Deep-brain stimulation for depression

On Sunday morning at New Horizons in Science at Yale -- after some coffee for brain stimulation -- we were treated to our first science talk of the day: on deep-brain stimulation as a treatment for severe depression.

Emory University professor of psychiatry and neurology Helen Mayberg, MD, showed us several brain scans she uses to study moods and neural networks. She can tell from these neural images whether you're glad, mad or sad.

Then, she targets areas of the brain with what she describes as an "implantation of a very, small wire... with electrodes on the end." The electrodes are guided to wherever she wants it in the brain and an IPG is implanted in the chest.

Dr. Mayberg worried about the safety of acute stimulation of areas of the brain. What happens if you stimulate the hypothalamus and it causes a drop in blood pressure? But she couldn't rely on surgeons as "gatekeepers," so she performed intra-operative safety testing.

During the testing, patients self-reported spontaneous feelings such as "intense calm" or resolution of pain and dread -- interoceptive release. These reports happened patient after patient, says Dr. Mayberg, so she knew something was going on. The feelings were followed by interest, energy -- exteroceptive awareness.

Dr. Mayberg's first study was published in 2005, then she expanded and published again in 2008 (in Biol Psych). The studies showed deep-brain stimulation was effective in treatment-resistant depression. "The [patients] not only got better, they stayed better," she says.

She then gave us some preliminary results of an Emory study of active treatment for six months with a two-year follow-up on bipolar and unipolar patients. The results so far look very, very promising. "This is an anti-depressant treatment, not a mood stabilizer," says Dr. Mayberg. "No one remains in pre-treatment state, everyone is on road to recovery."

She says now we know not just where to stimulate in the brain, but what fibers must be impacted for the treatment -- a treatment that can take patients with "gnawing pain" or feelings of "being in a room with 10 screaming children" to a place of a finding serious relief.

So, what's next? Dr. Mayberg says the treatment needs to go through a series of placebo-controlled trials to establish safety and to confirm initial results.

Even more exciting, however, is that with neural images it may be possible to soon predict and even prevent depression. "This is teaching us an amazing amount about depression," Dr. Mayberg says. The more we learn, the greater the understanding of what goes wrong in neural networks that leads to development of severe depressive disorders.

She's careful to point out that a stimulator is not the only thing you need to come out of a depressive state and it's not a device that will ever guarantee that people can forever say goodbye to "bad days."

But along with continual therapy over time, from a patient's perspective, the treatment can mean the difference between feeling like you are at the bottom of the Grand Canyon without any chance of hiking out and the feeling that you have when you have a pathway toward the top.