I 've written several stories recently about depression, largely because new research shows that it is not only a growing public health problem, affecting at least 25 million Americans at some time in their lives, but also because 170 million prescriptions -- amazingly, more than for blood pressure medications -- are now filled annually for the treatment of depression. I'm not alone in my conviction that it is important to recognize that depression often relates to anxieties and fears that need to be resolved in order to feel better (see Daily Health News, January 27, 2009, for more on this topic). However, it's also evident that a significant number of patients -- 30% or more, according to some experts -- suffer what's known as "treatment-resistant depression," with symptoms so severe that psychotherapy, drug therapy and other standard modalities don't help and they find themselves virtually unable to work or leave the house. There are some new approaches that may offer relief to at least some sufferers.

According to Robert J. Hedaya, MD, DFAPA, clinical professor of psychiatry at the Georgetown University School of Medicine and founder of the Hedaya Clinic and National Center for Whole Psychiatry in Chevy Chase, Maryland, these new approaches represent welcome change. In his view, treatment approaches have thus far been too narrow and limited given that known causes of depression vary widely, from hormonal and nutritional deficiencies and immune dysfunction to infection, genetic susceptibility and dysfunction in the brain... not to mention stressors, such as loss or trauma and socio-economic factors, including poverty and isolation. It makes sense, then, that there would be a wide variety of outcomes for virtually any therapy, depending on the underlying causes for a particular individual.

Two new treatment approaches utilize different modalities to stimulate an underactive area of the brain, in the hope that doing so will reduce depressive symptoms when other therapies have not been helpful.

THE DRAW OF MAGNETIC TREATMENT

The FDA recently approved a new device, called The NeuroStar Transcranial Magnetic Stimulation (TMS) Therapy system, which delivers very strong, targeted magnetic impulses to a specific area of the brain. The theory is that people with severe depression don't have normal activity in certain parts of their brain -- these pulses are intended to generate activity there, somewhat like a jump start.

Treatment with TMS is very straightforward: The patient sits in a comfortable, reclining chair while a technician positions the magnet to a precise location over his/her head -- once in position, the device fires a rapid series of focused magnetic impulses into the brain. The treatment can be noisy, but doesn't involve any cutting or injection of substance into the brain, so in and of itself, it is not painful. However, some patients feel some discomfort on the scalp and others report a headache that may last for hours following treatment. Each treatment lasts 40 minutes, and it's typically administered daily for four to six weeks. In a study conducted by the manufacturer, 54% of the 43 patients with treatment-resistant depression who were tested experienced a 50% improvement after six weeks of treatment and 33% experienced full remission of symptoms.

Downsides? Not many beyond the possibility of headaches, really -- although the follow-up period noted in the FDA study only lasted six months, and as a new treatment, long-term efficacy is still being tracked. The FDA-approved therapy is so new that it isn't widely available, and the procedure (which can cost $5,000 to $10,000 or more over the course of treatment) currently isn't covered by insurance. For more information on where TMS might be available, check the Web site at www.NeuroStarTMS.com.

A STIMULATING IMPLANT

The second device, still in the experimental phases, uses a stronger and more focused electrical impulse. Known as deep brain stimulation (DBS), this technique works in a similar way as an implanted pacemaker that regulates heartbeat in a cardiac patient. With DBS, tiny electrical wires snaked into the brain deliver a continuous flow of electricity that stimulates a particular part of the brain (what's known as the "depression circuit"). This form of treatment has been used extensively for Parkinson's patients, where DBS to a different brain area brings relief from symptoms such as tremors and dystonia. When some of those patients also experienced a notable improvement in mood, it led to the thinking that DBS might be helpful for people suffering from treatment-resistant depression.

DBS results have thus far been encouraging -- 60% of patients in one recent study (20 patients total), conducted at University Health Network, had a positive response that was sustained for the year they were followed. Other studies have found the effect lasted as long as the device remained in place, and anecdotal evidence suggests that when the devices are removed or turned off, the depression eventually returns.

I spoke with Sidney Kennedy, MD, Psychiatrist-in-Chief at University Health Network in Canada, one of the researchers currently studying DBS. He described DBS implantation as a relatively minor procedure. Using MRI for guidance, fine wires are threaded into a precise region of the brain. As with a cardiac pacemaker, a battery-operated transmitter is put in the chest, near the collarbone. It is activated by a magnet and remains constantly "on," though it can be turned off or removed, if desired.

Downsides? This is still surgery -- small holes are drilled into the skull to allow the wires to be inserted, so it carries the usual list of associated risks: bleeding, infection, reactions to anesthesia, and so on. If the surgery is a success the ongoing risks seem to be minor, though long-term studies still need to be done. At present, several randomized controlled studies are underway. Dr. Kennedy estimated it will be several years before DBS is widely available.

WHAT IT MEANS FOR PEOPLE SEEKING TREATMENT

As Dr. Hedaya and Dr. Kennedy both point out, these treatments give doctors a few more tools to use for treatment-resistant depression, but they're far from mainstream and will never be used casually. If you're interested in learning more, talk to your doctor about whether or not TMS makes sense for you. Or, look for a clinical trial of DBS through the National Institutes of Health's clinical trials Web site, www.clinicaltrials.gov or at www.neurostartms.com.