Brain stimulation techniques include transcranial electrical approaches, magnetic approaches and surgical approaches. This chapter reviews research to date on these approaches in the treatment of anxiety disorders, discusses how this work may advance knowledge, and tests hypotheses about the neural circuitry underlying anxiety disorders. Case reports suggest that electroconvulsive therapy (ECT) might be helpful in the treatment of refractory obsessive-compulsive disorder (OCD) as well. Transcranial magnetic stimulation (TMS) was recently approved by the US Food and Drug Administration (FDA) for the treatment of depression, and its potential for treatment of other psychiatric disorders is under study. Deep brain stimulation (DBS) involves delivering a current using implanted quadripolar electrodes connected to a battery-powered pulse-generating device. Sham-controlled trials represent the gold standard for establishing the efficacy of an intervention. An adequate placebo should be plausible and inactive, and it should simulate as closely as possible the ancillary effects of the treatment.