Cannabis use, depression and suicidal ideation in adolescence: direction of associations in a population based cohort

BACKGROUND

To clarify the direction of the association between frequency of cannabis use, depressive symptoms and suicidal ideation from 15 to 20 years using cross-lagged analyses.

METHOD

We included 1606 adolescents from the province of Québec followed since 1997 with information on frequency of cannabis use (none/monthly/weekly), depression (defined as being in the top 10% symptoms) and serious suicidal ideation at ages 15, 17 and 20 years.

RESULTS

The prevalence of weekly cannabis use increased from 7.0% at age 15 years to 15.6% by age 20 years. Adolescents who reported using cannabis weekly at one age were 11 to 15 times more likely to continue using cannabis over time. In longitudinal cross-lagged analyses, weekly cannabis use at age 15 was associated with greater odds (OR=2.19, 95% CI=1.04-4.58) of suicidal ideation two years later. However, other substance use (alcohol, tobacco, other drugs) fully explained this association. Further, depression predicted subsequent weekly cannabis use, even after adjusting for comorbid other substance use (eg, for depression at 15 years predicting cannabis use at 17 years: OR=2.30, 95% CI=1.19-4.43).

LIMITATIONS

Quantity of cannabis consumed was not measured.

CONCLUSION

Findings suggest that depressive symptoms in adolescence may represent a risk factor for weekly cannabis consumption, which once initiated is likely to remain chronic. Weekly cannabis use increased risk for suicidal ideation, but not independently from other substance use including alcohol, tobacco and other drugs.

Cybervictimization in adolescence and its association with subsequent suicidal ideation/attempt beyond face-to-face victimization: a longitudinal population-based study

BACKGROUND

Cross-sectional associations have been documented between cybervictimization and suicidal risk; however, prospective associations remain unclear.

METHODS

Participants were members of the Quebec Longitudinal Study of Child Development (QLSCD), a prospective birth cohort of 2,120 individuals followed from birth (1997/98) to age 17 years (2014/15). Cybervictimization and face-to-face victimization experienced since the beginning of the school year, as well as serious suicidal ideation and/or suicide attempt were self-reported at ages 13, 15 and 17 years.

RESULTS

In cross-sectional analyses at 13, 15 and 17 years, adolescents cybervictimized at least once had, respectively, 2.3 (95% CI = 1.64-3.19), 4.2 (95% CI = 3.27-5.41) and 3.5 (95% CI = 2.57-4.66) higher odds of suicidal ideation/attempt after adjusting for confounders including face-to-face victimization, prior mental health symptoms and family hardship. Sensitivity analyses suggested that cybervictimization only and both cyber- and face-to-face victimization were associated with a higher risk of suicidal ideation/attempt compared to face-to-face victimization only and no victimization; however, analyses were based on small n. In prospective analyses, cybervictimization was not associated with suicidal ideation/attempt 2 years later after accounting for baseline suicidal ideation/attempt and other confounders. In contrast, face-to-face victimization was associated with suicidal ideation/attempt 2 years later in the fully adjusted model, including cybervictimization.

CONCLUSIONS

The cross-sectional association between cybervictimization and suicidal ideation/attempt is independent from face-to-face victimization. The absence of a prospective association suggested short-term effects of cybervictimization on suicidal ideation/attempt.

Child Care Attendance and Educational and Economic Outcomes in Adulthood

OBJECTIVES

To test associations between onset of formal child care (in infancy or as a toddler), high school graduation, and employment earnings from ages 18 to 35 years.

METHODS

A 30-year prospective cohort follow-up study, with linkage to government administrative databases (N =3020). Exposure included formal child care, if any, by accredited caregivers in centers or residential settings at ages 6 months and 1, 1.5, 2, 3, and 4 years. A propensity score analysis was conducted to control for social selection bias.

RESULTS

Of 2905 participants with data on child care use, 59.4% of male participants and 78.5% of female participants completed high school by age 22 to 23. Mean income at last follow-up (n = 2860) was $47 000 (Canadian dollars) (SD = 37 700) and $32 500 (SD = 26 800), respectively. Using group-based trajectory modeling, we identified 3 groups: formal child care onset in infancy (∼6 months), formal child care onset as a toddler (after 2.5 years), and never exposed. After propensity score weighting, boys with child care started in infancy had greater odds of graduating than those never exposed (odds ratio [OR] 1.39; 95% confidence interval [CI]: 1.18-1.63; P < .001). Boys attending child care had reduced odds of low income as young adults (infant onset: OR 0.60 [95% CI: 0.46-0.84; P < .001]; toddler onset: OR 0.63 [95% CI: 0.45-0.82; P < .001]). Girls' graduation rates and incomes revealed no significant association with child care attendance.

CONCLUSIONS

For boys, formal child care was associated with higher high school completion rates and reduced risk of adult poverty. Benefits for boys may therefore extend beyond school readiness, academic performance, and parental workforce participation.

Mental Health Problems and Risk of Suicidal Ideation and Attempts in Adolescents

BACKGROUND

Obtaining recent estimates of the prevalence of suicide-related outcomes across adolescence and its associated mental health problems (MHPs) is important for clinical practice. We estimated the prevalence of suicide-related outcomes at ages 13, 15, 17, and 20 years (2011-2018) in a contemporary population-based cohort and documented associations with MHPs throughout adolescence.

METHODS

Data came from 1618 participants in the Québec Longitudinal Study of Child Development. Internalizing (depression and anxiety) and externalizing (oppositional/defiance, conduct issues, and attention deficit and/or hyperactivity) MHPs were assessed with validated questionnaires. Outcomes were self-reported past-year passive and serious suicidal ideation and suicide attempt.

RESULTS

Lifetime prevalence of passive suicidal ideation (13-17 years old), serious suicidal ideation, and suicide attempt (13-20 years old) were 22.2%, 9.8%, and 6.7%, respectively. Prevalence was twice as high for females as for males. Overall, rates of passive (15-17 years old; 11.8%-18.4%) and serious ideation (13-20 years old; 3.3%-9.5%) increased over time but were stable for attempt (13-20 years old; 3.5%-3.8%). In univariable analyses, all MHPs were associated with suicide-related outcomes at all ages (risk rate ratio range: 2.57-3.10 [passive ideation] and 2.10-4.36 [suicide attempt]), and associations were similar for male and female participants (sex interaction P > .05). Magnitude of associations were generally stronger for more severe suicide-related outcomes (passive ideation < serious ideation < attempt). In multivariable analyses, internalizing problems were associated with suicidal ideation, whereas both depressive and conduct symptoms were associated with attempt.

CONCLUSIONS

Suicidal ideation and attempt were common, especially for females and youth presenting with depressive and conduct problem symptoms. Clinicians should systematically assess suicidal risk in teenagers, especially in those presenting with MHPs.

Contribution of genes and environment to the longitudinal association between childhood impulsive-aggression and suicidality in adolescence

BACKGROUND

Population-based and family studies showed that impulsive-aggression predicts suicidality; however, the underlying etiological nature of this association is poorly understood. The objective was to determine the contribution of genes and environment to the association between childhood impulsive-aggression and serious suicidal ideation/attempt in young adulthood.

METHODS

N = 862 twins (435 families) from the Quebec Newborn Twin Study were followed up from birth to 20 years. Repeated measures of teacher-assessed impulsive-aggression were modeled using a genetically informed latent growth model including intercept and slope parameters reflecting individual differences in the baseline level (age 6 years) and in the change (increase/decrease) of impulsive-aggression during childhood (6 to 12 years), respectively. Lifetime suicidality (serious suicidal ideation/attempt) was self-reported at 20 years. Associations of impulsive-aggression intercept and slope with suicidality were decomposed into additive genetic (A) and unique environmental (E) components.

RESULTS

Additive genetic factors accounted for an important part of individual differences in impulsive-aggression intercept (A = 90%, E = 10%) and slope (A = 65%, E = 35%). Genetic (50%) and unique environmental (50%) factors equally contributed to suicidality. We found that 38% of the genetic factors accounting for suicidality were shared with those underlying impulsive-aggression slope, whereas 40% of the environmental factors accounting for suicidality were shared with those associated with impulsive-aggression intercept. The genetic correlation between impulsive-aggression slope and suicidality was 0.60, p = .027.

CONCLUSIONS

Genetic and unique environmental factors underlying suicidality significantly overlap with those underlying childhood impulsive-aggression. Future studies should identify putative genetic and environmental factors to inform prevention.

Maternal depression in early childhood and child emotional and behavioral outcomes at school age: examining the roles of preschool childcare quality and current maternal depression symptomatology

Recent studies have shown that the association between maternal depression and child outcome can be moderated by children's experience of childcare (e.g., daycare) during early childhood (0-5 years). We also know that maternal depression in the child's early years has long-term associations with child development. However, the moderating role of childcare quality on long-term associations between maternal depression and child outcome has not been thoroughly investigated. This article examined longitudinal associations between probable maternal depression (PMD) during early childhood (0-5 years) and childcare quality on children's emotional and behavioral development at the age of 7-8 years (N = 207). Childcare quality was evaluated through observations within the settings. PMD during early childhood was assessed using complementary information from interviews conducted with the mother and current maternal symptoms were assessed using the Center for Epidemiologic Studies Depression Scale. Internalizing and externalizing behaviors were reported by the mother, father and the child at age 7-8 years. Results indicate that when mothers reported clinically relevant depression in early childhood, 7-8-year-old children demonstrate fewer behavioral problems if they attended a higher quality childcare setting. The moderating role of childcare quality remained after considering current maternal depression symptoms. Therefore, it is important to ensure high-quality childcare during early childhood to optimize child development.

Early Childhood Factors Associated With Peer Victimization Trajectories From 6 to 17 Years of Age

OBJECTIVES

To describe (1) the developmental trajectories of peer victimization from 6 to 17 years of age and (2) the early childhood behaviors and family characteristics associated with the trajectories.

METHODS

We used data from 1760 children enrolled in the Quebec Longitudinal Study of Child Development, a population-based birth cohort. Participants self-reported peer victimization at ages 6, 7, 8, 10, 12, 13, 15, and 17 years. Participants' behavior and family characteristics were measured repeatedly between ages 5 months and 5 years.

RESULTS

We identified 4 trajectories of peer victimization from 6 to 17 years of age: low (32.9%), moderate-emerging (29.8%), childhood-limited (26.2%), and high-chronic (11.1%). Compared with children in the low peer victimization trajectory, children in the other 3 trajectories were more likely to exhibit externalizing behaviors in early childhood, and those in the high-chronic and moderate-emerging trajectories were more likely to be male. Paternal history of antisocial behavior was associated with moderate-emerging (odds ratio [OR] = 1.54; 95% confidence interval [CI] = 1.09-2.19) and high-chronic (OR = 1.93; 95% CI = 1.25-2.99) relative to low peer victimization. Living in a nonintact family in early childhood was associated with childhood-limited (OR = 1.48; 95% CI = 1.11-1.97) and high-chronic (OR = 1.59; 95% CI = 1.09-2.31) relative to low peer victimization.

CONCLUSIONS

Early childhood externalizing behaviors and family vulnerabilities were associated with the development of peer victimization. Some children entered the cascade of persistent peer victimization at the beginning of primary school. Support to these children and their families early in life should be an important component of peer victimization preventive interventions.

Examining the impact of a social skills training program on preschoolers' social behaviors: a cluster-randomized controlled trial in child care centers

Background

Preschoolers regularly display disruptive behaviors in child care settings because they have not yet developed the social skills necessary to interact prosocially with others. Disruptive behaviors interfere with daily routines and can lead to conflict with peers and educators. We investigated the impact of a social skills training program led by childcare educators on children’s social behaviors and tested whether the impact varied according to the child’s sex and family socio-economic status.

Methods

Nineteen public Child Care Centers (CCC, n = 361 children) located in low socio-economic neighborhoods of Montreal, Canada, were randomized into one of two conditions: 1) intervention (n = 10 CCC; 185 children) or 2) wait list control (n = 9 CCC; 176 children). Educators rated children’s behaviors (i.e., disruptive and prosocial behaviors) before and after the intervention. Hierarchical linear mixed models were used to account for the nested structure of the data.

Results

At pre-intervention, no differences in disruptive and prosocial behaviors were observed between the experimental conditions. At post-intervention, we found a significant sex by intervention interaction (β intervention by sex = − 1.19, p = 0.04) indicating that girls in the intervention condition exhibited lower levels of disruptive behaviors compared to girls in the control condition (f2 effect size = − 0.15). There was no effect of the intervention for boys.

Conclusions

Girls may benefit more than boys from social skills training offered in the child care context. Studies with larger sample sizes and greater intervention intensity are needed to confirm the results.

Trial registration

Current clinical trial number is ISRCTN84339956 (Retrospectively registered in March 2017). No amendment to initial protocol.

Adolescent internalizing symptoms: The importance of multi-informant assessments in childhood

BACKGROUND

Childhood internalizing symptoms can be associated with adolescent internalizing symptoms, but only a small proportion of symptomatic children are at long-term risk. Our objectives were to (1) distinguish between typical and atypical levels of internalizing symptoms using mother- and teacher-assessments and (2) test the association between childhood internalizing symptoms and adolescent generalized anxiety, depression, and social phobia symptoms in boys and girls.

METHODS

Multi-trajectory models were used to estimate the evolution of mother- and teacher-reported internalizing symptoms across childhood (1.5 to 12 years) in a large population-based cohort (n = 1431). Multiple linear regression models were implemented to estimate the association between childhood group membership of internalizing symptoms and self-reported specific internalizing symptoms at 15 years by sex.

RESULTS

Five groups of childhood internalizing symptoms were identified: Mother & teacher low (22.6%), Mother moderate/teacher low (37.9%), Mother moderate/teacher high (18.3%), Mother high/teacher low (11.8%) and Mother & teacher high (9.5%). Multiple linear regression models showed that compared to the low group, (1) boys in the high group reported higher social phobia symptoms (p = 0.04), (2) girls in the high group reported higher depression (p = 0.01) and generalized anxiety (p < 0.01) symptoms, and (3) girls in the moderate/high group reported higher generalized anxiety symptoms (p = 0.02) in adolescence.

LIMITATIONS

The main limitation is that mothers' and teachers' assessments mostly covered different developmental periods.

CONCLUSIONS

A multi-informant assessment of childhood internalizing symptoms improves adolescent specific internalizing symptoms identification in a general population sample over reliance on a single informant.

Association Between Peer Victimization and Parasomnias in Children: Searching for Relational Moderators

This cross-sectional study examined the moderating role of support from three key figures (mothers, teachers, friends) in the association between peer victimization and parasomnias in childhood. The sample consisted of 1150 children aged 8 years who attended elementary school. Controlling for potential confounders, hierarchical multiple regressions revealed that peer victimization was associated with a higher level of parasomnias, equally for both girls and boys. However, for girls, the predictive association of peer victimization with parasomnias was moderated by the level of support in relationships with either their parents, their teachers, or their friends. The findings suggest that somatic symptoms such as sleep problems may be a first indicator that a child is being bullied. Because parents, teachers as well as friends can play a key role in preventing the development of parasomnias, it may be useful to help bullied children develop strong bonds within at least one of these relationships.

Developmental trajectories of childhood symptoms of hyperactivity/inattention and suicidal behavior during adolescence

Hyperactive/inattentive symptoms (ADHD symptoms) are associated with suicidal behavior in clinical studies, but there is still a lack of population-based longitudinal investigations on the developmental aspects of this association. Additionally, it is unclear whether the association is similar for boys and girls. The objectives of the study were to test the association between the ADHD symptoms during childhood and suicidal ideation and attempt during adolescence, and to investigate sex differences. 1407 children from the Québec Longitudinal Study of Child Development were followed up from 5 months to 17 years of age. We used teacher-reports of ADHD symptoms from 6 to 12 years, and self-report of suicidal ideation and attempt at 13, 15, and 17 years. We identified three ADHD symptoms trajectories: low (boys: 32.2%, girls: 48.7%), moderate (boys: 44.6%; girls: 42.2%) and high (boys: 23.2%; girls: 9.1%). Compared to boys on a low trajectory, boys on a moderate trajectory were at higher risk for suicidal ideation (OR 4.2, 95% CI 1.2-14.8), and boys on a high trajectory were at higher risk for suicide attempts (OR 4.5, 95% CI 1.1-17.9). Girls on moderate or high ADHD symptoms trajectories were not at higher risk for suicidal ideation or attempts than girls on low trajectories. For boys, but not for girls, moderate-to-high ADHD symptoms increased the suicidal risk in adolescence. Interventions with boys showing ADHD symptoms should include a suicide prevention component.

Maternal depressive symptoms and children's cognitive development: Does early childcare and child's sex matter?

BACKGROUND

Maternal depressive symptoms (MDS) have been associated with poorer child cognitive development. Some studies have shown that childcare attendance moderates associations between MDS and child behavior problems, but we do not know if this is the case for children's cognitive development. Furthermore, few studies have evaluated whether associations between MDS and child cognitive development differ for boys and girls at school entry.

METHODS

This study used data from a population-based cohort study (n = 1364) comprising well-validated measures of children's cognitive development including academic readiness and language development in kindergarten and reading and mathematics achievement in first grade. Information on MDS was collected repeatedly from the child's age of 5 months to 5 years and on childcare from 5 months to 4.5 years. Moderation analyses were conducted to evaluate the differential associations of MDS with children's outcomes depending on the type of childcare attended and the child's sex.

RESULTS

Childcare type or child's sex did not moderate associations between MDS and children's cognitive outcomes except for MDS being associated with lower scores on reading achievement in first grade for girls with a very small effect size (sr2 = .003). Childcare attendance was associated with higher scores for children's cognitive development, however these associations disappeared after adjusting for covariates including child, mother and family characteristics. Regardless of MDS and childcare type, boys had, even after adjusting for covariates, lower scores on academic readiness (sr2 = .029) and higher scores on mathematics achievement (sr2 = .004).

CONCLUSIONS

Children's cognitive development at school entry was more strongly associated with maternal education, children's age in kindergarten and number of months of schooling in first grade than MDS. Contrary to associations between MDS and child behavior problems, childcare attendance did not moderate associations between MDS and children's cognitive development at school entry.

Early childhood child care and disruptive behavior problems during adolescence: a 17-year population-based propensity score study

BACKGROUND

Child-care services during early childhood provide opportunities for social interactions that may facilitate children's learning of acceptable social behaviors. Furthermore, they may reduce exposure to family adversity for some children. The aim of this study was to determine whether intensity of exposure to child-care services prior to age 5 years has a beneficial effect on disruptive behavior problems during adolescence, and whether the effect is more pronounced for children from low socioeconomic families.

METHODS

N = 1,588 participants from the Québec Longitudinal Study of Child Development were assessed 14 times from 5 months to 17 years. Intensity of child-care exposure was measured from 5 months to 5 years of age. Main outcomes were self-reported physical aggression and opposition from age 12 to 17 years. Family socioeconomic status (SES) was measured at 5 months. Factors explaining differences in child-care use were controlled using propensity score weights (PSW).

RESULTS

Children exposed to moderate-intensity child-care services (part-time child-care services before 1½ years and full time afterward) reported lower levels of physical aggression (d = -.11, p = .056) and opposition (d = -.14, p = .029) during adolescence compared to children exposed to low-intensity child-care services. A significant child care by SES interaction (p = .017) for physical aggression indicated that the moderate-intensity child-care effect was specific to children from low SES families (d = -.36, p = .002). No interaction with socioeconomic status was found for opposition.

CONCLUSIONS

Moderate-intensity child-care services from infancy to school entry may prevent disruptive behavior during adolescence, especially for disadvantaged children.

Association Between Childhood Behaviors and Adult Employment Earnings in Canada

Importance

Specifying the association between childhood behaviors and adult earnings can inform the development of screening tools and preventive interventions to enhance social integration and economic participation.

Objective

To test the association between behaviors at age 6 years and employment earnings at age 33 to 35 years.

Design, Setting, and Participants

This study obtained data from the Quebec Longitudinal Study of Kindergarten Children, a population-based sample of boys and girls (n = 3020) born in 1980 or 1981 in Quebec, Canada, and followed up from January 1, 1985, to December 31, 2015. The data included behavioral ratings by kindergarten teachers when the children were aged 5 or 6 years and 2013 to 2015 government tax returns of those same participants at age 33 to 35 years. Data were analyzed from September 2017 to December 2018.

Main Outcomes and Measures

Mixed-effects linear regression models were used to test the associations between teacher-rated inattention, hyperactivity, aggression, opposition, anxiety, and prosociality at age 6 years and reported annual earnings on income tax returns at age 33 to 35 years. Participant IQ and family adversity were adjusted for in the analysis.

Results

The study included 2850 participants, with a mean (SD) age of 35.9 (0.29) years, of whom 1470 (51.6%) were male and 2740 (96.2%) were white. The mean (SD) personal earnings at follow-up were US $33 300 ($27 500) for men and $19 400 ($15 200) for women. A 1-unit increase in inattention score at age 6 years (males mean [SD], 2.47 [2.42] vs females mean [SD], 1.67 [2.07]) was associated with a decrease in annual earnings of $1271.49 (95% CI, -1908.67 to -634.30) for male participants and $924.25 (95% CI, -1424.44 to -425.46) for female participants. A combined aggression-opposition score (males mean [SD] 2.22 [2.52] vs females mean [SD], 1.05 [1.73]) was associated with a reduction in earnings of $699.83 (95% CI, -1262.49 to -137.17) for males only, albeit with an effect size roughly half that of inattention. A 1-unit increase in prosociality score (males mean [SD], 6.12 [4.30] vs females mean [SD], 7.90 [4.56]) was associated with an increase in earnings of $476.75 (95% CI, 181.53-771.96) for male participants only. A 1-SD reduction in inattention score at age 6 years would theoretically restore $3077 in annual earnings for male participants and $1915 for female participants.

Conclusions and Relevance

In this large population-based sample of kindergarten children, behavioral ratings at 5-6 years were associated with employment earnings 3 decades later, independent of a person's IQ and family background. Inattention and aggression-opposition were associated with lower annual employment earnings, and prosociality with higher earnings but only among male participants; inattention was the only behavioral predictor of income among girls. Early monitoring and support for children demonstrating high inattention and for boys exhibiting high aggression-opposition and low prosocial behaviors could have long-term advantages for those individuals and society.

Impact of an early childhood intervention on the home environment, and subsequent effects on child cognitive and emotional development: A secondary analysis

The objective of this study was to use secondary data from the Preparing for Life (PFL) trial to test (1) the impact of a prenatal-to-age-five intervention targeting women from a disadvantaged Irish community on the quality of the home environment; (2) whether any identified changes in the home environment explain the positive effects of the PFL program on children’s cognitive and emotional development at school entry which have been identified in previous reports of the PFL trial (ES = .72 and .50, respectively). Pregnant women were randomized into a treatment (home visits, baby massage, and parenting program, n = 115) or control (n = 118) group (trial registration: ISRCTN04631728). The home environment was assessed at 6 months, 1½, and 3 years using the Home Observation for Measurement of the Environment (responsiveness, acceptance, organization, learning material, involvement, variety). Cognitive skills were assessed at 5 years using the British Ability Scales. Emotional problems were teacher-reported at 5 years using the Short Early Development Inventory. Latent growth modeling was used to model changes in the home environment, and mediation analyses to test whether those changes explained children outcomes. Compared to controls, treatment children were exposed to more stimulating environments in terms of learning material (B = -1.62, p = 0.036) and environmental variety (B = -1.58, p = 0.009) at 6 months, but these differences faded at 3 years. Treatment families were also more likely to accept suboptimal child behaviors without using punishment (acceptance score, B = 1.49, p = 0.048) and were more organized at 3 years (B = 1.08, p = 0.033). None of the changes mediated children’s outcomes. In conclusion, we found that the program positively impacted different home environment dimensions, but these changes did not account for improvements in children’s outcomes. Exploratory analyses suggest that the impact of improvements in the home environment on child outcomes may be limited to specific groups of children. Limitations of the study include the potential lack of generalizability to other populations, the inability to assess the individual treatment components, and sample size restrictions which precluded a moderated mediation analysis.

Development of Aggression Subtypes from Childhood to Adolescence: a Group-Based Multi-Trajectory Modelling Perspective

The persistence of elevated subtypes of aggression beginning in childhood have been associated with long-term maladaptive outcomes. Yet it remains unclear to what extent there are clusters of individuals following similar developmental trajectories across forms (i.e., physical and indirect) and functions (i.e., proactive and reactive) of aggression. We aimed to identify groups of children with distinct profiles of the joint development of forms and functions of aggression and to identify risk factors for group membership. A sample of 787 children was followed from birth to adolescence. Parent and teacher reports, and standardised assessments were used to measure two forms and two functions of aggressive behaviour, between six and 13 years of age along with preceding child, maternal, and family-level risk-factors. Analyses were conducted using a group-based multi-trajectory modelling approach. Five trajectory groups emerged: non-aggressors, low-stable, moderate-engagers, high-desisting, and high-chronic. Coercive parenting increased membership risk in the moderate-engagers and high-chronic groups. Lower maternal IQ increased membership risk in both high-desisting and high-chronic groups, whereas maternal depression increased membership risk in the high-desisting group only. Never being breastfed increased membership risk in the moderate-engagers group. Boys were at greater risk for belonging to groups displaying elevated aggression. Individuals with chronic aggression problems use all subtypes of aggression. Risk factors suggest that prevention programs should start early in life and target mothers with lower IQ. Strategies to deal with maternal depression and enhance positive parenting while replacing coercive parenting tactics should be highlighted in programming efforts.

Association of Behavior in Boys From Low Socioeconomic Neighborhoods With Employment Earnings in Adulthood

Importance

Identifying early childhood behavioral problems associated with economic success/failure is essential for the development of targeted interventions that enhance economic prosperity through improved educational attainment and social integration.

Objective

To test the association between kindergarten teacher-rated assessments of inattention, hyperactivity, opposition, aggression, and prosociality in boys with their employment earnings at age 35 to 36 years as measured by government tax return data.

Design, Setting, and Participants

A 30-year prospective follow-up study analyzing low socioeconomic neighborhoods in Montreal, Quebec, Canada. Boys aged 5 to 6 years attending kindergarten in low socioeconomic neighborhoods were recruited. Teacher-rated behavioral assessments were obtained for 1040 boys. Data were collected from April 1984 to December 2015. Analysis began January 2017.

Main Outcomes and Measures

Mixed-effects linear regression models were used to examine the association between teacher ratings of inattention, hyperactivity, opposition, aggression, and prosociality at age 6 years and individual earnings obtained from government tax returns at age 35 to 36 years. The IQ of the child and family adversity were adjusted for in the analysis.

Results

Complete data were available for 920 study participants (mean age at follow-up was 36.3 years). Mean (SD) personal earnings at follow-up were $28 865.53 ($24 103.45) (range, $0-$142 267.84). A 1-unit increase in inattention (mean [SD], 2.66 [2.34]; range, 0-8) at age 6 years was associated with decrease in earnings at age 35 to 36 years of $1295.13 (95% CI, -$2051.65 to -$538.62), while a unit increase in prosociality (mean [SD], 8.0 [4.96]; range, 0-20) was associated with an increase in earnings of $406.15 (95% CI, $172.54-$639.77). Hyperactivity, opposition, and aggression were not significantly associated with earnings. Child IQ was associated with higher earnings and family adversity with lower earnings in all models. A 1-SD reduction in inattention at age 6 years was associated with a theoretical increase in annual earnings of $3040.41, a similar magnitude to an equivalent increase in IQ.

Conclusions and Relevance

Teacher ratings of inattention and prosociality in kindergarten boys from low socioeconomic neighborhoods are associated with earnings in adulthood after adjustment for hyperactivity, aggression, and opposition, which were not associated with earnings. Interventions beginning in kindergarten that target boys' inattention and enhance prosociality could positively impact workforce integration and earnings.

Cumulative risk and protection effect of serotonergic genes on male antisocial behaviour: results from a prospective cohort assessed in adolescence and early adulthood

BACKGROUND

Heritability of antisocial behaviour is estimated at approximately 50% and involves multiple genes.AimsTo investigate the cumulative genetic effects of 116 single nucleotide polymorphisms mapping to 11 candidate serotonergic genes and antisocial behaviours, in adolescence and in early adulthood.

METHOD

Participants were 410 male members of the Quebec Longitudinal Study of Kindergarten Children, a population-based cohort followed up prospectively from age 6 to age 23. The serotonergic genes were selected based on known physiological processes and prior associations with antisocial behaviours. Antisocial behaviours were self-reported and assessed by using semi-structured interviews in adolescence and in adulthood.

RESULTS

Cumulative, haplotype-based contributions of serotonergic genes conferring risk and protection for antisocial behaviours were detected by using multilocus genetic profile risk scores (MGPRSs) and multilocus genetic profile protection scores (MGPPSs). Cumulatively, haplotype-based MGPRSs and MGPPSs contributed to 9.6, 8.5 and 15.2% of the variance in general delinquency in adolescence, property/violent crimes in early adulthood and physical partner violence in early adulthood, respectively.

CONCLUSIONS

This study extends previous research by showing a cumulative effect of multiple haplotypes conferring risk and protection to antisocial behaviours in adolescence and early adulthood. The findings further support the relevance of concomitantly considering multiple serotonergic polymorphisms to better understand the genetic aetiology of antisocial behaviours. Future studies should investigate the interplay between risk and protective haplotype-based multilocus genetic profile scores with the environment.

DECLARATION OF INTEREST

I.O.-M. holds a Canada Research Chair in the developmental origins of vulnerability and resilience.

Maternal depressive symptoms and early childhood cognitive development: a review of putative environmental mediators

Despite the abundance of research investigating the associations between maternal depressive symptoms (MDS) and children's cognitive development, little is known about the putative mechanisms through which depressive symptoms are associated with children's cognitive development. The aim of this review was to summarize the literature on family mediators (i.e., maternal parenting behaviors, mother-child interactions, and family stress) involved in this association in early childhood. The review includes seven studies, five longitudinal and two cross-sectional, which tested putative mediators of the association between MDS and children's cognitive development. Studies were selected from online databases (PubMed, PsycNet) and manual searches. Only studies which quantitatively assessed associations between MDS in the postnatal period and child cognitive development in early childhood (i.e., 0-5 years) and included mediator variables were included in the review. Six out of seven studies identified mediating variables. The mediators included maternal responsiveness, parenting style, family dysfunction, the quality of the home environment, and maternal caregiving practices. Different mediators were identified across the reviewed studies. Maternal depressive symptoms are partly associated with child cognitive development via family processes and parenting practices. Various mediating processes are at play. Further research is needed on the role of maternal and paternal mental health and gene-environment correlations in this association. A better understanding of the mediating pathways is needed for the design of preventative intervention targeting specific family processes.

Multi-rater developmental trajectories of hyperactivity-impulsivity and inattention symptoms from 1.5 to 17 years: a population-based birth cohort study

The developmental course of hyperactivity-impulsivity and inattention symptoms from infancy to adolescence has not been documented in a population sample. The aim of this study was to describe the developmental course of hyperactivity-impulsivity and inattention symptoms from 1.5 to 17 years using multiple informants, and to identify perinatal risk factors associated with following elevated (high-risk) trajectories. Using a population-based birth cohort (n = 1374), symptom ratings from mothers (1.5-8 years), teachers (6-13 years) and participant self-reports (10-17 years) were combined using group-based multi-trajectory modeling to identify informants' convergence in identifying high-symptom trajectories of hyperactivity-impulsivity and inattention over time. Perinatal risk factors associated with high-symptom trajectories were identified using stepwise logistic regression. The study found that symptoms of hyperactivity-impulsivity broadly declined from 1.5 to 17 years while symptoms of inattention remained constant. 21.4% of participants followed elevated trajectories of hyperactivity-impulsivity and 20.2% followed elevated trajectories of inattention; 11.6% followed elevated trajectories of both types of symptoms concurrently. Risk factors for high-risk trajectories of hyperactivity-impulsivity were low maternal education, prenatal alcohol exposure, non-intact family, maternal depression, and low child IQ; for high-risk inattention they were prenatal street drug exposure, early motherhood, low maternal education, maternal depression and low child IQ. Risk factors for trajectories of high-risk hyperactivity-impulsivity and inattention concurrently were low maternal education, maternal depression, and low child IQ. The combination of longitudinal assessments from multiple informants (i.e., mother, teacher, participant-reports) provides a new way to characterize hyperactivity-impulsivity and inattention phenotypes over time.

Pathways of Association Between Childhood Irritability and Adolescent Suicidality

OBJECTIVE

Childhood irritability predicts suicidal ideation/attempt (suicidality), but it is unclear whether irritability is an independent and direct risk factor for suicidality or a marker of intermediate mental health symptoms associated with suicidality. This study aimed to identify developmental patterns of childhood irritability and to test whether childhood irritability is directly associated with suicidality or indirectly associated with intermediate mental health symptoms.

METHOD

One thousand three hundred ninety-three participants from the Québec Longitudinal Study of Child Development were followed from birth to 17 years. Teachers assessed irritability yearly (at 6-12 years) and children self-reported intermediate mental health symptoms (depression, anxiety, disruptiveness, and hyperactivity-impulsivity; at 13 years) and suicidality (at 15 and 17 years).

RESULTS

Four irritability trajectories were identified: low (74.7%), rising (13.0%), declining (7.4%), and persistent (5.0%). Children following a rising irritability trajectory (versus a low trajectory) were at higher suicidality risk. A large proportion of this association was direct (odds ratio 2.11, 95% CI 1.30-3.43) and a small proportion was indirect by depressive symptoms (accounting for 23% of the association; odds ratio 1.17, 95% CI 1.03-1.34). Children on a persistent irritability trajectory (versus a low trajectory) were at higher risk of suicidality and this association was uniquely indirect by depressive symptoms (accounting for 73% of the association; odds ratio 1.51, 95% CI 1.16-1.97). The declining trajectory was not related to suicidality; no association with anxiety, disruptiveness, and hyperactivity-impulsivity was found.

CONCLUSION

Rising irritability across childhood represents a direct risk for suicidality. Persistent irritability appears to be a distal marker of suicidality acting through more proximal depressive symptoms.

Childhood trajectories of peer victimization and prediction of mental health outcomes in midadolescence: a longitudinal population-based study

BACKGROUND

Exposure to peer victimization is relatively common. However, little is known about its developmental course and its effect on impairment associated with mental illnesses. We aimed to identify groups of children following differential trajectories of peer victimization from ages 6 to 13 years and to examine predictive associations of these trajectories with mental health in adolescence.

METHODS

Participants were members of the Quebec Longitudinal Study of Child Development, a prospective cohort of 2120 children born in 1997/98 who were followed until age 15 years. We included 1363 participants with self-reported victimization from ages 6 to 13 years and data available on their mental health status at 15 years.

RESULTS

We identified 3 trajectories of peer victimization. The 2 prevailing groups were participants with little or moderate exposure to victimization (441/1685 [26.2%] and 1000/1685 [59.3%], respectively); the third group (244 [14.5%]) had been chronically exposed to the most severe and long-lasting levels of victimization. The most severely victimized individuals had greater odds of reporting debilitating depressive or dysthymic symptoms (odds ratio [OR] 2.56, 95% confidence interval [CI] 1.27-5.17), debilitating generalized anxiety problems (OR 3.27, CI 1.64-6.51) and suicidality (OR 3.46, CI 1.53-7.81) at 15 years than those exposed to the lowest levels of victimization, after adjustment for sex, childhood mental health, family hardship and victimization perpetration. The association with suicidality remained significant after controlling for concurrent symptoms of depression or dysthymia and generalized anxiety problems.

INTERPRETATION

Adolescents who were most severely victimized by peers had an increased risk of experiencing severe symptoms consistent with mental health problems. Given that peer victimization trajectories are established early on, interventions to reduce the risk of being victimized should start before enrolment in the formal school system.

Risk Factors Associated With Boys' and Girls' Developmental Trajectories of Physical Aggression From Early Childhood Through Early Adolescence

Importance

This study used multitrajectory modeling to identify distinct trajectories of physical aggression from ages 1.5 to 13 years for boys and girls.

Objectives

To trace the development of boys' and girls' physical aggression problems from infancy to adolescence using mother ratings, teacher ratings, and self-ratings and to identify early family predictors of children on the high physical aggression trajectories.

Design, Setting, and Participants

This cohort study used data from the Quebec Longitudinal Study of Child Development (QLSCD), a study of a representative, population-based sample of 2223 infants born in 1997 and 1998 in the Canadian province of Quebec. The dates of analysis were January 2017 to January 2018.

Main Outcomes and Measures

Trained research assistants conducted 7 interviews (at child ages 1.5, 2.5, 3.5, 4.5, 5, 6, and 8 years) with the person most knowledgeable about the child (mothers in 99.6% [2214 of 2223] of cases). Teachers assessed the child's behavior at ages 6, 7, 8, 10, 12, and 13 years. Self-reports of behavior problems were obtained from the child at ages 10, 12, and 13 years.

Results

The sample included 2223 participants, 51.2% of whom were boys and 91.2% of whom were of white race/ethnicity. The mean response rate for mother ratings of physical aggression during the first 8 years of life was 80.9% (range, 65.1%-91.7%). For teacher ratings of physical aggression from ages 6 to 13 years, the mean response rate was 45.7% (range, 35.4%-56.9%), while the mean response rate of physical aggression assessment from self-ratings between ages 10 and 13 years was 57.9% (range, 55.2%-60.5%). Attrition was higher among families with low socioeconomic status and single-parent families, as well as among young mothers and mothers who were not fluent in French or English. A statistical analysis to examine the consequences of attrition was included. For boys and girls, the frequency of physical aggressions increased from age 1.5 years (2039 [91.7%]) to age 3.5 years (1941 [87.3%]) and then substantially decreased until age 13 years (1228 [55.2%]). Three distinct developmental trajectories of physical aggression were observed for girls and 5 for boys. Most family characteristics measured at 5 months after the child's birth were associated with a high physical aggression trajectory for boys and girls.

Conclusions and Relevance

Family characteristics at 5 months after the child's birth could be used to target preschool interventions aimed at preventing the development of boys' and girls' chronic physical aggression problems.