The role of alcohol in cocaine dependence.

The relationships between the patterns of alcohol and cocaine use are examined using information derived from the authors' research data and from the literature. Excessive alcohol drinking was very prevalent among males seeking treatment for cocaine dependence at a Veterans Administration hospital in West Los Angeles. Fifty percent met DSM-III-R criteria for alcohol dependence. The drug-related behaviors of patients with the diagnosis of dependence on cocaine only were compared with those of patients dependent on cocaine and alcohol. The progression of the cocaine addiction was not significantly different in those two groups. However, patients with dependence on cocaine and alcohol were more likely to be users of other drugs of abuse. Concerning psychosocial behaviors, both groups maintained employment and stable interpersonal relationships throughout significant periods of their addictive career. One year after drug treatment, both subsamples showed significant improvement in terms of cocaine and alcohol use and social adjustment. Research implications and the possibility that both dependent conditions may share neurobehavioral reinforcing mechanisms are discussed.