Sex differences in neurocognitive functioning among abstinent recreational cocaine users

Rationale: There are clear sex differences in the onset and course of cocaine addiction, females being at greater risk. Neurocognitive impairments associated with cocaine use are also well documented. However, there are no studies of sex differences in neurocognitive performance among cocaine users. Objectives: The present study was designed to examine, for the first time, putative sex-related variations in cognition among recreational cocaine users. It was predicted that female users would perform poorer compared with male users based on the worse effects of cocaine abuse in women. Methods: A neuropsychological battery was administered to abstinent (72 h) recreational cocaine users (20 males and 20 females) and non-drug-using controls (19 males and 20 females) including tests of attention, executive functioning, verbal fluency (letter and category), verbal memory and visuospatial perception. Results: Male users demonstrated poorer attention compared with male controls, and greater verbal recognition errors than male controls and female users. Female users did not differ significantly in any other cognitive domain compared with male users or female controls. These results remained after controlling for dose-dependent variables. General dose-dependent effects were found for attention, visuospatial perception and components of verbal memory. Conclusions: Whilst these data partially support the notion of sex-related neurocognitive variation in short-term abstinence from recreational cocaine use, they do not suggest that sex is a major factor.