Effects of acute cortisol and cocaine administration on attention, recall and recognition task performance in individuals with cocaine dependence.

This study investigated the effects of acute cocaine administration on cognition, and whether these can be modeled using exogenous hydrocortisone, because cocaine-induced cortisol elevations may influence its cognitive effects. Twelve cocaine-dependent individuals received an intravenous bolus of cortisol (0.5 or 0.2 mg/kg) and cocaine (0.2 mg/kg) in a double-blind randomized placebo-controlled and counterbalanced fashion. Cognitive testing included verbal tasks of vigilance attention, free recall and recognition memory before the boluses and at 20, 60 and 100 min thereafter. The statistical analysis investigated dose response effects while accounting for all sources of variance in the design. No effects of low dose cocaine were found on any variables. Low dose cortisol enhanced and high dose impaired vigilance attention, and a trend was found for the same dose response profile on twice-heard words. An opposite trend, inconsistent with prior research on cortisol and cognition, was observed for recognition: low dose impaired and high dose enhanced recognition of once-heard words, and a very weak trend was found for recognition of new words. These findings, though tempered by design limitations, suggest a complex non-linear cortisol attention/recognition dose-response relationship and call for further research to elucidate cortisol's effects on cognition and their role in the pathophysiology of cocaine dependence.