Background and Objective: Patients under methadone maintenance therapy (MMT) are susceptible to several complications including mental disturbances and risk of relapse. The present study was designed to evaluate the effects of tDCS on relapse, depression, and anxiety of opioid-dependent patients under methadone maintenance treatment (MMT). Methods: It was a randomized-clinical trial that conducted among 27 male patients referred to the outpatient addiction clinic of Ibn-e-Sina psychiatric hospital in Mashhad from July 2018 to May 2019. Participants were allocated to two treatment groups including intervention and sham groups. The intervention group received seven sessions of tDCS, in the F3 (cathode) and F4 (anode) areas of the brain, each one lasts 20 min, in two consecutive weeks. Depression, anxiety, and stress scale-21 (DASS-21) were measured before, during, and after the intervention in patients under MMT. Relapse on the morphine, cannabis, and methamphetamine was screened by urine dipstick tests of morphine, cannabis, and methamphetamine. Results: Depression, anxiety, and stress of participants were significantly reduced in the intervention group compared with the control after the seventh session of tDCS (P < 0.001, P=0.01, and P=0.01, respectively). In addition, the relapse rate showed no significant changes between the two groups (P=0.33). Conclusion: Overall, our study demonstrated that depression, anxiety, and stress of participants were significantly reduced after the seventh session of tDCS, but did not affect

Background: Patients under Methadone Maintenance Therapy (MMT) are susceptible to several problems, including sleep disturbances and risk of relapse. The present study aimed to assess the effect of transcranial direct current stimulation (tDCS) on sleep quality of addicts under MMT.Methods: This clinical trial was conducted on 27 male patients who underwent maintenance methadone therapy in MMT clinics of Mashhad City, Iran. They were divided into the experimental and sham groups. The experimental group received seven 20-min sessions of tDCS every other day. In the sham group, the electrical current was delivered for a few seconds, but the electrodes were remained to the end of the session. Sleep quality was measured at baseline, during, and after the intervention by Pittsburg Sleep Quality Index (PSQI). The obtained data were analyzed by descriptive statistics such as mean and standard deviation and inferential statistics, such as t test, Chi-square, Mann Whitney, and Fischer exact test in SPSS v. 25.Results: The difference between the two groups after tDCS in sleep duration was significant (P=0.04). In the experimental group, the total score of sleep had a reducing trend (P<0.000), while in the sham group, the overall score in 3 phases of evaluation had no significant change (P=0.19). However, the rate of inappropriate sleep quality was not significant between the two groups after the intervention (P=0.12).Conclusion: This trial demonstrated the positive effect of tDCS on sleep quality in patients under MMT programs. Further studies are needed to confirm our findings.