Efficacy and safety of home-based transcranial direct current stimulation (tDCS) on patients with depressive disorders: a systematic review and meta-analysis of randomized clinical trials.

Depressive disorders, including major depressive disorder, impair functioning and affect 280 million people globally. Traditional treatments are not fully effective. Transcranial direct current stimulation (tDCS) offers a noninvasive alternative. Home-based tDCS shows promise for treating depression, requiring systematic review to assess its reliability and efficacy. Six digital databases (Scopus, PubMed, Web of Science, Cochrane, PsycINFO, and CINAHL Complete) were searched for English-language records from inception to November 2024. Inclusion criteria involved randomized controlled trials (RCTs) assessing the effect of home-based tDCS on patients with depressive disorders. The Cochrane Collaboration's tool was used to evaluate the quality of the included studies. From an initial 507 studies, five RCTs with 415 depressed patients were included. Four studies analyzed Montgomery-Åsberg Depression Rating Scale (MADRS) scores in 269 patients, revealing that active tDCS significantly reduced depression scores compared to sham (weighted mean difference [WMD]: - 2.74 [-4.19, - 1.29], I² = 0.00%). Similarly, four studies involving 438 patients assessed Hamilton Depression Rating Scale (HAM-D) scores, showing that active tDCS led to greater reductions in depression scores than sham (WMD: - 2.24 [-4.16, - 1.49], I² = 46.63%). In addition, two studies with 211 participants assessed Hamilton Anxiety Rating Scale (HAM-A) scores, indicating that active home-based tDCS significantly reduced anxiety symptoms compared to sham (WMD: - 1.97 [-3.37, - 0.58], I² = 0.00%). Reported adverse effects of home-based tDCS included skin lesions, pain, burning sensations, increased sensitivity, redness, and mild headaches. This systematic review and meta-analysis showed that home-based tDCS effectively reduces depression and anxiety scores, with significant improvements on MADRS, HAM-D, and HAM-A scales. Future research should include larger samples, better adherence, and long-term efficacy assessments.