[Transcranial direct current stimulation (tDCS) for obsessive-compulsive disorder: A new treatment option?]

More than 40 % of patients with obsessive-compulsive disorder (OCD) do not respond to established treatments despite advances in psychopharmacology and psychotherapy. Since a couple of years, non-invasive brain stimulation techniques gain importance in the treatment of psychiatric disorders. Transcranial direct current stimulation (tDCS) uses weak constant direct current to modulate neuronal activation and changes the function of neuronal networks. This technique is recently investigated for the improvement of treatment resistant OCD symptoms. In this review we give a concise overview over the current state of the art and delineate further directions of tDCS application in OCD. The search in the NIH database pubmed and further manual search revealed nine case reports, three open label studies and one controlled study with two active arms. There is no sham controlled study yet. A total of 78 patients received active tDCS with a large variety of different electrode placements, with main target over dorsolateral prefrontal cortex, orbitofrontal cortex, and (pre-)supplementary motor areas. Although stimulation parameters were highly heterogeneous, reported cases show not only an improvement of OCD symptoms, but also an improvement of depression and anxiety symptoms in patients with treatment resistant OCD. This evidence is limited by the lack of sham-controlled studies and needs confirmation in larger studies.