Monitoring adverse effects in TMS: From controlled trials to clinical reality

Transcranial magnetic stimulation (TMS) is a non-invasive treatment for psychiatric and neurological disorders, especially major depressive disorder. While generally well-tolerated and associated with fewer side effects than pharmacological alternatives, TMS is not without risks. Common adverse effects include transient headaches, scalp discomfort, nausea, and dizziness. Seizures, the most serious event, are rare (7 per 100,000 sessions) and typically occur early in treatment among high-risk individuals. Psychological side effects, particularly nocebo responses, are underexplored and warrant attention due to their potential impact. Cognitive side effects are rare and typically mild or transient, with some evidence of cognitive benefit in specific protocols. With expanding clinical use, standardized monitoring tools and open-access registries are needed to ensure accurate reporting and transparency.