Presents updates on psychology and its relation to the brain as of May 1, 2000. Treatment of depression by vagus nerve stimulation; Awareness about obsessive compulsive disorder; Role of the mechanism called Notch signaling pathway in identifying information.
By May 1, 2000 - last reviewed on June 9, 2016published
There's hope for the near million Americans suffering from untreatable depression. Results of a recent pilot study suggest that electrical stimulation of a specific nerve may succeed in combatting the most devastating forms of the blues those that have resisted medications, psychotherapy and other treatments.
The vagus nerve passes from the brain through the neck and into the abdomen, delivering information to and from brain regions that control mood, sleep and other functions. Researchers at four different sites implanted a small pacemakerlike device in the chests of 30 patients, tunneled wires from the device to the vagus nerve in patients' necks, then set it to deliver a small electrical pulse at five-minute intervals. Vagus nerve stimulation (VNS) alleviated depression in 40% of subjects during the eight-week study and, better still, halved the symptoms of 57% within six months.
"Half better means that somebody who was only sleeping one or two hours a night is now getting a full night's rest," says study co-author Mark George, M.D., professor of psychiatry at the Medical University of South Carolina. "That is a big thing when you are starting so deep in the hole." In order to qualify for the study, patients had to have suffered from major depression for over two years and to have failed to respond to at least two rounds of antidepressants and at least six weeks of psychotherapy.
George believes that VNS triggers changes in the brain's neurotransmitter output, though exactly how this happens isn't yet certain. In the meantime, it's clear that the device will be an important new weapon for treating the blues.
In this age of MTV-inspired rapid-fire images and sound bites, we are bombarded with more information than we can handle. How do we separate the refrigerator's hum from the phone's ring?
Yale neurobiologist Nenad Sestan, M.D., has identified a mechanism, called the Notch signaling pathway, that may provide the answer. Here's how it works: Each neuron we have represents part of a memory or association. Neurons grow cordlike extensions called axons and dendrites, collectively called neurites, that attach to other neurons. The more connections a neuron has, the more it is fired, reinforcing the memory it represents. Sestan has found that neurons surreptitiously fight to win the brain's attention by triggering the Notch receptor on neighboring cells, impairing these cells' ability to extend neurites so they can't communicate as well with the brain.
Sestan isn't sure how neurons know which cells to deactivate. But considering how much information we tune out daily, they're doing a good job--notwithstanding that TV jingle stuck in your head.
Living with Obsession
If you suffer from obsessive compulsive disorder (OCD), an illness characterized by oddly repetitive behavior such as washing one's hands too frequently, this may be an opportune time to seek help.
One reason: Awareness of OCD is at an all-time high. "We've seen an increase in the number of people coming for treatment," says Sheila Woody, Ph.D., director of the Yale University psychological services clinic. The media may be partially responsible for educating the public about OCD, adds Stephen Josephson, Ph.D., clinical assistant professor at Cornell Medical School. "They are illustrating that there are available treatments." This means scientists can better study and treat it, something they're already striving to do: Yale just added group treatment for OCD to its psychological services; New York University recently announced the creation of a center devoted to the study of neurological disorders, including OCD; and University of Nebraska researchers are examining ways to combat the disorder in schools. To learn more, visit the Obsessive Compulsive Foundation at ocfoundation.org.