The relationship between genetic and environmental influences on resilience and on common internalizing and externalizing psychiatric disorders.

PURPOSE: Resilience to stressful life events (SLEs), which increase risk of psychopathology, is influenced by genetic factors. The purpose of this paper was to map the overlap of etiologic risk factors for resilience onto the broad psychopathological map. Resilience was defined as the difference between the twins' total score on a broad measure of internalizing symptoms and their predicted score based on their cumulative exposure to SLEs.

METHODS

Cholesky decompositions were performed with OpenMx to quantify the overlap in genetic and environmental risk factors between resilience and four phenotypes [major depression (MD), generalized anxiety disorder (GAD), alcohol abuse or dependence (AAD), and antisocial personality disorder (ASPD)].

RESULTS

The genetic factors that influence resilience account for 42 and 61 % of the heritability of MD and GAD, respectively, and 20 and 18 % for AAD and ASPD, respectively. The latent genetic contribution to MD was shared 47 % with resilience, and for AAD, this estimate was lower (23 %). The shared environmental covariance was nominal.

CONCLUSIONS

Genetic influences on resilience contribute to internalizing phenotypes to a higher degree than to externalizing phenotypes. Environmental influences can also have an enduring effect on resilience. However, virtually all of the covariance between resilience and the phenotypes was genetic.