EVENT-RELATED POTENTIAL EVIDENCE FOR FRONTAL-CORTEX EFFECTS OF CHRONIC COCAINE DEPENDENCE

We examined the effects of cocaine dependence and cocaine and alcohol codependence on the P3A event-related potential component. Ten chronic cocaine-dependent subjects, 10 chronic cocaine and alcohol codependen t subjects, and 20 controls were studied in an auditory paradigm that included target, nontarget, and novel rare nontarget conditions. Subst ance dependent subjects were abstinent from cocaine and/or alcohol for 2-6 weeks. Eighteen of these subjects (4 chronic cocaine-dependent su bjects, 4 chronic cocaine/alcohol codependent subjects, and 10 normal controls) were also studied in an analogous visual paradigm. In the au ditory modality, the latency of the P3A response in the novel rare non target condition was delayed and its amplitude was reduced in both sub stance-dependent samples compared to controls. Comparable results were found for the smaller samples studied in the visual modality. These r esults suggest that chronic cocaine dependence produces deficits in fr ontal cortex functions. (C) 1997 Society of Biological Psychiatry.