Using a genetically informed twin design, this study examined (a) whether, in line with gene-environment correlation (rGE), a genetic disposition for anxiety puts children at risk of being victimized ...by a close friend or by other peers, and (b) whether, in line with gene-environment interaction (GxE), victimization by a close friend or by other peers moderates the expression of a genetic disposition for anxiety. Participants were 268 monozygotic and dizygotic twin pairs (MZ males = 71, MZ females = 80, DZ males = 56, DZ females = 61; 87% of European descent) assessed via questionnaires in Grade 8 (M age = 14.06 years, SD = 3.60). Participants reported about their victimization by a close friend and by other peers and their anxiety level. Victimization by a close friend and victimization by other peers were uncorrelated. In line with rGE, genetic factors related to anxiety predicted victimization by other peers, whereas victimization by a close friend was not predicted by heritable characteristics. Moreover, in line with a suppression process of GxE, victimization by other peers reduced the role of genetic factors in explaining interindividual differences in anxiety. In contrast, in line with a diathesis-stress process of GxE, victimization by a close friend fostered the expression of a genetic disposition for anxiety. Victimization by a close friend seems to happen to adolescents regardless of their personal, heritable characteristics. If it does occur, however, it is a source of distress mostly for youth with a genetic vulnerability for anxiety.
Few studies are grounded in a developmental framework to study proactive and reactive aggression. Furthermore, although distinctive correlates, predictors and outcomes have been highlighted, ...proactive and reactive aggression are substantially correlated. To our knowledge, no empirical study has examined the communality of genetic and environmental underpinning of the development of both subtypes of aggression. The current study investigated the communality and specificity of genetic-environmental factors related to heterogeneity in proactive and reactive aggression's development throughout childhood.
Participants were 223 monozygotic and 332 dizygotic pairs. Teacher reports of aggression were obtained at 6, 7, 9, 10 and 12 years of age. Joint development of both phenotypes were analyzed through a multivariate latent growth curve model. Set point, differentiation, and genetic maturation/environmental modulation hypotheses were tested using a biometric decomposition of intercepts and slopes.
Common genetic factors accounted for 64% of the total variation of proactive and reactive aggression's intercepts. Two other sets of uncorrelated genetic factors accounted for reactive aggression's intercept (17%) on the one hand, and for proactive (43%) and reactive (13%) aggression's slopes on the other. Common shared environmental factors were associated with proactive aggression's intercept (21%) and slope (26%) and uncorrelated shared environmental factors were also associated with reactive aggression's slope (14%). Common nonshared environmental factors explained most of the remaining variability of proactive and reactive aggression slopes.
A genetic differentiation hypothesis common to both phenotypes was supported by common genetic factors associated with the developmental heterogeneity of proactive and reactive aggression in childhood. A genetic maturation hypothesis common to both phenotypes, albeit stronger for proactive aggression, was supported by common genetic factors associated with proactive and reactive aggression slopes. A shared environment set point hypothesis for proactive aggression was supported by shared environmental factors associated with proactive aggression baseline and slope. Although there are many common features to proactive and reactive aggression, the current research underscores the advantages of differentiating them when studying aggression.
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.
Both common pain and anxiety problems are widespread, debilitating and often begin in childhood-adolescence. Twin studies indicate that this co-occurrence is likely due to shared elements of risk, ...rather than reciprocal causation. A joint genome-wide investigation and pathway/network-based analysis of adolescent anxiety and pain problems can identify genetic pathways that subserve shared etiopathogenetic mechanisms. Pathway-based analyses were performed in the independent samples of: The Quebec Newborn Twin Study (QNTS; 246 twin pairs and 321 parents), the Longitudinal Study of Child Development in Quebec (QLSCD; n = 754), and in the combined QNTS and QLSCD sample. Multiple suggestive associations (p<1×10-5), and several enriched pathways were found after FDR correction for both phenotypes in the QNTS; many nominally-significant enriched pathways overlapped between pain problems and anxiety symptoms (uncorrected p<0.05) and yielded results consistent with previous studies of pain or anxiety. The QLSCD and the combined QNTS and QLSCD sample yielded similar findings. We replicated an association between the pathway involved in the regulation of myotube differentiation (GO:0010830) and both pain and anxiety problems in the QLSDC and the combined QNTS and QLSCD sample. Although limited by sample size and thus power, these data provide an initial support to conjoint molecular investigations of adolescent pain and anxiety problems. Understanding the etiology underlying pain and anxiety co-occurrence in this age range is relevant to address the nature of comorbidity and its developmental pathways, and shape intervention. The replication across samples implies that these effects are reliable and possess external validity.
Background: Reactive and proactive subtypes of aggressive 10–11–12‐year‐old children were compared with non‐aggressive children to examine whether the two forms of aggression were differentially ...related to antecedent and subsequent measures. Method: A large community sample of boys and girls was used. Reactive and proactive aggression was measured through teacher ratings when the children were 10, 11 and 12 years old. Antecedent measures were age 6 temperament and behavioral dispositions; subsequent measures were age 13 delinquency and depressive symptoms. Results: Results indicated that reactive and proactive children had distinctive profiles on antecedent and subsequent measures. Conclusions: We conclude that children characterized by reactive or proactive aggression differ on several dimensions of personal functioning, and that reactive and proactive aggression are distinct forms of aggression, although both co‐occur in a large proportion of aggressive children.
Abstract Purpose Recent years have seen increased coverage of adolescent victimization and suicide. Both adolescent peer victimization and substance use have been associated with suicidal ideation, ...with evidence suggesting that all three factors are interrelated. There are at least four models which can explain the associations between these factors (i.e., self-medication, secondary mental disorder, bidirectional, and common factor). However, none of them is being empirically supported as the dominant model because few longitudinal studies have explored the association between these factors. Methods The present study compared longitudinal paths of all four models simultaneously using a cross-lagged model. This was done using self-reported measures of peer victimization, suicidal ideation, and alcohol use at age 13, 14, and 15 years in a longitudinal sample of 238 adolescents. Results All three variables were moderately stable across time. Significant cross-lagged associations were found, showing that frequent peer victimization at age 13 years was associated with higher odds of having suicidal ideation at age 14 years (odds ratio, 1.82; p < .05). In turn, presence of suicidal ideation at age 14 years was significantly associated with higher alcohol use frequency at age 15 years (β = .13; p < .05). Conclusions Results support previous literature suggesting that peer victimization predates alcohol use and extends it by showing clear directionality between suicidal ideation and alcohol use over 1 year, supporting the self-medication model. Clarifying the empirical basis of these underlying models could allow for earlier prevention strategies, by targeting the risk factor that appears the earliest in the model.
Animal and human studies suggest that inflammation is associated with behavioral disorders including aggression. We have recently shown that physical aggression of boys during childhood is strongly ...associated with reduced plasma levels of cytokines IL-1α, IL-4, IL-6, IL-8 and IL-10, later in early adulthood. This study tests the hypothesis that there is an association between differential DNA methylation regions in cytokine genes in T cells and monocytes DNA in adult subjects and a trajectory of physical aggression from childhood to adolescence.
We compared the methylation profiles of the entire genomic loci encompassing the IL-1α, IL-6, IL-4, IL-10 and IL-8 and three of their regulatory transcription factors (TF) NFkB1, NFAT5 and STAT6 genes in adult males on a chronic physical aggression trajectory (CPA) and males with the same background who followed a normal physical aggression trajectory (control group) from childhood to adolescence. We used the method of methylated DNA immunoprecipitation with comprehensive cytokine gene loci and TF loci microarray hybridization, statistical analysis and false discovery rate correction. We found differentially methylated regions to associate with CPA in both the cytokine loci as well as in their transcription factors loci analyzed. Some of these differentially methylated regions were located in known regulatory regions whereas others, to our knowledge, were previously unknown as regulatory areas. However, using the ENCODE database, we were able to identify key regulatory elements in many of these regions that indicate that they might be involved in the regulation of cytokine expression.
We provide here the first evidence for an association between differential DNA methylation in cytokines and their regulators in T cells and monocytes and male physical aggression.
We report on the psychometric properties of the Mental Health and Social Inadaptation Assessment for Adolescents (MIA), a self‐report instrument for quantifying the frequency of mental health and ...psychosocial adaptation problems using a dimensional approach and based on the DSM‐5. The instrument includes 113 questions, takes 20–25 minutes to answer, and covers the past 12 months. A population‐based cohort of adolescents (n = 1443, age = 15 years; 48% males) rated the frequency at which they experienced symptoms of Attention Deficit Hyperactivity Disorder (ADHD), Conduct Disorder, Oppositional Defiant Disorder, Depression, Generalized Anxiety, Social Phobia, Eating Disorders (i.e. DSM disorders), Self‐harm, Delinquency, Psychopathy as well as social adaptation problems (e.g. aggression). They also rated interference with functioning in four contexts (family, friends, school, daily life). Reliability analyses indicated good to excellent internal consistency for most scales (alpha = 0.70–0.97) except Psychopathy (alpha = 0.46). The hypothesized structure of the instrument showed acceptable fit according to confirmatory factor analysis (CFA) Chi‐square (4155) = 9776.2, p = 0.000; Chi‐square/DF = 2.35; root mean square error of approximation (RMSEA) = 0.031; Comparative Fit Index (CFI) = 0.864, and good convergent and discriminant validity according to multitrait‐multimethods analysis. This initial study showed adequate internal validity and reliability of the MIA. Our findings open the way for further studies investigating other validity aspects, which are necessary before recommending the wide use of the MIA in research and clinical settings.
The Quebec Newborn Twin Study (QNTS) is an ongoing prospective longitudinal follow-up of a birth cohort of twins born between 1995 and 1998 in the greater Montreal area, Québec, Canada. The goal of ...QNTS is to document individual differences in the cognitive, behavioral, and social-emotional aspects of developmental health across childhood, their early bio-social determinants, as well as their putative role in later social-emotional adjustment, school and health outcomes. A total of 662 families of twins were initially assessed when the twins were aged 6 months. These twins and their family were then followed regularly. QNTS has 14 waves of data collected or planned, including 5 in preschool. Over the past 15 years, a broad range of physiological, cognitive, behavioral, school, and health phenotypes were documented longitudinally through multi-informant and multi-method measurements. QNTS also entails extended and detailed multi-level assessments of proximal (e.g., parenting behaviors, peer relationships) and distal (e.g., family income) features of the child's environment. This detailed longitudinal information makes QNTS uniquely suited for the study of the role of the early years and gene-environment transactions in development.
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. Keywords: Eating disorder symptoms, Sex-specificity, Developmental trajectories, Adolescence, Mental health
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