents following distinct trajectories of eating disorder symptoms were identified. The first trajectory group included 30.9% of youth with sharply rising levels between 12 and 15 years, followed by high levels of symptoms between 15 and 20 years. The second trajectory group included 69.1% of youth with low and stable levels of symptoms between 12 and 20 years. Sex-specific models indicated that the proportion of girls in the high trajectory group was 1.3 times higher than the proportion of boys (42.8% girls vs. 32.3% boys). Trajectories of SCOFF items were similar for loss-of-control eating, feeling overweight, and attributing importance to food. The weight loss item had a different developmental pattern, increasing between 12 and 15 years and then decreasing between 17 and 20 years.

CONCLUSIONS

The largest increase in eating disorder symptoms in adolescence is between the ages of 12 and 15 . Yet, most prevention programs start after 15 years of age. Our findings suggest that, unlike common practices, eating disorder prevention programs should aim to start before puberty.

Maternal depressive symptoms and children's cognitive school readiness: the role of gene-environment interplay

Maternal depressive symptoms are a robust risk factor for poor cognitive outcomes in children, yet the role of gene-environment interplay in this association is not well understood. The objective of this study was to evaluate gene-environment interaction in the association between maternal depressive symptoms and children's cognitive school readiness. Data come from a population-based birth cohort of 538 twin pairs. Maternal depressive symptoms were self-reported (Centre for Epidemiologic Studies Depression Scale) when children were aged 6 and 18 months (a mean score was used). Children's cognitive school readiness was assessed using the Lollipop Test when children were aged 5 years. Analyses were conducted with structural equation modeling. Maternal depressive symptoms were correlated with children's cognitive school readiness (r = -0.10). Shared environmental factors explained most of the variance in children's cognitive school readiness (52%). The remaining variance was accounted for by genetic (30%) and nonshared environmental factors (18%). As the level of maternal depressive symptoms increased, the relative contribution of nonshared environmental factors to the variance in children's cognitive school readiness increased (0.14 [95% CI: 0.04 to 0.24]), whereas the relative contribution of genetic factors decreased (-0.28 [-0.64 to 0.08]). In contexts of elevated maternal depressive symptoms, environmental - and potentially modifiable - factors may be especially important for shaping children's cognitive outcomes. This suggests that interventions to improve the early childhood environment of children exposed to maternal depressive symptoms may improve their cognitive outcomes.

The Associations Between Child-Care Services During the Preschool Years and High School Graduation: A 20-Year Longitudinal Population-Based Study

OBJECTIVE

Together with family factors, early care and education (ECE) services were shown to improve school readiness in kindergarten. However, it is not clear whether better school readiness at age 6 years translates into higher rates of high school graduation years later. Our objective was therefore to investigate the long-term associations between the use of ECE and high school graduation while considering the sex of the child and the socioeconomic status of the parents as moderators.

METHODS

Participants were children from the Quebec Longitudinal Study on Child Development (QLSCD) born in 1997 to 1998 (N = 2001). Intensity and type of ECE exposure were measured from age 5 months to 5 years. Administrative records were used to determine whether students had obtained a high school diploma by age 20 years. Factors explaining differences in the profiles of ECE users were controlled using propensity score weights.

RESULTS

Twenty-two percent of students did not have a high school diploma by age 20 years. Compared with children never exposed to center-based care, those exposed early (i.e., before toddlerhood) had better odds of graduating from high school (odds ratio = 1.49) after controlling for confounding factors. Late exposure to center-based care was not related to high school graduation rates.

CONCLUSION

Exposure to regulated and center-based ECE on a regular basis from toddlerhood to school entry was associated with higher rates of high school graduation. Regulated center-based ECE at the population level may improve rates of high school graduation.

Childhood factors associated with suicidal ideation among South African youth: A 28-year longitudinal study of the Birth to Twenty Plus cohort

BACKGROUND

Although early life factors are associated with increased suicide risk in youth, there is a dearth of research on these associations for individuals growing up in disadvantaged socioeconomic contexts, particularly in low- and middle-income countries (LMICs). We documented the association between individual, familial, and environmental factors in childhood with suicidal ideation among South African youth.

METHODS AND FINDINGS

We used data from 2,020 participants in the Birth to Twenty Plus (Bt20+) study, a South African cohort following children born in Soweto, Johannesburg from birth (1990) to age 28 years (2018). Suicidal ideation was self-reported at ages 14, 17, 22, and 28 years, and the primary outcome of interest was suicidal ideation reported at any age. We assessed individual, familial, and socioeconomic characteristics at childbirth and during infancy, adverse childhood experiences (ACEs) between ages 5 and 13 years, and externalizing and internalizing problems between 5 and 10 years. We estimated odds ratios (ORs) of suicidal ideation for individuals exposed to selected childhood factors using logistic regression. Lifetime suicidal ideation was reported by 469 (23.2%) participants, with a 1.7:1 female/male ratio. Suicidal ideation rates peaked at age 17 and decreased thereafter. Socioeconomic adversity, low birth weight, higher birth order (i.e., increase in the order of birth in the family: first, second, third, fourth, or later born child), ACEs, and childhood externalizing problems were associated with suicidal ideation, differently patterned among males and females. Socioeconomic adversity (OR 1.13, CI 1.01 to 1.27, P = 0.031) was significantly associated with suicidal ideation among males only, while birth weight (OR 1.20, CI 1.02 to 1.41, P = 0.03), ACEs (OR 1.11, CI 1.01 to 1.21, P = 0.030), and higher birth order (OR 1.15, CI 1.07 to 1.243, P < 0.001) were significantly associated with suicidal ideation among females only. Externalizing problems in childhood were significantly associated with suicidal ideation among both males (OR 1.23, 1.08 to 1.40, P = 0.002) and females (OR 1.16, CI 1.03 to 1.30, P = 0.011). Main limitations of the study are the high attrition rate (62% of the original sample was included in this analysis) and the heterogeneity in the measurements of suicidal ideation.

CONCLUSIONS

In this study from South Africa, we observed that early life social and environmental adversities as well as childhood externalizing problems are associated with increased risk of suicidal ideation during adolescence and early adulthood.

Childhood psychopathic traits and mental health outcomes in adolescence: compensatory and protective effects of positive relationships with parents and teachers

We identified mental health outcomes associated with specific developmental trajectories of psychopathic traits across childhood and tested whether positive relationships with parents and teachers have compensatory or protective effects. Participants were 1401 children (52.82% girls) from the Quebec Longitudinal Study of Child Development with available data on teacher-reported psychopathic traits (ages 6-12 years) and self-reported mental health outcomes (ages 15-17 years). Parents and teachers reported their levels of positive relationship with the child (ages 6-8 and 10-12 years). Trajectories of psychopathic traits (High-stable, Increasing, Decreasing, and Low-stable) were included as predictors of mental health outcomes (e.g., conduct disorder, anxiety) in structural equation models controlling for child sex, family SES, and earlier psychopathology. Compensatory effects were tested via main effects of positive relationships and protective effects were tested via their interactive effects with trajectories memberships. When compared to the Low-stable trajectory of psychopathic traits, the High-stable, Increasing, and Decreasing trajectories were associated with distinct sets of mental health outcomes, with children from the Increasing trajectory being at higher risk for both externalizing and internalizing psychopathology. Positive relationships with parents and teachers only partially compensated for these effects. Findings suggest that clinicians cannot expect the detrimental effects associated with psychopathic traits to be entirely prevented by children's positive relationships with parents and/or teachers. This study reinforces the importance of providing intensive preventive interventions to elementary school children with high levels of psychopathic traits to prevent the long-term negative consequences associated with these traits.

COVID-19 and the impacts on youth mental health: emerging evidence from longitudinal studies

Several experts have warned that the current coronavirus disease 2019 (COVID-19) pandemic and associated confinement measures may have taken a devastating toll on youth mental health. While the COVID-19 pandemic has certainly created important challenges for children and youth, these claims vastly rely on cross-sectional data collected during the pandemic, from which it is difficult to draw firm conclusions. In this commentary, we offer a critical appraisal of the evidence from emerging longitudinal studies spanning the pre- and intra-pandemic period with a focus on internalizing and externalizing disorders, suicidality, eating disorders and substance use. We also discuss important research considerations in the monitoring of the long-term impacts of the COVID-19 pandemic on youth mental health as well as promising interventions to help mitigate potential long-lasting consequences of this unprecedented public health crisis.

Medical conditions and Attention-Deficit/Hyperactivity Disorder symptoms from early childhood to adolescence

The comorbidity between physical and mental health conditions is challenging and frequently goes unrecognized in practice. Associations between Attention-Deficit/Hyperactivity Disorder (ADHD) and physical conditions have been reported in youth. However, prior research failed to: (1) address the patterns of associations in early childhood, middle childhood, and adolescence within the same population sample; (2) consider a large set of physical disorders at the same time; (3) take confounders into account. Our goal was to assess the associations between ADHD symptoms and a broad set of physical conditions across developmental periods. This birth cohort study (n = 2057) is the first to explore the associations between ADHD and a wide range of medical conditions by encompassing the whole early development from 5 months to 17 years in the same sample and relying on innovative network analyses. We found significant associations between ADHD symptoms and several physical conditions, some of which were observed in early childhood, middle childhood, and adolescence (e.g., asthma, sleep problems) or were confounded by socioeconomic status or psychiatric comorbidities (e.g., body mass index, dental caries). The study calls for an effective integrated care model encompassing mental and general healthcare across the developmental period.

A three-factor model of common early onset psychiatric disorders: temperament, adversity, and dopamine

Commonly comorbid early onset psychiatric disorders might reflect the varying expression of overlapping risk factors. The mediating processes remain poorly understood, but three factors show some promise: adolescent externalizing traits, early life adversity, and midbrain dopamine autoreceptors. To investigate whether these features acquire greater predictive power when combined, a longitudinal study was conducted in youth who have been followed since birth. Cohort members were invited to participate based on externalizing scores between 11 to 16 years of age. At age 18 (age 18.5 ± 0.6 y.o.), 52 entry criteria meeting volunteers had a 90-min positron emission tomography scan with [¹⁸F]fallypride, completed the Childhood Trauma Questionnaire, and were assessed with the Structured Clinical Interview for DSM-5. The three-factor model identified those with a lifetime history of DSM-5 disorders with an overall accuracy of 90.4% (p = 2.4 × 10^-5) and explained 91.5% of the area under the receiver operating characteristic curve [95% CI: .824, 1.000]. Targeting externalizing disorders specifically did not yield a more powerful model than targeting all disorders (p = 0.54). The model remained significant when including data from participants who developed their first disorders during a three-year follow-up period (p = 3.5 × 10^-5). Together, these results raise the possibility that a combination of temperamental traits, childhood adversity, and poorly regulated dopamine transmission increases risk for diverse, commonly comorbid, early onset psychiatric problems, predicting this susceptibility prospectively.

Longitudinal Trajectories of Food Insecurity in Childhood and Their Associations With Mental Health and Functioning in Adolescence

IMPORTANCE

Household food insecurity has been associated with mental health problems in children independently of family income and other confounders. It is unclear whether food insecurity during childhood is also associated with mental health and functioning during adolescence.

OBJECTIVE

To evaluate longitudinal trajectories of household food insecurity during the first 13 years of life, characteristics associated with these trajectories, and the associations of the trajectories with externalizing, internalizing, substance use, and social adjustment problems at 15 years of age.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included participants from the Québec Longitudinal Study of Child Development, a cohort of 2120 children born in Québec, Canada, in 1997 and 1998 and followed up annually or biannually from 5 months to 15 years of age (1998-2013). Data were analyzed from November 2020 to October 2021.

EXPOSURES

When children were aged 1.5, 4, 8, 10, 12, and 13 years, mothers reported whether a family member experienced hunger because the family had run out of food or money to buy food in the past 12 months.

MAIN OUTCOMES AND MEASURES

Group-based trajectory modeling was used to identify differential exposure to food insecurity from 1.5 to 13 years according to logit functions of age. At 15 years of age, adolescents completed validated questionnaires assessing externalizing, internalizing, substance use, and social adjustment problems. Associations between trajectories of food insecurity and outcomes were assessed using linear regressions.

RESULTS

A total of 2032 individuals were included in the analyses of trajectories of food insecurity (1026 [50.5%] male) and 1441 in the analysis of the association with outcomes at 15 years of age (752 [52.2%] female). Two trajectories of food insecurity were identified between 1.5 and 13 years of age: high risk (73 children [3.6%]) and low risk (1959 children [96.4%]). At 5 months, the high-risk and low-risk groups differed in household characteristics including income insufficiency (58 [80.6%] vs 405 [21.0%]), single parenthood (21 [29.2%] vs 135 [6.9%]), and parental history of depression (mothers: 30 [43.5%] vs 411 [21.7%]; fathers: 12 [32.4%] vs 209 [13.5%]). The high-risk trajectory from 1.5 to 13 years of age was associated with cannabis use (β, 0.47; 95% CI, 0.12-0.81), peer bullying (β, 0.43; 95% CI, 0.08-0.77), and dropout potential (β, 0.38; 95% CI, 0.03-0.68) at 15 years of age after adjustment for sex, household income insufficiency, and parental mental health.

CONCLUSIONS AND RELEVANCE

In this cohort study, few children experienced a persistent high risk of food insecurity, which was associated with psychosocial problems later in adolescence after adjustment for confounders including low income. Early identification of risk for food insecurity may guide the delivery of tailored interventions to improve functioning in adolescence.

Identifying environmental pathways between irritability during childhood and suicidal ideation and attempt in adolescence: findings from a 20-year population-based study

BACKGROUND

Irritable children are at increased risk of suicidal ideation and suicide attempt, but the underlying environmental mechanisms accounting for these associations are largely unknown. We aimed to investigate the mediating role of peer victimization and harsh parenting in the association between childhood irritability and adolescent suicidal ideation and attempt.

METHOD

N = 1,483 participants from the Québec Longitudinal Study of Child Development followed up from 5 months until 20 years of age (2018) with annual or biannual assessments. Irritability was operationalized using assessments of teacher-reported temper tantrums and reactive aggression. Suicidal ideation and suicide attempt at ages 13, 15, 17, and 20 years were self-reported. Peer victimization (self-reported at age 13) and harsh parenting (mothers reported at age 13) were considered as potential mediators.

RESULTS

We identified four trajectories of teacher-reported irritability symptoms from 6 to 12 years: low (74.8%), rising (12.9%), declining (7.3%), and persistent (4.9%). In adjusted models, children in the persistent and rising trajectories had, respectively, 2.81-fold (CI, 1.27-6.22) and 2.14-fold (CI, 1.20-3.81) increased odds of suicide attempt in adolescence, but not suicidal ideation. We found that a significant proportion of the association between irritability trajectories and suicide attempt was mediated by peer victimization (33% and 35% for rising and persistent, respectively), but there was no mediation via harsh parenting.

CONCLUSIONS

Our findings suggest that peer victimization may be a key mechanism explaining the increased suicide attempt risk of children presenting with persistently high or increasing irritability. Interventions to reduce peer victimization may be helpful to reduce suicide risk among irritable children.

Polygenic scores differentially predict developmental trajectories of subtypes of social withdrawal in childhood

BACKGROUND

Children who consistently withdraw from social situations face increased risk for later socioemotional difficulties. Twin studies indicate that genetic factors substantially account for the persistence of social withdrawal over time. However, the molecular genetic etiology of chronic courses of social wariness and preference for solitude, two dimensions of social withdrawal, remains undocumented. The objectives of the present study were (a) to identify high-risk trajectories for social wariness and preference for solitude in childhood and (b) to examine whether falling on these high-risk trajectories can be predicted by specific polygenic scores for mental health traits and disorders and by a general polygenic predisposition to these traits.

METHODS

Teachers evaluated 971 genotyped children at five occasions (age 6 to 12 years) from two prospective longitudinal studies, the Quebec Newborn Twin Study and the Quebec Longitudinal Study of Child Development. Developmental trajectories for social wariness and preference for solitude were identified. We tested whether polygenic scores for attention deficit hyperactivity disorder, autism spectrum disorder, depression, loneliness, and subjective well-being, as well as a general mental health genetic risk score derived across these traits, were associated with the developmental trajectories.

RESULTS

Polygenic scores differentially predicted social wariness and preference for solitude. Only the loneliness polygenic score significantly predicted the high trajectory for social wariness. By contrast, the general mental health genetic risk score factor was associated with the trajectory depicting high-chronic preference for solitude.

CONCLUSIONS

Distinct associations were uncovered between the polygenic scores, social wariness, and preference for solitude.

Depression and anxiety symptoms in young adults before and during the COVID-19 pandemic: evidence from a Canadian population-based cohort

BACKGROUND

Concerns have been raised that the COVID-19 pandemic could increase risk for adverse mental health outcomes, especially in young adults, a vulnerable age group. We investigated changes in depression and anxiety symptoms (overall and severe) from before to during the pandemic, as well as whether these changes are linked to COVID-19-related stressors and pre-existing vulnerabilities in young adults followed in the context of a population-based cohort.

METHOD

Participants (n = 1039) from the Quebec Longitudinal Study of Child Development reported on their depression (Centre for Epidemiological Studies Depression Scale, short form) and anxiety (General Anxiety Disorder-7 Scale) symptoms and completed a COVID-19 questionnaire during the first wave of the COVID-19 pandemic in the summer of 2020 (age 22 years). Assessments at age 20 (2018) were used to estimate pre-pandemic depression and anxiety symptom severity.

RESULTS

While mean levels of depression and anxiety symptoms did not change from before to during the first wave of the COVID-19 pandemic (e.g., the mean of depressive symptoms was 9.30 in 2018 and 9.59 in 2020), we observed a slight increase in rates of severe depression (scores ≥ 21) from before (6.1%) to during (8.2%) the pandemic. Most COVID-19-related variables (e.g., loss of education/occupation, frequent news-seeking) - except living alone - and most pre-existing vulnerabilities (e.g., low SES, low social support) were not associated with changes in depression or anxiety symptoms. However, results varied as a function of pre-pandemic levels of depression and anxiety: depression and anxiety symptoms increased among adults with the lowest levels of symptoms before the pandemic, while they decreased among those with the highest levels of symptoms, possibly reflecting a regression to the mean.

CONCLUSIONS

Depression and anxiety symptoms in young adults from Québec in Summer 2020 were mostly comparable to symptoms reported in 2018. Most COVID-19-related stressors and pre-existing vulnerabilities were not associated with changes in symptoms, except living alone and pre-existing symptoms of depression and anxiety. However, the increased rate of severe depression warrants further investigation.

Analysis of Maternal Postnatal Depression, Socioeconomic Factors, and Offspring Internalizing Symptoms in a Longitudinal Cohort in South Africa

IMPORTANCE

Few studies from low-and-middle income countries have investigated long-term associations between maternal postnatal depression and offspring internalizing (ie, depressive and anxiety) symptoms, and none have investigated interactions in this association.

OBJECTIVE

To investigate the association between maternal postnatal depression and offspring internalizing symptoms from adolescence to adulthood and the interaction with exposure to socioeconomic adversity and with the child's sex.

DESIGN, SETTING, AND PARTICIPANTS

This secondary analysis used data from Birth to Twenty Plus (BT20+), a prospective birth cohort study of children born in Soweto, South Africa, and followed up until age 28 years. Data were collected from 1990 to 2018, and data were analyzed for this study from February 16 through December 15, 2020.

EXPOSURES

Maternal postnatal depression self-reported by mothers 6 months after childbirth.

MAIN OUTCOMES AND MEASURES

The main outcome was offspring internalizing symptoms, assessed at offspring ages 14 years, 22 years, and 28 years and modeled longitudinally. Participants with the highest probability of experiencing high internalizing symptoms (ie, those in the top 20% of the distribution) from age 14 to 28 years were categorized as belonging to the high internalizing symptoms trajectory (vs the low trajectory). Socioeconomic adversity was measured with an index (continuous variable) including low maternal education, household crowding, low assets, and low maternal age. This variable was further stratified into more than 1 SD above the mean index, more than 1 SD below the mean index, and from 1 SD below to 1 SD above the mean index to conduct subgroup analyses. Associations were investigated using multivariable regression models.

RESULTS

Among 1087 participants born in Soweto, South Africa (543 [50.0%] male participants; 544 [50.0%] female participants), 118 individuals (10.8%) showed a high trajectory of internalizing symptoms from age 14 to 28 years vs 969 individuals (89.1%) with a low trajectory. Children exposed to maternal postnatal depression had statistically significantly increased odds of following the high trajectory (adjusted odds ratio [aOR] per 1-SD increase in maternal postnatal depression, 1.20; 95% CI, 1.02-1.41). This increase in odds differed by exposure to socioeconomic adversity and by child sex: for male participants, the increase in odds was greater in a context of higher vs lower socioeconomic adversity (eg, for >1 SD above the mean: aOR, 3.28; 95% CI, 1.06-10.14 vs for >1 SD below the mean: aOR, 0.98; 95% CI, 0.64-1.50; P for interaction = .12), while for female participants, the increase in odds was greater in a context of lower vs higher socioeconomic adversity (eg, for >1 SD below the mean: aOR, 1.82; 95 % CI, 1.12-2.98 vs for >1 SD above the mean: aOR, 0.59; 95 % CI, 0.30-1.17; P for interaction = .002) (P for 3-way interaction = .003).

CONCLUSIONS AND RELEVANCE

This study found that postnatal depression was associated with higher odds of persistently increased internalizing symptoms among offspring from adolescence to adulthood in a middle-income country, with variation by socioeconomic adversity and sex. These findings suggest that better understanding of these associations is needed to implement targeted interventions and maximize the impact of public health initiatives aimed at breaking the intergenerational transmission of mental health problems.