Transcranial magnetic stimulation for depression and other psychiatric disorders

Introduction. Repetitive transcranial magnetic stimulation (rTMS) has been proposed as a possible alternative to electroconvulsive therapy for the tre atment of selected patients with depression, bipolar affective disorder and schizophrenia. The aim of this study was to evaluate the evidence for the effectiveness of rTMS in mood disorders and schizophrenia. Methods. Studies were identified using MEDLINE (1966 to January 2000), EMBA SE/Excerpta Medica (1980 to January 2000), Biological Abstracts and Index t o Scientific and Technical Proceedings. A number of biomedical and TMS rela ted websites were also searched. We estimated the number needed to treat to show beneficial effect of rTMS when compared with the placebo controlled g roup. Results. Seven controlled trials of rTMS depression were identified. Five o f these were suitable for meta-analysis and show a beneficial effect of rTM S compared to placebo, with a number needed to treat of 2(.)3 with a 95% co nfidence interval 1(.)6 to 4(.)0, total; 81 patients. A single trial of rTM S has also been performed in mania, which shows a beneficial effect of righ t hemisphere stimulation when compared with left hemisphere stimulation. A controlled trial in schizophrenia failed to show any benefit of rTMS. Discussion. rTMS has demonstrable beneficial effects in depression. The ext ent and the duration of the anti-depressant effect of rTMS has yet to be de fined. There now needs to be randomized controlled trials to compare rTMS d irectly with standardized electroconvulsive therapy in order to take this s ubject forward. With regard to the treatment of other mood disorders and sc hizophrenia, we are at an early stage in the assessment of further studies that are needed to examine any potential role for rTMS.