Informed consent for clinical trials of deep brain stimulation in psychiatric disease: challenges and implications for trial design

Advances in neuromodulation and an improved understanding of the anatomy and circuitry of psychopathology have led to a resurgence of interest in surgery for psychiatric disease. Clinical trials exploring deep brain stimulation (DBS), a focally targeted, adjustable and reversible form of neurosurgery, are being developed to address the use of this technology in highly selected patient populations. Psychiatric patients deemed eligible for surgical intervention, such as DBS, typically meet stringent inclusion criteria, including demonstrated severity, chronicity and a failure of conventional therapy. Although a humanitarian device exemption by the US Food and Drug Administration exists for its use in obsessive-compulsive disorder, DBS remains a largely experimental treatment in the psychiatric context, with its use currently limited to clinical trials and investigative studies. The combination of a patient population at the limits of conventional therapy and a novel technology in a new indication poses interesting challenges to the informed consent process as it relates to clinical trial enrollment. These challenges can be divided into those that relate to the patient, their disease and the technology, with each illustrating how traditional conceptualisations of research consent may be inadequate in the surgical psychiatry context. With specific reference to risk analysis, patient autonomy, voluntariness and the duty of the clinician-researcher, this paper will discuss the unique challenges that clinical trials of surgery for refractory psychiatric disease present to the consent process. Recommendations are also made for an ethical approach to clinical trial consent acquisition in this unique patient population.