Treating chronic depression using magnetic stimulation

Almost a third of people diagnosed with clinical depression do not respond to medication or talk therapy. A potential treatment for this chronic or treatment-resistant depression is Repetitive trans-cranial magnetic stimulation (rTMS) which has been used overseas for more than a decade. Dr Nicholas Hoeh from the University of Auckland's Faculty of Medical and Health Sciences is lead researcher on the first clinical study of its use in New Zealand. So how does it work, and who could it help?