Transcranial magnetic stimulation (TMS) is a relatively non-invasive technique to interfere with the function of small cortical areas through currents induced by alternating magnetic fields emanating from a handheld coil placed directly above the targeted area. This technique has clear effects on a whole range of measures of brain function and has become an important research tool in neuropsychiatry. More recently, TMS has been studied in psychiatry mainly to assess its putative therapeutic effects in the treatment of refractory major depression. Most studies indicate that both low-frequency TMS and higher (20 Hz) frequency repetitive TMS may have some antidepressant properties. This is most interesting and opens a whole new avenue of low invasive techniques to stimulate the brain in major depression. However, definite therapeutic effects of clinical significance still remain to be demonstrated.Zusammenfassung Die transkranielle Magnetstimulation (TMS) ist eine wenig invasive Technik zur Beeinflussung der Funktion kleiner kortikaler Gebiete durch von alternierenden Magnetfeldern induzierte Stro¨me. Diese Magnetfelder werden mit Hilfe einer handgefu¨hrten Spule erzeugt, die unmittelbar u¨ber dem gewu¨nschten Zielbereich positioniert wird. Diese Methode hat deutliche Poiesis