Opioid dependence remains a significant medical and social issue, with opioid agonist maintenance therapy (OAMT) using methadone being the primary treatment approach in Ukraine. However, the potential impact of methadone on cognitive functioning continues is a matter of scientific debate. This study aimed to evaluate the cognitive outcomes of OAMT and the effectiveness of psychocorrective and rehabilitation interventions in patients with opioid dependence. A total of 150 patients were examined and divided into two groups: the main group (n = 101; OAMT + psychotherapeutic and psychocorrective interventions) and the comparison group (n = 49; OAMT only). Cognitive functioning was assessed using the MoCA scale, the SCL‑90-R questionnaire, and the WHOQOL-BREF. At baseline, mild cognitive impairment was observed in 54.67 % of participants, more frequently in the comparison group. After intervention, the proportion of patients without cognitive deficits significantly increased in the main group (59.3 % vs. 15.8 % in the comparison group), while mild impairment predominated in the control group (81.6 %). After the intervention, MoCA scores in the main group were 26.0 [25.0; 27.0] points, and in the comparison group — 24.0 [23.0; 25.0] points, i.e. there was a decrease in the variability of the results in both groups, with a greater concentration of high scores in patients receiving multicomponent treatment. The between-group difference remained statistically significant (p< 0.05). The calculated Cohen’s d (~0.5) indicates a moderate effect size of the psychocorrective intervention. These findings demonstrate the positive impact of a multicomponent treatment approach that combines OAMT with psychotherapeutic programs, contributing to improved cognitive functioning and enhancing the effectiveness of patient resocialization.