Stress and development of depression and heavy drinking in adulthood: moderating effects of childhood trauma.

PURPOSE: Studies suggest that childhood trauma is linked to both depression and heavy drinking in adulthood, and may create a lifelong vulnerability to stress. Few studies have explored the effects of stress sensitization on the development of depression or heavy drinking among those who have experienced traumatic childhood events. This study aimed to determine the effect of childhood trauma on the odds of experiencing depression or heavy drinking in the face of an adult life stressor, using a large population-based Canadian cohort.
METHODS: A total of 3,930 participants were included from the National Population Health Survey. The associations among childhood trauma, recent stress and depression/heavy drinking from 1994/1995 to 2008/2009 were explored using logistic regression, as were interactions between childhood trauma and recent stress. A generalized linear mixed model was used to determine the effects of childhood trauma and stressful events on depression/heavy drinking. Analyses were stratified by sex.
RESULTS: Childhood trauma significantly increased the odds of becoming depressed (following 1 event: OR = 1.66; 95%CI 1.01, 2.71; 2+ events, OR = 3.89; 95%CI 2.44, 6.22) and drinking heavily (2+ events: OR = 1.79; 95%CI 1.03, 3.13). Recent stressful events were associated with depression, but not heavy drinking. While most interaction terms were not significant, in 2004/2005 the association between recent stress and depression was stronger in those who reported childhood trauma compared to those with no childhood trauma.
CONCLUSIONS: Childhood trauma increases risk for both depression and heavy drinking. Trauma may moderate the effect of stress on depression; the relationship among trauma, stress and heavy drinking is less clear.