Contingency management targeting abstinence is effective in reducing depressive and anxiety symptoms among crack cocaine-dependent individuals

Abstract

© 2017 American Psychological Association. Although contingency management (CM) is effective in promoting abstinence and treatment retention among crack cocaine users who meet the criteria for cocaine dependence, less is known about its off-target effects. In this secondary analysis, we evaluated the impact of CM on depressive and anxiety symptoms in a sample of cocaine-dependent individuals under treatment. Sixty-five crack cocaine users who met the criteria for cocaine dependence were randomly assigned to receive 12 weeks of standard treatment alone (STA; n = 32) or 12 weeks of standard treatment plus CM (STCM; n = 33). The outcome measures of the secondary analysis were depressive and anxiety symptoms assessed with the Beck Depression Inventory-II (BDI-II) and the Beck Anxiety Inventory (BAI). At baseline, 59 (90.8%) of the participants reported at least mild depressive symptoms and 47 (72.5%) reported at least mild anxiety symptoms. The mean BDI-II (24.5 ± 12.1) and BAI (20.7 ± 13.5) scores in the sample as a whole was moderate. After treatment, the reported levels of depressive symptoms (β -9.6, p < .05) and anxiety symptoms (β -9.9, p < .05) were lower among the individuals receiving STCM than among those receiving STA. This study provides evidence that an STCM intervention targeting crack cocaine abstinence also produces significant reductions in depressive and anxiety symptoms. This low cost intervention also demonstrated significant promise and optimization potential for crack cocaine users in a setting of scarce resources and high mental health comorbidity. Relevance Statement: We found that the prevalence of depressive and anxiety symptoms were extremely high among crack cocaine users, and that, among such individuals, contingency management (CM) reduced depressive and anxiety symptomatology to a greater degree than did standard treatment. Our results suggest that CM targeting crack cocaine abuse can have off-target effects on psychiatric symptomatology.