Middle Eastern Journal of Disability Studies

Background & objective: Addiction is a disorder that involves complex relations with cognitive functions. Individuals with history of substance dependence often suffer from impairments in cognitive functions. The present study evaluates the effect of Methadone maintenance treatment (MMT) on cognitive functions of opioid-dependent patients.
Methods: This research is an ex-post facto one. The study population consisted of all opioid-dependent patients and patients undergoing Methadone maintenance treatment in central prison of Hamedan. Convenience sampling was used to recruit 30 participants from among methadone- maintained patients, 30 opium-dependent patients as well as 30 non-dependent participants as the control group. The research instruments were Wechsler Memory Scale (WMS-III) and Stroop test. Analysis of variance (ANOVA) and Tuckey test were used to analyze the data.
Results: The results show no statistically significant difference between methadone-maintained participants and non-dependent participants on Wechsler Memory Scale (p<0.001). Yet, both aforementioned groups were significantly different from opioid-dependent group (p<0.001). On Stroop test, the participants in the control group scored significantly higher than the participants in methadone-treatment group and the opium-dependent group in subscales of congruent error, incongruent error, congruent reaction time, incongruent reaction time (p<0.001).
Conclusion: It can be concluded that Methadone maintenance treatment improves selective attention in opioid-dependent patients.