Relationships among aging, IQ, and intracranial volume in alcoholics and control subjects.

The current article examined the relationships among aging, intelligence, intracranial volume, and brain shrinkage in alcoholics and nonalcoholic controls. Magnetic resonance imaging was used to measure intracranial and cerebral volumes in 146 subjects with alcohol use disorders and 42 comparison subjects who were not alcoholic. The authors' findings show that performance on Block Design decreases as alcoholics age, and this decrease is predicted by brain shrinkage. This is consistent with a process of cumulative brain damage related to alcohol use. However, the authors' data also show that vocabulary does not decrease with age and is correlated with premorbid brain size as measured by intracranial volume, suggesting that lower verbal ability precedes heavy alcohol use and may be a risk factor for alcoholism.