A pilot study of neurocognitive function in older and younger cocaine abusers and controls

This pilot study compared basic neurocognitive functioning among older and younger cocaine abusers and control participants, as a preliminary assessment of whether specific cognitive deficits exist in an aged cocaine-abusing population. We hypothesized an interaction between aging and cocaine abuse, such that older cocaine abusers would exhibit decreased neuropsychological test performance relative to both younger cocaine abusers and older control participants. Four groups (n = 20 each) were examined: older cocaine abusers (ages 51-70), younger cocaine abusers (ages 21-39), and two non-illicit substance-using control groups. Basic neuropsychological and psychiatric measures were administered to all participants. Older participants performed more poorly than younger participants on the Mini-Mental State Examination (MMSE, p < .01), Digit Span Backward (p < .01), and Trail Making Test (TMT) Parts A and B (p < .01). Cocaine abusers performed more poorly than controls on TMT A (p < .01). Older and younger cocaine abusers used similar amounts of cocaine (p > .05). Older cocaine abusers performed more poorly than older control participants and younger cocaine abusers on the Digit Span Forward (p < .0125). Older cocaine abusers also performed more poorly than younger cocaine abusers on TMT A (p < .0125). This study provides preliminary evidence that older cocaine abusers use a significant amount of cocaine and that there is an interaction between aging and cocaine abuse on psychomotor speed, attention, and short-term memory. Future examination of neurocognitive function in older cocaine abusers is clearly warranted.