Transcranial direct current stimulation (tDCS) is a minimally invasive form of brainstimulation that uses direct electrical current to alter cortical excitability. During thisprocess, a weak, direct electrical current (1 to 2 mA) is applied using scalp surface electrodes.Anodal stimulation increases cortical excitability and cathodal stimulation decreases it. Thechanges in cortical excitability probably arise from the depolarization and hyperpolarization ofneurons.1 Interest in this treatment modality had begun way back in the 1960s but graduallywaned. Renewed interest began emerging in the 1990s following spurt in neuromodulationresearch using transcranial magnetic stimulation (TMS). Based on the theory of hypoactivityin left prefrontal cortex in depression, anodal tDCS has been applied to the left hemisphere toincrease activity and cathodal tDCS to the right hemisphere to decrease activity in order toresolve depression. Several open label and randomized controlled trials have been conductedto examine the efficacy of tDCS in treating major depression some of which have yieldedpositive results.2, 3, 4, tDCS has also been tried in Parkinson’s disease, schizophrenia, posttraumatic stress disorder and substance use. 5, 6,7 tDCS is a cheap and non-invasive techniquewith minimal side effects like headache and itchiness and redness at the site of stimulation.It will require few years of systematic research to find out whether tDCS emerges as a cheap,non-invasive and above all, effective method for treatment of psychiatric disorders or it goesinto oblivion as another “fancy” brain gadget!REFERENCES1. Bindman LJ, Lippold OC, Redfearn JW. The action of brief polarizing currents on the cerebral cortex ofthe rat (1) during current flow and (2) in the production of long-lasting after-effects. J Physiol. 1964; 172 :369-382.2. Boggio PS, Rigonatti SP, Ribeiro RB, et al. A randomized, double-blind clinical trial on the efficacy of cortical direct currentstimulation for the treatment of major depression. Int J Neuropsychopharmacol. 2008; 11 : 249-254.3. Brunoni AR, Ferrucci R, Bortolomasi M, et al. Transcranial direct current stimulation (tDCS) in unipolar vs. bipolar depressivedisorder. Prog Neuropsychopharmacol Biol Psychiatry. 2011; 35 : 96-101.4. Fregni F, Boggio PS, Nitsche MA, et al. Cognitive effects of repeated sessions of transcranial direct current stimulation in patientswith depression. Depress Anxiety. 2006; 23 : 482-484.5. Kuo MF, Paulus W, Nitsche MA. Therapeutic effects of non-invasive brain stimulation with direct currents (tDCS) in neuropsychiatricdiseases.Neuroimage. 2014; 85 : 948-9606. Jansen JM, Daams JG, Koeter MW, etal.Effects of non-invasive neurostimulation on craving : a meta-analysis. Neuroscience BiobehavRev 2013; 37 : 2472-24807. Marin MF, Camprodon JA, Dougherty DD, et al. Device-based brain stimulation to augment fear extinction : implications for PTSDtreatment and beyond. Depress Anxiety 2014; 10 : 1-10