PILOT STUDY OF THE CLINICAL AND COGNITIVE EFFECTS OF HIGH-FREQUENCY MAGNETIC SEIZURE THERAPY IN MAJOR DEPRESSIVE DISORDER

Background Electroconvulsive therapy (ECT) is a very commonly used treatment for patients with severe and treatment-resistant depression. Although effective, this treatment is complicated by a number of side effects including cognitive impairment motivating attempts to develop treatment alternatives. Magnetic seizure therapy (MST) is a brain stimulation technique using a high-powered transcranial magnetic stimulation device to produce therapeutic seizures. Preliminary research suggests that MST has antidepressant activity in the absence of cognitive side effects. The aim of this study was therefore to investigate the therapeutic efficacy and cognitive profile of MST provided at high frequency (100 Hz) and potentially longer stimulation trains and longer treatment courses than have been previously investigated. Methods Thirteen patients participated in an open-label clinical trial of up to 18 treatment sessions with 100-Hz MST. Assessments of depression severity and cognitive functioning were performed before and after treatment. Results Of the 13 patients who completed the study, five met clinical response criteria at study end. There was an overall group reduction in depression severity and no evidence of any impairment of orientation, memory, or other elements of cognition after MST treatment. The major limitation of the study was its lack of sham control. Conclusions In conclusion, MST shows antidepressant efficacy without apparent cognitive side effects. However, substantial research is required to understand the optimal conditions for stimulation and to compare MST to established treatments including ECT.