According to the results of a new study, the once-controversial method of beaming magnetic fields into the frontal areas of the brain saw one third of the 1132 patients with severe depression go into remission.

Mr Campbell admits he was apprehensive about TMS initially but decided to go ahead with the trial because he wanted relief from the same debilitating condition that had dogged his father and stolen his brother at age 45.

Over the years, Mr Campbell had tried psychologists, psychiatrists and a range of medications. But none of these approaches addressed the deep-rooted emotions he said were always there.

"They addressed the symptoms but not the root cause," he said. "It got to the point where I'd have done anything."

It was his psychiatrist who suggested he try a TMS clinical trial run by Paul Fitzgerald, psychiatrist at The Alfred and Monash University.

As part of the trial, Mr Campbell had 30 treatments over four weeks, each of them lasting 20 minutes.

Three weeks in, his wife Sue Campbell was the first to notice a shift in his personality. He began interacting with his family more and appreciating the small things, such as a sunny day.

"It was the little things, I felt lighter," he said.

Professor Fitzgerald, the lead author of the study reviewing 15 years' worth of trial results, said it was the first time transcranial magnetic stimulation had been assessed as a treatment for depression on this scale.

Results showed that patients with recurrent rather than single-episode depression or those with less severe depression had a greater response rate to the treatment.

Professor Fitzgerald also said treatment at a higher stimulation intensity delivered improved response rates.

Older patients also responded better, a finding that Professor Fitzgerald said was scientifically and clinically important.

"We really shouldn't avoid use of TMS in older patients," he said.

The patients participating in the clinical trials were aged 18 to 89. All had been diagnosed with severe depression that could not be treated with traditional medication.

Professor Fitzgerald said the Australian and Canadian research was valuable because it provided an insight into which patients would respond to TMS and which would not.

"It has had a number of direct impacts on how we treat patients," he said.

Professor Fitzgerald said TMS had the potential to treat other disorders, such as post traumatic stress disorder, obsessive compulsive disorder and even Alzheimer's disease. To read more click here. For help or information visit beyondblue.org.au, call Suicide Helpline Victoria on 1300 651 251, or Lifeline on 131 114.