Transcranial alternating current stimulation for major depressive disorder: An updated systematic review and meta-analysis of randomized trials with GRADE assessment.
Yehia Nabil, Khaled Abdalla Moghib, Zeyad Tarek et al.
✦ AI-curated · Sources linked
In 30 seconds
This systematic review and meta-analysis assessed efficacy, follow-up outcomes, tolerability, and safety of transcranial alternating current stimulation (tACS) in adults with major depressive disorder. It included 11 reports from nine randomized trials, comparing active tACS mainly with sham or inactive control. Active tACS was associated with higher odds of treatment response (OR 2.41, 95% CI 1.28-4.56) and remission (OR 4.69, 95% CI 2.37-9.28), but did not significantly reduce clinician-rated mean symptom severity. Evidence certainty ranged from very low to moderate.
Key findings
- Clinician-rated symptom severity did not differ significantly from control: MD -1.80, 95% CI -4.80 to 1.20; I 2 = 89.8%.
- Treatment response was more likely with active tACS: OR 2.41, 95% CI 1.28-4.56.
- Remission was more likely with active tACS: OR 4.69, 95% CI 2.37-9.28.
- At least one adverse event was more likely with active tACS: OR 1.95, 95% CI 1.12-3.41.
Why it matters
The findings suggest that response and remission outcomes may improve even though pooled mean symptom severity did not show a significant benefit. The distinction matters when interpreting efficacy across trials, particularly because stimulation protocols varied and heterogeneity was substantial. Safety estimates also indicate a higher likelihood of experiencing at least one adverse event, while evidence certainty remains limited.
What to keep in mind
The evidence base was small, certainty ranged from very low to moderate, and substantial heterogeneity affected the symptom-severity analysis. Limited data for protocol-specific subgroup analyses and heterogeneous stimulation parameters constrain interpretation.