SMALLER VOLUME OF PREFRONTAL LOBE IN POLYSUBSTANCE ABUSERS - A MAGNETIC-RESONANCE-IMAGING STUDY

The present study was conducted to test the hypothesis that individual s with substance abuse disorder exhibit structural deficits in the pre frontal cortex. Volumes of the prefrontal lobe in subjects with histor ies of polysubstance abuse (n = 25) were measured and compared with th ose in normal volunteers (n = 14), using high-resolution volumetric ma gnetic resonance imaging (MRI). The research participants were men, 22 to 41 years of age. Polysubstance abusers were abstinent from drugs o f abuse (except nicotine) for at least 15 days before MRI scanning. Th e total volumes of the prefrontal lobe (left and right hemispheres) we re significantly smaller in the substance abuse group than in the cont rol group. When the prefrontal lobe was segmented for gray and white m atter, the deficit in the substance abusers was seen as significantly smaller volumes of gray but not of white matter. These results indicat e that hypoplasia and/or atrophy in the prefrontal cortex accompany su bstance abuse and suggest that structural deficits in the prefrontal c ortex may play an essential role in the neuropathological basis of fun ctional impairments in substance abuse disorder, as demonstrated by fu nctional brain imaging and cognitive studies. Published by Elsevier Sc ience Inc.