Benjamin Greenberg, at Butler Hospital and Brown Medical School in Providence, R.I., is now studying DBS at this brain site for depression. In a pilot study, two patients had clinically significant responses and two others had “more inconsistent benefits,” Greenberg reports. Another team, led by Helen Mayberg, a neuroscientist formerly at the University of Toronto and now at Emory University, is targeting a section of the subgenual cingulate known as Brodmann area 25, which she found highlighted in brain-imaging studies among patients reporting profound sadness as well as in studies of various antidepressants. In the March 3, 2005, issue of Neuron, Mayberg published encouraging “proof of principle” results from six patients, with four patients showing a sustained remission of their depression well past one year with continued DBS treatment. An additional nine patients have undergone the procedure, and they appear to show a comparable rate of response.
“DBS has powerful effects on behavior,” Greenberg says, though he cautions that further testing will require carefully selected patients at specialty centers that maintain close, long-term contact between the patients and the psychiatric team.
These devices and their current uses are just the tip of the iceberg, says Columbia’s Lisanby. Yet despite the excitement generated by new approaches to brain stimulation, many experts caution that the rush to put them into practice should not outstrip the science. Clearly, at least for now, these devices have limited effectiveness. Yet the same is true for ECT and psychotropic drugs, and even modest results can make a major difference in the real world, helping some people function at work or at home, or making them more responsive to talk therapy.
The research involving brain stimulation is also helping change the understanding of depression as a medical disease that arises from abnormalities in the brain. The new devices seem to be taking us closer to determining what those abnormalities are—and that, in turn, could lead to still other tools and strategies for brightening depression’s darkness.
 Dossier
1. Magnetism on the Brain: Researchers Probe Transcranial Magnetic Stimulation, by Tracy Hampton. Medical News & Perspectives; JAMA, April 13, 2005. An overview of the history of transcranial magnetic stimulation and its therapeutic potential for depression and other conditions.
2. Deep Brain Stimulation for Treatment-Resistant Depression, by Helen S. Mayberg et al., Neuron, March 3, 2005. Report of findings that the subgenual cingulate region is metabolically overactive in treatment-resistant depression and that DBS applied to this region effected sustained remission in four of six patients.
3. VNS and depression: current status and future directions, by Sally P. Walsh and Mitchel A. Kling, Expert Review of Medical Devices, September 2004. A summary of research findings and the questions that still need to be addressed.
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