Increased early life stress and depressive symptoms in patients with comorbid substance abuse and schizophrenia

Early adverse events have been associated with increased rates of substance abuse and depression. To investigate the association between early adverse events and comorbid substance abuse in schizophrenia patients, early life stress, depressive symptoms, positive and negative symptoms, anxiety, and cognitive function were measured in an age-, sex-, and race-matched sample of 40 schizophrenia patients with and without comorbid substance abuse. Compared to patients without substance abuse, patients with schizophrenia and a history of substance abuse had a significantly higher incidence of early life trauma, as well as significantly higher scores on the Modified Hamilton Rating Scale for Depression and the Psychiatric Epidemiology Research Interview Life Events Scale. No differences between groups were found in positive or negative symptoms, anxiety, or cognitive function. The results emphasize the importance of early life stress and affective symptoms and their potential relationship to substance abuse disorders in schizophrenia patients.