Researchers have found a new way to potentially help those suffering from depression. Using electrical currents on the deeper parts of the human brain has been found to ease treatment-resistant depression for as much as two years.
U.S researchers who tested deep brain stimulation, or DBS, on 17 patients, including one woman from Toronto, found the procedure appears safe and that half of patients were in remission after two years of continuous stimulation.
“Many people would say to get some symptom relief — much less a sustained remission in people this profoundly ill — is itself a huge win,” said lead investigator Dr. Helen Mayberg, a professor of psychiatry and neurology at Emory University School of Medicine in Atlanta, Georgia.
None of the patients who reached remission relapsed as long as the device was on, suggesting that DBS, somehow, is stabilizing the brain, she said.
“Once you have the right setting, it’s like setting a pacemaker — the brain shows more normal responses,” she said. “It’s back to being functional.”
The study builds on experiments born in Canada and led by Mayberg and Toronto neurosurgeon Dr. Andres Lozano and psychiatrist Dr. Sidney Kennedy. Theirs was the first to show DBS can help patients with major depression.
Mayberg and the Emory team expanded their new study to include patients with bipolar II disorder. With classic bipolar, or manic depression, people experience extreme swings between depression and fullblown mania. With bipolar II, people suffer milder forms of mania, called hypomania.
Mayberg, a neurologist, has been studying depression since the mid-80s. Working from brain scans, she began noticing a pattern of brain changes that occurred with recovery.
“There were changes you saw in people who got well that you didn’t see in people who didn’t get well,” Mayberg said. “You saw them across different treatments — you saw them even in people who got better if they got a placebo pill.”
They zeroed in on a brain region known as Area 25 that seemed to play a pivotal role in controlling negative moods, even in healthy people.
“If you think of something profoundly negative — if you think of someone dying, or getting sick or a loss — and you take a picture of the brain, the area that changes its activity the most is Area 25,” Mayberg said. “That Area 25 just kept reappearing — as we started to see it, it was kind of everywhere.”
All 17 patients in the new study had failed a minimum of four treatments, including electroconvulsive, or “shock” therapy. They had been depressed, on average, four years.
“These people are off the grid,” Mayberg said. Chronic depression that doesn’t respond to standard treatments can be so profoundly disabling, she said, “people can’t get out of it.”
Deep brain stimulation involves entering the brain through a quarter-sized opening in the skull and carefully implanting thin wire electrodes on either side of the brain. Patients are placed in a head frame that’s fitted to their skull and then attached to the operating table. They’re also awake.
About 70 per cent reported a response as soon as the electrodes were switched on in the operating room.
“They say things like they feel lighter, they feel more connected,” Mayberg says. “The mental churning or mental pain is gone.”
Once the electrodes are anchored in place, patients are given a general anesthesia. The surgeon tunnels under the skin to connect the ends of the electrodes to an implantable battery placed beneath the collarbone. The current is adjusted using a handheld computer.
Patients were told after surgery that they would be randomized to receive either real or “sham” stimulation (meaning no stimulation) for four weeks. In fact, all received the sham treatment; none of their stimulators were turned on. There was a modest, but not clinically meaningful improvement in symptoms.
After the four weeks of sham treatment came six months of active stimulation.
Overall, 41 per cent of patients experienced an improvement in symptoms after six months.
After one year, 36 per cent of patients experienced remission; another 36 per cent saw response — meaning at least a 50 per cent improvement — on a test that measures mood, sleep problems and other symptoms of depression.
After two years of stimulation, 58 per cent experienced remission and 92 per cent a clinical response.
Mayberg says DBS doesn’t make people happy. Instead, “we seem to be removing that deep, dark negative empty sadness — that interference that is so profound that it totally hijacks your brain from doing anything else.”
Patients seem to go through two phases, she said: First comes the realization, she said, that the mental pain that made them constantly think they might be better off dead is gone.
Then they think, “What do I do now?” Mayberg says patients need rehabilitation to help make a full recovery.
The study, published in Archives of General Psychiatry, was small, and exactly how DBS might be working isn’t yet fully known. In addition, the surgery itself carries a risk of hemorrhage, stroke, seizures, infection, a break in the wires and, in rare cases, death from the general anesthesia.
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