Pacemaker 'cure' for depression

Published on 28/02/2005 00:28

SCIENTISTS claim to have developed a "brain pacemaker" that can cure depression through an electronic stimulus.

The discovery raises hopes for thousands for release from depression by drilling holes into their skull and attaching electrodes to the brain which create a brighter mood.

But psychiatrists warn such "surgery" is a drastic measure that must be used with caution.

Scientists in Toronto studied six patients who had suffered years of untreatable clinical depression. Four women and two men had electrodes planted deep into their brain to stimulate one of the areas involved in mood control.

Each underwent local anaesthetic before doctors drilled two small holes in their skulls. Then, using magnetic resonance imaging to guide them, doctors inserted two thin electrode wires into the brain area. The other ends of the wires were threaded under the scalp down to the lower neck area.

Next, the patients underwent a general anaesthetic to have a pulse generator implant, the "pacemaker", sewn in under the skin of their chest. The wires were hooked up to this to provide constant brain stimulation.

The procedure has been used before for extreme cases of Parkinson’s disease to neutralise the brain impulses that cause patients to have the constant tremors.

The results, to be unveiled this week in the American neuroscience journal Neuron, have been described by those involved as a "miracle".

All six volunteers reported acute effects once the current was switched on. These included a sudden brightening of the room and a "disappearing of the void".

Prior to treatment the patients had failed to respond to conventional therapy such as electroconvulsive therapy (ECT) or psychotherapy.

But after undergoing the 10,000 operation, some of the patients reported significant improvements. One woman in her forties, who previously suffered such lethargy she would not answer the telephone, started a business dealing in antiques. A former competitive cyclist started going to the gym to get himself back in shape and a woman struggling to cope with her children became active in her local parent-teacher association.

Dr Helen Maybery, a neurologist now based at the Emory University School of Medicine in Atlanta, Georgia, who led the research, said: "These people were not just having a bad day. They were beyond suicidal; they were too apathetic and disengaged to be bothered. They described their state as dead and deader.

"I see depression as a brain disease not as a chemical imbalance like most psychiatrists. The brain is not a bowl of soup. You cannot just add a chemical and stir. It is a very intricate wiring system. Some circuits were not working for these people.

"Once we turned on the stimulator, the changes were astounding."

Two of the six, both men, lapsed back into depression within six months. But the scientists believe that fine-tuning the implant treatment could eventually cure most cases of severe depression.

Clinical depression affects 20 per cent of Britons at some time in their lives and up to 2.3 million have the condition at any one time.

Professor Vince Egan, a clinical psychologist at Glasgow Caledonian University, welcomed the development. He said the treatment could provide an alternative to ECT - an extreme cure for clinical depression.

"There are different magnitudes of depression," he said. "Someone who has reactive depression based on a supposition of how the world works benefits from cognitive or behavioural therapy.

"For other individuals who have biological features of depression - perhaps inertia or a sense of hopelessness - they benefit from drugs like Prozac. But for those who have biological features of depression who do not respond to drugs, who have previously been treated using ECT, then something less drastic or violent or understood has got to be a good thing."

But he urged caution about any "apparent panacea" that promises a release from depression. "In terms of the majority of depression it is rather dramatic giving people neurosurgery," he said.

He added that doctors must continue to take account of outside causes such as a traumatic upbringing, even in severe cases of depression.

He pointed out people cannot always "run away" from depression by seeking medical treatment as a low mood is sometimes a signal something is wrong in their lives which must be worked out through other means.