OBJECTIVE:
Cocaine dependence is characterized by stress system
dysregulation, including elevated
cortisol activity,
emotional negativity, and behavioral disinhibition. High levels of stress and
glucocorticoids are also known to affect learning,
memory and
executive function. Therefore, we examined the relationships between chronic
cocaine use, elevated distress and learning and
memory dysfunction in
abstinent cocaine dependent (CD) individuals, and whether these measures were associated with
cocaine relapse outcomes. METHOD: Stress was assessed in 36 inpatient treatment engaged CD individuals and 36 demographically matched healthy control (HC) participants using the
Perceived Stress Scale (PSS) and repeated morning
salivary cortisol levels over three consecutive days. The Rey Auditory Verbal Learning Test (RAVLT) was conducted to measure verbal learning,
memory, and
executive function. Prospective assessment of
cocaine use outcomes during 90 days following discharge from inpatient treatment was also conducted. RESULTS: CD patients showed higher levels of distress compared to controls in PSS scores and
cortisol levels. They also demonstrated a significantly reduced learning curve, and fewer correct responses and more errors on recognition. Elevated
cortisol was significantly associated with worse RAVLT performance in CD patients. Poor
memory scores, but not distress measures, were significantly associated with greater
cocaine use after inpatient treatment. CONCLUSIONS: These findings are the first to demonstrate that learning and
memory deficits in CD individuals are associated with enhanced
cortisol and with
cocaine use outcomes after inpatient treatment. The findings are consistent with recent addiction models suggesting that chronic cocaine-related neuroadaptations affects learning and
memory function, which in turn, influences
drug use outcomes.
