The effects of nonshared environments on adolescent depression: findings from a sample of monozygotic twins

Investigating Unique Environmental Influences of Parenting Practices on Youth Anxiety

The associations between parenting practices and adolescent anxiety symptoms were examined in both individual and monozygotic (MZ) twin differences levels. Participants were 804 pairs of Chinese MZ adolescent twins aged 10–18 years ( M = 13.57, SD = 2.67, 52% females). Twins’ anxiety symptoms were assessed by self- and parent-reports. Twins also reported their perceived parenting practices. On the individual level, parental warmth-reasoning was negatively, whereas harshness-hostility was positively, associated with both self- and parent-reported youth anxiety. On the MZ-twin differences level, the magnitudes of the associations between parenting practices and youth anxiety were decreased. MZ-twin difference in parental warmth-reasoning remained significantly associated with self- and parent-reported youth anxiety; MZ-twin difference in parental harsh-hostility was only significantly associated with self-reported youth anxiety. This study indicated that parental warmth-reasoning and harshness-hostility may be unique environmental experiences that influence youth anxiety, and illustrated the necessity of controlling for gene-environment correlations when examining the true environmental effects of parenting on child behavior.

Social coping by masking? Parental support and peer victimization as mediators of the relationship between depressive symptoms and expressive suppression in adolescents

Expressive suppression is regarded as a generally ineffective emotion regulation strategy and appears to be associated with the development of depressive symptoms among adolescents. However, the mechanisms linking suppression to depressive symptoms are not well understood. The main aim of this study was to examine two potential mediators of the prospective relationship from depressive symptoms to expressive suppression among adolescents: parental support and peer victimization. Structural equation modelling was used to construct a three-wave cross-lagged model (n = 2,051 adolescents, 48.5 % female, at baseline; 1,465 with data at all three time points) with all possible longitudinal linkages. Depressive symptoms preceded decreases in perceived parental support 1 year later. Decreases in parental support mediated the relationship between depressive symptoms and increases in expressive suppression over a 2-year period. Multi-group analyses show that the mediation model tested was significant for girls, but not for boys. No evidence for other mediating models was found. Although initial suppression preceded increases in depressive symptoms 1 year later, we did not find any evidence for the reversed link from suppression to depressive symptoms. Clear evidence for a reciprocal relationship between depressive symptoms and parental support was found. However, only limited and inconsistent support was found for a reciprocal relationship between depressive symptoms and peer victimization. Finally, although some evidence for a unidirectional relationship from parental support to increases in suppression was found, no significant prospective relationship was found between peer victimization and suppression. The implications of our clear results for parental support, and mostly lacking results for peer victimization, are discussed.

Height in adolescence predicts polydrug use in adolescence and young adulthood

Prior research has noted a relationship between an individual's height in adolescence and their personality development later in life. This study examined whether height in adolescence--net of possible confounding variables such as age and biological maturity--predicted polydrug use in adolescence and young adulthood. The results revealed a positive and statistically significant association, wherein taller youths were more likely to report using an array of drugs. Supplemental analyses indicated that the relationship is not specific to males as some theories would suggest. Possible mediating mechanisms such as exposure to drug-using peers, self-control, depression, and self-esteem are considered. Implications of the findings are discussed.