Neuropsychological deficits and opiate abuse.

Cognitive functioning was examined in people with a current or past history of opiate abuse using a range of neuropsychological tests. Sixty percent of those currently abusing opiates showed impairments of at least two standard deviations from the published norms on two or more neuropsychological tests, a significantly higher incidence than found in matched controls with no history of drug abuse. The drug free group of recovering addicts fell between the other groups without significant differences. It was concluded that the risk of neuropsychological impairment is greater in opiate abusers, and that recovery may occur during abstinence.