Effect of the serotonin transporter gene and of environment on the continuity of anxiety and depression traits throughout adolescence.

Aims. Many studies of various stress reactive phenotypes suggest that 5-HTTLPR short allele carriers (S-carriers) are characterised by the stable trait of negative affectivity that is converted to psychopathology only under conditions of stress. In this study, we examined the moderating role of the 5-HTTLPR on the relationship between two objective chronic risk factors, i.e. socioeconomic status (SES) and family structure, and internalising symptoms across adolescence. Methods. A multigroup path analysis was employed in a general adolescent population sample of a 5-year follow-up study. Results. Internalising problems were significantly more stable in the S-carriers. The focus on the main dimensions of internalising problems, i.e. anxiety and depression, revealed two different developmental patterns. In the S-carriers Anxiety problems seemed to be more stable and to predict a possible evolution towards the development of Depressive problems. In the long allele homozygotes (LL-subjects) the anxiety trait was significantly less stable, and, in late-adolescence, seemed to be significantly predicted by SES, suggesting a possible gene-environment interaction (G × E). Family structure seemed to play a role in a G × E perspective only until early-adolescence, while during late-adolescence SES seemed to play a pivotal role in interaction with 5-HTTLPR, with the S-allele playing a protective role. Conclusions. Future models of the developmental link between environmental adversities and internalising behaviour therefore need to consider that the effect of G × E interaction, may be associated with internalising behaviour via different mechanisms during different time frames and that shifts in the strength of this effect should be expected across development.

Psychopathology and adversities from early- to late-adolescence: a general population follow-up study with the CBCL DSM-Oriented Scales.

Aims. Adolescence is a critical transition phase between childhood and adulthood, when the burden of mental disorder may still be prevented. The aim of this study was to evaluate the continuity and discontinuity of behavioural problems in adolescence while taking into account the multiple co-variation of psychopathological traits and the complex role of recent stressful life events (SLEs). Methods. This is a 5-year follow-up investigation of emotional and behavioural problems assessed by the newly developed Child Behavior Checklist (CBCL) DSM-Oriented Scales (DOSs) in 420 general population subjects aged 15-19 years. Results. The DOSs showed good stability, even when multiple co-variation was taken into account. Longitudinal data showed that homotypic evolution of psychopathology was to be expected in the first place. Equifinality and multifinality were also found. Oppositional Defiant Problems emerged to be polyvalent predictors of both internalizing and externalizing problems. Furthermore, Oppositional Defiant Problems predicted more SLEs, which in turn predicted more Depression, Anxiety and Oppositional Defiant Problems. Mediational analyses confirmed the role of SLEs in partially accounting for the continuity of Oppositional Defiant Problems and for the heterotypic progression towards Affective Problems. Conclusions. These data underscore early adolescence behavioural problems as an important focus for primary and secondary intervention.