This research project aims to identify factors that contribute to the heterogeneity observed in neuroradiological and neuropsychological signs of chronic alcoholism. The investigators overarching hypothesis is that the heterogeneity of alcoholic consequences on brain structure and metabolism, and cognition is mainly related to individual differences in pattern of alcohol use, gene pool, nutritional status and history of withdrawal symptoms.

Inclusion Criteria:

• Completed at least 8 years of education (primary school equivalent)
• Age-normal corrected hearing and visual acuity

Exclusion Criteria:

• documented loss of consciousness of over 30 minutes, documented compound skull fracture, or clear neurological sequelae of head trauma
• history of medical or neurological illness or trauma potentially affecting the CNS, e.g., stroke, multiple sclerosis, epilepsy, psychosurgery, insulin coma.
• active tuberculosis or history of or any malignancy requiring chemotherapy
• history of schizophrenia or bipolar disorder
• metal implantation (e.g., pacemakers) or other factors that preclude MRI scanning for subjects selected for the neuroimaging examination
• meet DSM-IV criteria for current (past 3 months) other Substance Abuse
• met DSM-IV criteria for other Substance Dependence
• Have used other substances more than 5 times in the past month