Decision-making processes as predictors of relapse and subsequent use in stimulant-dependent patients.

Decision-making processes have been posited to affect treatment outcome in addiction patients. This multi-site study assessed whether two measures of decision-making predicted relapse and subsequent use in stimulant-dependent patients. A total of 160 methamphetamine- or cocaine-dependent patients participating in a multi-site clinical trial evaluating a modified 12-step facilitation intervention for stimulant-dependent patients (NIDA Clinical Trials Network protocol CTN-0031, STAGE-12) were assessed. Decision-making processes of risk and delay (Iowa Gambling Task (IGT)) and response reversal (Wisconsin Card Sorting Task (WCST)) were obtained shortly after treatment admission followed by assessment of stimulant use over the next six months. The relationships of the IGT and WCST (Perseverative Errors) with relapse (yes/no) and days of stimulant use during the period following post-randomization were evaluated.

Performance on the IGT and WCST did not significantly predict relapse status or time to relapse. Unexpectedly, worse performance on the IGT was associated with fewer number of stimulant use days (p=0.001). In contrast, worse performance on the WCST (fewer perseverative errors) was associated with a greater number of stimulant use days (p=0.0003). The predictive effects of perseverative errors on subsequent use were confined to methamphetamine-dependent and minority participants.

Conclusions: Decision-making processes, as measured in the current study, do not uniformly predict relapse or subsequent use. A decrease in the salience attribution of non-drug reinforcers may explain the positive relationship between IGT performance and post-relapse use. More comprehensive and global measures of impulsiveness may better assess relapse risk and use.

Related protocols: CTN-0031