Alcohol use and hippocampal volume deficits in adults with posttraumatic stress disorder: A meta-analysis.

Posttraumatic stress disorder (PTSD) is associated with hippocampal volume deficits, but the effects of alcohol use on hippocampal volume in PTSD are unclear. We meta-analytically examined the relationship between alcohol use, PTSD, and hippocampal volume deficits. Studies were initially searched through electronic databases. Twelve studies reporting data for the right hippocampal volume and 11 studies with data for the left hippocampal volume met initial inclusion criteria. In the meta-analysis of the studies in which subjects had no lifetime history of alcoholism, both the left and right hippocampal volumes were smaller in PTSD subjects compared to controls. Meta-regression using a continuous trial-level covariate showed that a lifetime history of alcoholism further moderates left and right hippocampal volume in PTSD. PTSD is associated with hippocampal volume deficits independent of a lifetime history of alcoholism, but alcoholism further contributes to the hippocampal volume deficits associated with PTSD.