Lifting the Veil of Depression

May 29, 2008— -- According to the National Institute of Mental Health, more than 21 million Americans suffer from some kind of depressive disorder. For about 4 million of the most severe cases, no treatment can help. But there is a promising experimental therapy now in clinical trials that, in essence, "rewires" the brain. It is most definitely medicine on the cutting edge.

Click here for deep brain stimulation clinical trials for treatment resistant depression.

Click here for clinical trials for severe depression.

Diane Hire of Norwalk, Ohio, is 54 years old. For the past 20 years, she has lived with severe, unrelenting depression.

"You felt like a dead person walking. There was just nothing left in me," Hire told ABC News. "I had no emotion left. I had no energy left. I had nothing. I was an empty shell of a person."

She was prescribed one anti-depressant after another, as well as psychotherapy. Nothing worked. She tried to commit suicide three times.

"It was unbearable. It was just unbearable." she said. "You start to feel that your friends and family would be better off without you." Hire reasoned, "There's just not anything that's going to change. So why live like this?"

Finally, her psychiatrist suggested a radically different, experimental treatment: deep brain stimulation, the same procedure that's been used safely for two decades to calm the tremors of Parkinson's disease and is now being tested on severe depression.

Using a brain model, Dr. Ali Rezai, a neurosurgeon at the Cleveland Clinic and lead investigator of the clinical trial for this treatment, showed ABC News how deep brain stimulation works.

"We slowly advance this probe into the brain," he said, "and it goes to the precise location where there's abnormal activity going on resulting in depression. ... [Then] we activate it by inserting tiny electrical pulses."

The pulses are mild enough so that the patient does not feel anything, but they're powerful enough to change a patient's mood.

With Hire's head immobilized in a brace and electrodes deep inside her brain, doctors start adding those electrical "pulses" to her brain. Diane feels the effects immediately.

"I'm starting to smile. I'm so happy," she said.

Minutes later, doctors increase the electrical intensity, and her mood improves further. Hire smiles, saying, "I feel good." She tells the surgeons she cannot remember the last time she felt like this.