Non-invasive brain stimulation – a new way forward for psychiatric disorders?

Repetitive transcranial magnetic stimulation (rTMS) is the focal application of a localized, pulsed magnetic field to the cerebral cortex, resulting in the induction of a small electrical currents that stimulate nerve cells in the region of the brain involved in mood regulation and depression. Similar to electroconvulsive therapy (ECT), it is noninvasive, however unlike ECT it does not involve use of an anaesthetic, seizure induction or loss of consciousness. The Professional Practice Guidelines (PPG 16) of the Royal Australian and New Zealand College of Psychiatrists as well as the Interventional procedures guidance [IPG542] of the National Institute of Clinical Excellence (NICE) of the United Kingdom both list depression as the primary clinical indication for rTMS. The PPG 16 also states that there is accumulating evidence for use of rTMS in obsessive compulsive disorder, but given the wide variety of treatment targets and paradigms used in different studies, it is still difficult to make an overall conclusion. The guideline highlights that the evidence for use of rTMS in schizophrenia is less substantive, with lack of multi-centre trials, but may be considered for patients with persistent auditory hallucinations despite optimal medication, to be delivered with specialist training.