Condition

Depression

Depression has the most consistent evidence base for tDCS. Anodal stimulation of the left dorsolateral prefrontal cortex (DLPFC) is associated with an improvement in depressive symptoms greater than placebo (sham), with a small-to-moderate effect size.

What the evidence supports

Multiple randomized, sham-controlled trials and a meta-analysis support an antidepressant effect of active tDCS greater than sham — as a complementary therapy and under professional supervision.

Meta-analysis (Shiozawa et al., 2014; 7 RCTs, n=259): effect size Hedges' g = 0.37 (95% CI 0.04–0.70); response OR 1.63; remission OR 2.5.
International guideline (IFCN, Lefaucheur 2017): Level B — probable efficacy — for anodal left-DLPFC tDCS. No indication receives Level A (definite efficacy).
Fully remote home RCT (Woodham/Fu, Nature Medicine, 2025; n=174): response ~58% vs ~38% with sham, validating remotely supervised home use.
Drop-out comparable to sham; effect of a magnitude comparable to rTMS.

In numbers

Depression

g 0.37

effect size vs. placebo (Shiozawa 2014)

Level B

probable efficacy · IFCN 2017 guideline (no Level A)

58% vs 38%

response vs. placebo · home tDCS (Woodham/Fu 2025)

Strength and limits of the evidence

The evidence has grown and is favourable, but remains bounded and not definitive: individual trials are small, negative double-blind trials exist (Loo 2010, Palm 2012, Blumberger 2012), especially in treatment-resistant depression, and long-term efficacy is still little tested. International guidelines assign at most Level B (probable) — no Level A. The 2025 home trial is promising, but it is a single phase-2 study.

Typical montage and dose

Typical montage: anode over the left DLPFC (F3), contralateral cathode; 2 mA (some studies 1 mA), ~20-minute sessions, 5 to 15 sessions.

Safety

Generally well tolerated, with a drop-out rate comparable to sham. There are rare reports of hypomania/mania, especially in people with bipolar disorder — assessment is up to the healthcare professional.

Sources

Shiozawa P, et al. Int J Neuropsychopharmacol. 2014;17:1443–1452.
Lefaucheur J-P, et al. (IFCN). Clin Neurophysiol. 2017;128(1):56–92.
Woodham RD, et al. Nat Med. 2025;31:87–95.
Boggio PS, et al. 2008 (cited in the Newronika dossier).

Informational, non-promissory content. tDCS is a complementary therapy under professional supervision; results vary between individuals.

Other conditions

Chronic pain & Fibromyalgia

Modulating pain networks to reduce intensity and improve quality of life.

Post-stroke rehabilitation

Adjuvant support to rehabilitation. Recent meta-analyses point to benefit in specific domains — naming (aphasia) and dysphagia; motor function is not established.

How the treatment works See all the evidence

Assess your case with a specialist

tDCS indication is individual and must be made by a healthcare professional. Request a no-commitment quote.