Bipolar disorder and ASPD were the only psychiatric disorders associated with any index of cocaine dependence severity. The finding that both were associated with more days of cocaine use during the period of heaviest cocaine use suggests that severe Axis I or Axis II morbidity may exacerbate cocaine use during heavy periods of use by cocaine dependent individuals. This findings is consistent with recommendations that ASPD (Compton et al., 2005a) and bipolar disorder (Weiss et al., 2007) be carefully assessed in cocaine dependent persons. This has treatment implications, since patients with comorbid ASPD and cocaine dependence were more likely to be abstinent from cocaine immediately after treatment and at six-month and one-year follow-up if they received a contingency management intervention in combination with methadone maintenance than if they received methadone maintenance alone (Messina et al., 2003). The need for differential treatment based on ASPD comorbidity was suggested by findings that cognitive behavior therapy was not effective in cocaine dependent patients with comorbid ASPD but was more effective than contingency management with non-ASPD cocaine dependent patients (Messina et al., 2003).
