Background: Obsessive-compulsive disorder (OCD) is a chronic condition that significantly impacts patients’ lives. Various treatments, including pharmacological, behavioral, and brain stimulation methods, are employed. Recent studies indicate that transcranial alternating current stimulation (tACS) effectively alleviates OCD symptoms, warranting further investigation into its therapeutic potential.
Methods: A 4-week study at the Tertiary Center of Psychiatry and Behavioral Science in Southern Iran evaluated the effectiveness of tACS for treating OCD in participants aged 18–60. The treatment involved bi-weekly sessions targeting frontal brain areas, assessing various psychological metrics. Results indicated a significant improvement in specific measures. All participants met predefined therapy-resistance criteria based on documented non-response to evidence-based pharmacotherapy and/or structured CBT prior to enrolment.
Results: Ninety-five patients were screened, and five eligible participants with OCD (ages 18–46; four female) completed the intervention. All had severe baseline symptoms (Y-BOCS ≥ 23). Obsessive–compulsive symptoms showed consistent improvement, with mean Y-BOCS decreasing from 28.4 ± 4.16 to 18.4 ± 6.34 (35.2% reduction). CGI-S scores declined from 5.4 ± 0.89 to 4.6 ± 1.14, and the mean CGI-I score was 2.6, indicating notable clinical improvement. Affective symptoms improved substantially: total DASS-21 scores decreased by 46.4%, including reductions in stress, depression, and anxiety. SBQ-R scores also declined (− 16.7%). Cognitive performance showed generally favorable trends, with improvement in TOLT planning scores. No major adverse effects were reported, aside from mild irritation and brief flashing sensations.
Conclusions: Our pilot study on therapy-resistant OCD with tACS yields promising initial results and safety. However, limitations stress cautious interpretation, necessitating larger, controlled trials for validation and refinement.
Clinical trial number: Not applicable.
Supplementary Information: The online version contains supplementary material available at 10.1186/s12888-026-07838-z.
Keywords: Noninvasive brain stimulation; OCD; Psychiatry; Therapy-Resistant OCD; tACS.