Is there a place for non-invasive brain stimulation in the treatment of schizophrenia?

The management of patients with schizophrenia is a complex undertaking informed by a diverse evidence base addressing pharmacological, psychosocial and physical therapies. The journal has recently published a clinical guideline, using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach, to assess the evidence for the effectiveness of a range of treatments, providing a valuable guide to practice and service planning. However, the guideline process did not assess the evidence for forms of non-invasive brain stimulation such as repetitive transcranial magnetic stimulation. Repetitive transcranial magnetic stimulation methods, especially, have been evaluated in studies conducted over 25 years, addressing symptoms experienced by patients with treatment-resistant schizophrenia. Many of these methods have been the subject of recent systematic reviews, meta-analyses and network meta-analyses, including some involving more than 30 studies and well over 1000 patients. Despite the heterogeneity of the literature (including variation in stimulation protocols, sham methods and follow-up), its extent and the conclusions of the studies conducted to date make a clear case that these approaches warrant meaningful consideration, including GRADE appraisal. This evidence is strongest for the use of stimulation of the left temporoparietal junction to reduce treatment-resistant auditory hallucinations, and prefrontal stimulation to modulate negative symptoms, both substantial clinical problems. These new approaches warrant meaningful consideration, alongside those supported in the recently published guidelines.