The Effect of Transcranial Direct Current Stimulation on Relapse, Anxiety, and Depression in Patients With Opioid Dependence Under Methadone Maintenance Treatment: A Pilot Study

Background and objective: Transcranial direct current stimulation (tDCS), a non-invasive form of neuromodulation, has been suggested as a new potential treatment strategy for drug dependence. 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 was performed on 27 participants referred to the outpatient addiction clinic of Ibn-e-Sina psychiatric hospital in Mashhad from November in 2018 to February in 2019. Participants were selected via the convenient sampling method and randomly assigned to intervention and control groups. The intervention group received seven sessions of tDCS, in the F3 (cathode) and F4 (anode) areas of the brain, each one lasts 20 minutes, in 2 consecutive weeks. We used Depression, Anxiety, and Stress Scale-21 (DASS-21) to measure depression, anxiety, and stress of participants. Relapse on the morphine, cannabis, and methamphetamine was screened by urine dipstick tests of morphine, cannabis, and methamphetamine. Results: The level of depression, anxiety, and stress of participants were significantly reduced in the intervention group compared to the control group after the seventh session of tDCS (P=0.00, P=0.01, and P=0.01, respectively). The relapse rate showed no significant changes between the two groups (P=0.33). Conclusion: Seven sessions of right anodal/left cathodal tDCS could effectively decrease the anxiety and depression of patients with opioid dependence under MMT. However, it has no significant effects on the relapse rate.