CNS recovery from cocaine, cocaine and alcohol, or opioid dependence: a P300 study.

OBJECTIVES: The goal of the present study was to evaluate the relative effects of cocaine, cocaine and alcohol, or opioid dependence on P300 event-related potentials (ERPs). In addition, the effects of selected premorbid and comorbid factors were examined.
METHODS: P300 ERPs were recorded from 72 residential treatment program patients, characterized by a history of either cocaine (n=25), or cocaine and alcohol (n=18), or opioid (n=29) dependence, and 14 non-drug-dependent community volunteers. The 86 subjects completed a visual continuous performance test formed by a series of 150 presentations of individual consonant letters. They were asked to press a key whenever a letter was presented twice in succession.
RESULTS: Analyses of P300 ERPs obtained on target trials revealed a similar amplitude decrement in all the patient groups. Further analyses of P300 activity in the 3 drug-dependent patient groups revealed a negative correlation between P300 amplitude and the number of DSM-IIIR childhood conduct disorder criterion behaviors as well as a positive correlation between P300 amplitude and the duration of drug abstinence.
CONCLUSIONS: P300 amplitude in drug-dependent patients is influenced by a complex interaction between CNS pathology that predates, and probably promotes, the onset of drug dependence and CNS pathology that resolves during the process of recovery from drug dependence.