New Drug-Free Depression Treatments
More than 14 million adult Americans experience a depressive disorder every year. This doesn't describe just feeling "down" -- the problem affects many aspects of a person's life, including sleep and eating patterns, and manifests itself in feelings of worthlessness and despair and an inability to focus or believe life will get better. However, most people go on to recover within 10 months, says psychiatrist John O'Reardon, MD, assistant professor of psychiatry at the University of Pennsylvania School of Medicine in Philadelphia. There is a substantial subgroup of depressed people, more than 25% of patients, according to Dr. O'Reardon, who are "treatment resistant." For this group, standard treatment of talk therapy and/or medication, sometimes even after many years, proves to be of no help or of short-term help only. Now the FDA has approved a new device that may turn at least some of these people around, helping them to become depression-free at last. The device is called the vagus nerve stimulator (VNS), which Dr. O'Reardon told me is a sort of pacemaker for the brain. The VNS was originally developed for epilepsy patients some 15 years ago, but when doctors observed the improved moods of these patients, they began to investigate its applicability to severe depression.
HOW VNS WORKS
Doctors surgically implant the one-ounce programmable device into the left chest wall, positioned to deliver electrical signals to the left vagus nerve, which is located in the neck along the side of the esophagus. A psychiatrist programs the device for appropriate pulse-generated stimulation of the nerve. It is actually on only about 10% of the time, but the VNS has been of significant benefit for many treatment-resistant patients. Albeit potentially skewed, data from the manufacturer (Cyberonics, Inc.) showed that 18% of VNS patients became depression free... 35% had reduced symptoms... and 57% had some benefit. Although the results sound good, they are not an overnight fix. Results can take as long as one year to be fully realized. On the upside: Side effects are generally minimal, with hoarseness or scratchy throat being the most common.
OTHER TOOLS ON THE HORIZON
Dr. O'Reardon reports that he and others are currently conducting clinical trials on yet another mechanical device for depression that is already in use in Canada. Called the transcranial magnetic stimulator (TMS), this is basically a magnet that a doctor puts on the patient's scalp to stimulate appropriate areas of the brain. Depression mainly affects two parts of the brain -- the prefrontal cortex, which is involved in concentration and drive, and the limbic system, which regulates mood and emotion. Depression causes the prefrontal cortex to shut down and the limbic system, which controls anxiety and hypersensitivity to stress, to become overactive. TMS allows doctors to activate the prefrontal cortex and slow down the limbic system, thereby creating balance that had been lost. In 20-minute sessions, TMS sends out pulses for 10 seconds every minute. Patients need 15 to 20 sessions over three to four weeks to start getting results, and there are virtually no side effects. Patients may need several sessions per month as maintenance, although there are no studies yet to establish this. Dr. O'Reardon reports that TMS may get approval for use in this country in another year. Dr. O'Reardon explains that the idea behind all treatment, including psychotherapy and medication, is to reactivate and balance these neurological systems. For patients whose depression is deeply entrenched, however, a mechanical device such as the VNS or TMS may be the answer because they directly affect the brain and are generally quite low in side effects.