DBS for Psychiatric Disorders: Lessons from Movement Disorders

The history of surgical treatments for neurologic and psychiatric disorders extends back almost to the turn of the previous century.  Early explorations of surgical lesioning were largely empiric and, sometimes, serendipitous.  Surgical procedures carried out in the 1950s and 1960s were largely abandoned, however, with the discovery of levodopa treatment for Parkinson’s disease and the introduction of antidepressants and narcoleptics for psychiatric disorders.  The public’s negative reaction to excesses of what was called “psychosurgery’” was also a significant factor.  Over the past decades there has been a resurgence of neurosurgical treatments both for movement and psychiatric disorders, such as obsessive compulsive disorder, refractory depression and Tourette’s.  This resurgence began first using classical lesioning techniques but has been largely replaced  by the less invasive, reversible and adjustable technique of continuous electrical deep brain stimulation (DBS). The reasons for this include: 1) the well-recognized success with DBS for movement disorders such as Parkinson’s disease and tremor, 2) the better understanding of the underlying disturbances of brain circuitry and mechanisms in these disorders and the rational for surgical approaches, 3) the unmet need for more effective treatments and 4) combined pressure from desperate patients and families, dedicated psychiatrists and neurosurgeons and device manufactures.  Preliminary successes with early experimental trials of DBS for psychiatric disorders offer promise and hope for relief for some of the most devastating disorders affecting patients.   It is critical, however, that we be ever mindful of the earlier shortcomings of psychosurgery, the lessons from treating movement disorders,  the need for careful and ethical conduct of research and clear communication with the media. The lessons learned from DBS for movement disorders include the importance of a dedicated and well trained team, the need for careful exploration and long term testing of different surgical targets before converging on a single target, the need for study of optimal stimulation parameters, and the recognition of delayed responses and complications. With notable exceptions, the problems and issues associated with surgical interventions are far more complex for psychiatric than for movement disorders, because of the pervasive and long-standing  preoperative disturbances of psychosocial development , mood, and behavior and the resulting greater difficulties with postoperative reintegration into family and society.