Brain TMS aka Transcranial Magnetic Stimulation May Trump Drugs For Severe Depression
Eric Nakagawa stashed this in health
I love the concept of magnets as medicine:
Drugs are the most common psychiatric treatment for depression. But about 40 percent of people fail to respond to this first-line of antidepressants. What to do? The answer to date has often been more and different drugs.
But transcranial magnetic stimulation (TMS), a technique that can revive activity in neurons in the brain's prefrontal cortex using an electromagnet, has been receiving more attention as a possible treatment for these stubborn cases of depression. In 2008, the FDA approved TMS for this purpose. Data since that point has been promising, but questions remain: How does it compare to antidepressant drugs? Is it cost-effective?
Research presented today (May 6) at the American Psychiatric Association's annual meeting in New York suggests that the technique is perhaps better than previously thought. In the study, the researchers compared two groups: those who had received TMS after failing to respond to drugs, and those who were given new antidepressants after not getting better on prior meds. The finding: 53 percent of those receiving TMS had no or mild depression after six weeks of treatment, compared with 38 percent taking a new or augmented type of antidepressant.
The study also looked at the economics. It found that TMS therapy would cost about $10,000 per patient per year, which is considered quite affordable.
In TMS therapy, an electromagnet is applied to the left side of the forehead. This induces currents in neurons in the left prefrontal cortex--where brain imaging studies have shown a deficit in activity in depressed patients. It is thought that this can induce activity and blood flow to this area, but also causes changes in areas deeper in the brain (responsible for mood regulation) to which neurons in the cortex connect. Side effects of TMS tend to be mild, especially compared to antidepressants, and the most common complaint is a mild headache, Simpson said.
Exactly how TMS works is a mystery, Dr. Janicak said. But the same can be said of antidepressants, he added.
Wait, no one knows how antidepressants work???
Magnetic pulses from a device applied to the head appear to "reset" the brains of depressed patients, according to a new study from the United Kingdom.
The circuitry in a part of the right prefrontal cortex is known to be too active in depressed patients, causing excessive rumination and self absorption and impaired attention. When the TMS was applied to healthy subjects in this study, the activity in that region slowed.
"We found that one session of TMS modifies the connectivity of large-scale brain networks, particularly the right anterior insula, which is a key area in depression," lead scientist Sarina Iwabuchi, told the European College of Neuropsychology at a conference in Amsterdam this week.
This was the first time an MRI was used to guide the TMS impulses and, at the same, time measure subtle changes in brain circuit activity. In addition, the researchers used magnetic resonance spectroscopy to analyze subjects' brain chemistry.
"We also found that TMS alters concentrations of neurotransmitters.Iwabuchi said, "which are considered important for the development of depression," and which are the targets of most current antidepressant medications.
Transcranial Magnetic Stimulation is the use of an electromagnetic coil to deliver small, powerful bursts of energy to targeted areas known to be involved in mood regulation. It is a painless, non-invasive treatment than involves no drugs, no IVs, or any other kind of sedation, and whose chief possible side effect is a headache. (The Food and Drug Administration approved limited use of TMS in 2008 for the treatment of depression.)
The importance of a new tool to treat depression, say experts, cannot be understated. It's been more than 30 years since a truly new medication has come on the market and for those with intractable depression, TMS could be a much-needed alternative. Previously, when multiple courses of drugs have not helped, electroconvulsive therapy was often a patient's only option. Formerly known as shock treatment, ECT has been around for decades, requires anesthesia, and the electricity delivered to the brain is much more direct and much less targeted than with TMS. Scientists also have little understanding about why electroconvulsive therapy works, when it does.