Declarative and procedural memory functioning in abstinent cocaine abusers

Background: We determined the nature and recovery of procedural and declara tive memory functioning in a cocaine-abusing cohort in the 45-day period fo llowing use. Methods: Thirty-seven cocaine abusers and 27 control subjects were administ ered the following memory and mood measures: California Verbal Learning Tes t, recall of the Rey-Osterrieth Complex Figure Test, Pursuit Rotor Task, an d Profile of Mood States at 4 visits (within 72 hours of admission and at 1 0, 21, and 45 days following abstinence). Results: Analysis of performance on the Rey-Osterrieth Complex Figure Test revealed that both groups improved in their recall over repeated administra tions, though the control group recalled significantly more of the informat ion than cocaine subjects during the 45-day interval. Results for the Calif ornia Verbal Learning Test indicated improved learning for both subject gro ups over time, but no group x time interaction. On the Pursuit Rotor Task, cocaine abusers improved their performance at a faster rate than controls a t visit 1. At day 45 (visit 4), cocaine abusers again showed improvement on the Pursuit Rotor Task, whereas controls demonstrated a relative plateau i n rate of learning. Conclusions: This study documented a lasting detrimental effect on a sensit ive nonverbal declarative memory task in cocaine-dependent subjects followi ng abstinence of 45 days. In contrast, abstinence from cocaine during this 45-day period was associated with sustained improvement on a motor learning test in the cocaine abusers relative to controls.