GENETIC CONTRIBUTIONS TO CONTINUITY, CHANGE, AND COOCCURRENCE OF ANTISOCIAL AND DEPRESSIVE SYMPTOMS IN ADOLESCENCE

In adolescence, antisocial and depressive symptoms are moderately stab le and modestly correlated with each other. We examined the genetic an d environmental origins of the stability and change of antisocial and depressive symptoms and their co-occurrence cross-sectionally and long itudinally in a national sample of 405 adolescents. Monozygotic (MZ) a nd dizygotic (DZ) twins and full, half, and unrelated siblings 10-18 y ears of age from nondivorced and stepfamilies were studied over a 3-ye ar period. Composite measures of adolescent self-reports, parent repor ts, and observational measures of antisocial and depressive symptoms w ere analysed in multivariate behavioural genetic models. Results indic ated that the majority of the stability in and co-occurrence between d imensions could be accounted for by genetic factors. Nonshared environ mental risks and, for antisocial symptoms, shared environmental risks also contributed to the stability. Genetic influences on change were o bserved, but only for antisocial behaviour. In addition, the longitudi nal association between antisocial behavioural and later depressive sy mptoms was also found to be genetically mediated, but this effect was nonsignificant after controlling for stability. Results are discussed in light of the potential contributions of developmental behavioural g enetic research in understanding individual differences in the stabili ty and change of maladjustment.