Cognitive impairment in acute cocaine withdrawal

Objective: To perform a pilot study to examine a range of cognitive flexibility tasks early in cocaine withdrawal. Background: Previous neuropsychological investigations of cocaine withdrawal have conflicted regarding whether impaired cognitive flexibility occurs. However, most studies have examined patients later in withdrawal. Anxiety and yohimbine-induced panic are greatest early in withdrawal, and both anxiety and increased noradrenergic tone can impair cognitive flexibility. Method: Twelve patients acutely withdrawing from cocaine were compared with gender-, age-, and estimated premorbid intelligence-matched control subjects on tests of cognitive flexibility as well as verbal fluency, verbal memory, spatial memory, and attention. Results: As predicted, impairments were found on the cognitive flexibility tasks. Impairments also were present in verbal fluency and verbal memory but not spatial memory or attention. Conclusions: We propose that the cognitive flexibility impairment may relate to the increased noradrenergic activation recently described in cocaine withdrawal. Impairments on verbal tasks may also relate to an impaired flexibility in the search of semantic networks. Further research will explore the effects of pharmacologic manipulation of the noradrenergic system on cognition in acute withdrawal. Recently, propranolol has been shown to benefit patients in cocaine withdrawal. Further research will explore whether impaired cognitive flexibility related to altered noradrenergic tone could serve as a mechanism for this treatment response.