Deep brain stimulation increases impulsivity in two patients with obsessive–compulsive disorderLuigjes, Judya; Mantione, Mariskaa; van den Brink, Wima; Schuurman, P. Richardb; van den Munckhof, Pepijnb; Denys, Damiaana,cInternational Clinical Psychopharmacology: November 2011 - Volume 26 - Issue 6 - p 338–340 doi: 10.1097/YIC.0b013e32834af505 Case Report Abstract Author Information Deep brain stimulation (DBS) is an adjustable, reversible, nondestructive neurosurgical intervention using implanted electrodes to deliver electrical pulses to areas in the brain. DBS has recently shown promising results as an experimental treatment of refractory obsessive–compulsive disorder (OCD). The novelty of the treatment requires careful observation of symptoms and possible side effects in patients. This case report describes two patients with treatment-refractory OCD in whom increased voltage of deep brain stimulation targeted at the nucleus accumbens increased impulsivity. Voltage increase of stimulation resulted in an immediate inflation of self-confidence, irritability and impulsive behaviour and was reversed only after lowering the voltage. The mechanisms behind DBS are not yet fully understood. Possibly, stimulation in the area of the nucleus accumbens affects the corticostriatal circuitry, which plays an important role in impulsivity. Location and amplitude of stimulation might be critical in inducing these behaviours. These two cases underline the importance of a careful clinical assessment of impulsive behaviours during DBS for OCD. aDepartment of Psychiatry bDepartment of Neurosurgery, Academic Medical Center, University of Amsterdam cInstitute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands Correspondence to Judy Luigjes, Department of Psychiatry, Academic Medical Center, University of Amsterdam, PA3.227, PO Box 22660, 1100DD Amsterdam, The Netherlands Tel: +31 208 913 706; fax: +31 208 913 701; e-mail: email@example.com Received June 20, 2011 Accepted July 14, 2011 © 2011 Lippincott Williams & Wilkins, Inc.