Correlates of polysomnographic sleep changes in cocaine dependence: Self-administration and clinical outcomes

Background: Abstinence from chronic cocaine use is associated with abnormal sleep architecture. As sleep abnormalities are associated with clinical outcome in alcohol dependence, we hypothesized a similar relationship in cocaine dependence. Methods: We report data from a cocaine self-administration study (N =12) and the placebo arm of a randomized clinical trial (N=20). Self-administration participants underwent three cocaine self-administration sessions during a three-week inpatient stay. Treatment participants underwent two weeks of inpatient followed by six weeks of outpatient treatment including once-weekly cognitive behavioral therapy. Measurements included polysomnography from early and late in abstinence during the inpatient stays. Clinical outcomes included amount of cocaine self-administered, urine tests, and self-reported use and withdrawal symptoms. Results: Change in slow-wave sleep from early to late abstinence (Delta SWS; p = 0.05), late abstinence rapid eye movement sleep (REM; p = 0.002), and late abstinence total sleep time (p = 0.02) were negatively correlated with the amount of cocaine self-administered. Early abstinence REM was positively correlated with withdrawal symptoms (p = 0.02). Late abstinence REM was positively correlated with percent negative urines and maximum consecutive number of days abstinent (both p <0.001). Delta SWS was positively correlated with percent negative urines (p = 0.03) and participants with increased SWS had greater percent negative urines (p = 0.008) and maximum consecutive number of days abstinent (p = 0.009). Conclusions: Correlations between sleep deficits and amount of cocaine self-administered, clinical outcomes, and severity of withdrawal symptoms underscore the relevance of sleep in clinical outcomes in the treatment of cocaine dependence. (C) 2014 Elsevier Ireland Ltd. All rights reserved.