Decision-Making Processes in Drug-Abusers Before and After Maintenance Treatment with Methadone

The aim of this study is to assess risk taking in opioid dependents and to analyze the effect of methadone maintenance treatment (MMT) on the improvement of cognitive structure of possible disorders, using computational modeling methods. In this research the decision making processes of five groups of participants (male controls, female controls, opioid dependents before treatment, dependents after three months of MMT and dependents after six months of MMT) were analyzed using Persian computer based version of balloon analogue risk task. Results obtained from the test scores showed that the function of male and female controls do not differ significantly, however riskful decision making in dependents before treatment, is higher than that of male controls. Also, the degree of risk taking of dependents after six months of treatment, was lower in comparison with other groups of dependents. Therefore, MMT could affect the amelioration of the imbalance in risk taking behavior. In this study, we used cognitive modeling in order to describe different decision making processes to explore the causes of differential functioning among groups. Analysis of estimated parameters demonstrate that imbalance in reward dependence generates risk taking behaviors in the drug abuser group. In addition, this group pays less attention to their evaluation of choices; hence, a more haphazard behavior. On the other hand, the control group chooses the alternatives that considers more valuable based on the evaluation of gains and losses.