The impact of adverse life events on clinical features and interaction with gene variants in mood disorder patients

Background: Adverse life events are precipitating and maintenance factors for mood and anxiety disorders. However, the impact of such events on clinical features and treatment response is still unclear. Sampling and Methods: The aim of this study was to investigate whether specific adverse events (early parental loss and physical abuse) influence clinical features in a sample of 1,336 mood disorder patients, and whether genetic parameters interact with adverse events to influence treatment outcomes in a subsample of 252 subjects. Participants were collected in the context of a European multicenter study and treated with antidepressants at adequate doses for at least 4 weeks. We focused on two genes (BDNF and CREB1) due to prior evidence of association with treatment outcomes in the same sample. Results: Patients with a history of physical abuse had higher suicidal risk (including history of attempts), comorbid panic disorder, posttraumatic stress disorder and alcohol dependence compared to non-abused patients. Experience of early parental loss was a less detrimental type of life stressor. Treatment response was not affected by adverse events. No gene-environment interaction was found with genetic variations, using a corrected significance level. Conclusions: A limitation of the present study is that the subsample is too small for detecting gene-environment interactions. The clinical message of our findings is that mood disorder patients with a history of physical abuse showed a worse clinical profile, characterized by higher comorbid Axis I psychopathology and increased suicidal behavior.