Table 3 Studies investigated the efficacy of tDCS on individuals with OCD
| Author, year | Study design | Anode and cathode position | Results |
|---|---|---|---|
| Volpato et al., 2013 [32] |
Case report One 35 year-old-male |
Anode: neck; Cathode: F3 2 mA, 20 min daily for 10 days |
• Not effective on OC symptoms • Significant effect on depression and anxiety |
| Silva et al., 2016 [33] |
Case report Two 31 and 37 year-old-males |
Anode: left deltoid muscle; Cathode: pre-SMA 2 mA, 30 min daily for 20 days |
• One participant had no improvement in Y-BOCS, depression, and anxiety • One participant had 55% reduction in Y-BOCS and 50% reduction in depression and anxiety symptoms |
| Mondino et al., 2015 [34] |
Case report One 52 year-old-female |
Anode: right occipital cortex; Cathode: FP1 2 mA, 20 min twice a day for 5 days | • 26% reduction in Y-BOCS |
| Narayanaswamy et al., 2015 [35] |
Case report One 39 year-old-female and one 24 year-old-male |
Anode: left pre-SMA; Cathode: right supra-orbital area 2 mA, 20 min twice a day for 10 days |
• 46.7% reduction in Y-BOCS of male • 52% reduction in Y-BOCS of female |
| D’Urso et al., 2016 [36] |
Case report One 33 year-old-female |
Active: pre-SMA; Reference: right deltoid 2 mA, 20 min daily for 20 days |
• 11% worsening in Y-BOCS after anodal sessions • 30% reduction in Y-BOCS after cathodal sessions |
| Alizadeh Goradel et al., 2016 [37] |
Case report One 23 year-old-female |
Anode: O2; Cathode: left OFC 2 mA, 20 min daily for 10 days | • 64% reduction in Y-BOCS; 87% reduction in depression; and 100% reduction in anxiety symptoms |
| Palm et al., 2017 [38] |
Case report One 31 year-old-male |
Anode: F3; Cathode: F4 2 mA, 30 min twice a day with total 20 stimulations in 2 weeks | • 22% reduction in Y-BOCS |
| Hazari et al., 2016 [39] |
Case report One 24 year-old-male |
Anode: left pre-SMA; Cathode: right supraorbital area 2 mA, 20 min twice a day for 10 days | • 80% reduction in Y-BOCS |
| Dinn et al., 2016 [40] |
Open label trial Four females and one male |
Anode: F3; Cathode: Fp2 2 mA, 20 min daily for 15 days |
• 23% reduction in Y-BOCS but was not maintained at 1 month of follow-up • No reduction in anxiety symptoms and 30% reduction in depression symptoms |
| Najafi et al., 2017 [41] |
Open label trial Twenty three females and nineteen males |
Anode: P1, C3, T7; Cathode: Fp2 2 mA, 30 min daily with total 15 stimulations in 3 weeks | • 79% reduction in Y-BOCS |
| Bation et al., 2016 [20] |
Open label trial Six females and two males |
Anode: right cerebellum; Cathode: left OFC 2 mA, 20 min twice a day for 5 days | • 26% reduction in Y-OBCS |
| D’Urso et al., 2016 [21] |
RCT Seven females and four males |
Active: Cz; Reference: lateral surface of right deltoid 2 mA, 20 min daily for 10 days |
• Cases with anodal stimulation (N = 6) had worsening in Y-BOCS • Cases with cathodal stimulation (N = 6) had 20% reduction in Y-BOCS |
| Yekta et al., 2015 [42] |
Controlled RCT Twenty cases (no data on gender) |
Anode: F4; Cathode: F3 2 mA; 20 min daily for 15 days in experimental group |
• Improved decision-making of experimental group (N = 10) compared to sham control group (N = 10) • No report on Y-BOCS |
| Gowda et al., 2019 [43]; |
Controlled RCT Four females and 21 males | Anode: pre-SMA; Cathode: right supraorbital area 2 mA, 20 min twice a day for 5 days | • Y-BOCS was significantly reduced in experimental group compared to baseline and sham control arm |
| Bation et al., 2020 [44]; | Controlled RCT |
Anode: right cerebellum; Cathode: PF1 2 mA, 20 min twice a day for 5 days |
• Significant acute effect of tDCS in experimental group compared to baseline and sham control arm • No changes in experimental group was observed compared to sham control arm after 1 and 3 months of tDCS stimulation |
