A genetically informed study of the covariation between the CBCL/6-18 DSM-oriented problem scales and the competence scales.

In 398 twin pairs belonging to the population-based Italian Registry, we investigated by the monozygotic twin intrapair differences model and bivariate designs whether the phenotypic correlations between CBCL/6-18 problem behaviours and competencies could better be accounted for by direct, causal effects, or by the presence of latent etiological factors, acting simultaneously as elements of risk/protection for psychopathology and competencies. All zero-order correlations between six CBCL DSM-oriented scales (DOS) and three competence scales (CS) were negative and small-to-moderate. After implementing multiple regressions we found robust enough prediction only for ADH DOS on school CS, and for anxiety DOS on social CS. Results from the intrapair differences model indicated shared elements of liability, rather than direct causation, as more likely explanations for the negative phenotypic correlations between these emotional/behavioural problem and competencies scores. Bivariate analyses indicated shared genetic factors that influence simultaneously the emotional/behavioural problems and the competencies domains as the best explanations for the phenotypic covariations between DOS and CS.