I know that DBS for depression puts the electrodes in a different spot in 
brain than the subthalmic nucleus, as for Parkinson's. Although I would 
consider myself as "anxious" rather than "depressed" before  DBS, since then 
my ocular migraines stopped and I am never depressed although I think I 
should be as my life is not so great.  Does anyone else who has had DBS for 
Parkinson's think DBS has affected their mood in a positive way?

Ray

Psychiatr News June 20, 2008
Volume 43, Number 12, page 20
© 2008 American Psychiatric Association

Deep Brain Stimulation Studied for Depression
Jun Yan
As an option for patients who don't respond to other interventions, deep 
brain stimulation is drawing considerable interest. By blocking abnormal 
electrical signals in the brain, researchers hope to "silence" severe 
depression.
Although deep brain stimulation (DBS) is currently approved by the Food and 
Drug Administration for Parkinson's disease treatment, researchers are also 
exploring its use in patients with treatment-resistant depression, with some 
promising discoveries.
Helen Mayberg, M.D., describes the dramatic effect of deep brain stimulation 
on patients with treatment-resistant depression.
At a lecture at APA's 2008 annual meeting last month, Helen Mayberg, M.D., a 
professor of psychiatry and neurology at Emory University, presented 
exciting evidence that not only offers hope to those whose depression has 
not been relieved with conventional treatments but also brings into focus 
the pathways in the brain that are directly involved in depression.
Clinical research has repeatedly shown that about one-third of patients with 
depression have little or no response to antidepressant treatment. Although 
electroconvulsive therapy (ECT) is effective for a proportion of patients 
who have inadequate or no response to pharmacotherapy, many remain resistant 
to the treatment.
Enter DBS, a surgical procedure that directly modulates certain neural 
wirings with constant electricity. Two electrodes are planted bilaterally at 
specific spots in the brain where they release continuous, low-voltage 
electrical shocks directly to the neurons around their tips. The electrical 
impulses suppress the physiological electrical currents transmitted among 
neurons and in effect "wipe out" the signal transmission in certain neural 
circuits.
The electrical current is supplied by a small battery implanted under the 
skin near the patient's chest.
The surgery to implant the device can be performed under local anesthesia, 
which allows the patient to remain conscious throughout the procedure. 
Because the precise placement of the electrode is critical, the operation is 
guided by brain-imaging tools such as magnetic resonance imaging (MRI).
The risks and side effects of electrode brain implantation are similar to 
those for the procedure in Parkinson's disease.
One advantage of the procedure is its reversibility. In addition, the 
voltage and frequency of the electric impulses delivered can be adjusted by 
the treating physician according to patient response.
Zapping the Mysterious Area 25
More than one brain circuitry is being explored as the target for depression 
treatment. In her presentation, Mayberg said her research focuses on 
stimulating the circuitry in the subgenual cingulate (sCg) area, also known 
as Brodmann area 25.
Although scientists are only scratching the surface of the neurological 
mechanisms that contribute to depression's pathology, the mysterious area 25 
inside the anterior cingulate cortex has attracted much attention. It has 
been shown to be overactive in patients with depression or in healthy people 
experiencing artificially induced sad feelings. Antidepressants seem to 
suppress this overactivity.
This area of white matter sits on the crossroads of an extensive web of 
important pathways. It is heavily involved in cortisol regulation and stress 
response, sleep modulation, serotonin modulation and trafficking, emotion 
regulation in the limbic system, and motivation and drive.
"It's at the hub of all the tracks that can wreak havoc on all the core 
systems that are affected by major depression," Mayberg said.
The premise of DBS is similar to that for ECT, as both approaches use 
externally applied electricity to alter the brain's own electrical 
transmission. Mayberg called ECT a matter of "rebooting the system," while 
DBS continuously tinkers with a specific piece of neural wiring.
Patients Report Immediate "Lift"
In a pilot study conducted at the University of Toronto in 2002, six 
patients who had prolonged, debilitating depression and experienced no 
relief after taking at least four different antidepressants (five of the 
patients had failed ECT as well) received MRI-guided surgeries for DBS. Two 
electrodes were implanted through two small holes in the skull into the 
targeted areas. Patients were kept awake during the operation. To monitor 
for side effects, the researchers instructed them to report anything they 
might feel.
The effect was dramatic. "In the first operation, as we turned up the 
[electric] current slowly from zero to four volts, the patient suddenly 
said, 'Did you do something? I have a sudden sense of calmness," explained 
Mayberg. "The phenomenon was seen not in every patient but [was] quite 
common."
Unlike transcranial stimulation, the electric stimulation in the brain does 
not create a direct sensation. The immediate sense of calm, quiet, relief, 
and lightness reported by some study subjects occurred only when a specific 
spot was stimulated with a particular dose of electricity. These spontaneous 
reports of a "weight being lifted" were followed by patients' increased 
awareness, interest, attention, speech, and engagement with others in the 
room about 10 to 15 seconds later. They also mentioned changes in visual 
perception. "Patients said they thought the light in the room had been 
turned up, and the colors seemed more saturated," Mayberg said.
Preliminary Response Gives Hope
The acute effects in the operating room are not, however, predictive of 
long-term efficacy in patients getting DBS, Mayberg reported. But with 
chronic stimulation in their brain a majority of the severely depressed 
patients got significantly better. Four of the six patients in the Toronto 
study achieved response (defined as a 50 percent reduction in scores on the 
Hamilton Rating Scale for Depression) by the end of six months after the 
implantation, and the response continued for a year. The study results were 
published in the March 3, 2005, Neuron.
The four patients who responded in the 2002 pilot study continued with the 
treatment and, after almost five years, remained well, Mayberg said. The 
study has since been expanded to 20 patients, and researchers have seen a 
comparable response rate and a consistent pattern: patients who responded 
early stayed well. The results of this new study will be published soon.
DBS alone will not cure those who have suffered from severe and prolonged 
depression for years. "If you've been sick for that long, you need 
behavioral rehabilitation," Mayberg emphasized. "You cannot just put the 
stimulators in and send people on their way. This requires a highly 
coordinated collaboration between neurosurgeons and psychiatrists."
The procedure carries risks inherent in any brain surgery, such as 
infection, hemorrhage, and seizure. The subcutaneously implanted battery and 
wires may pose risks for superficial infections. There has been no evidence 
of autonomic, motor, or overt mood changes observed in study participants so 
far, including in at least one person who had been receiving continuous 
stimulation for five years.
Mayberg cautioned that as promising as these data are, DBS is still 
experimental in relieving treatment-resistant depression. More trials must 
be conducted to clarify unanswered questions such as why certain patients 
still do not respond to the treatment, what long-term side effects may 
emerge, and what the safe and effective doses of electrical impulses should 
be. Researchers are also investigating the effect of DBS on depression in 
bipolar II patients. Other DBS studies are being conducted in New York, 
France, Argentina, Germany, and elsewhere.

Copyright © 2008 American Psychiatric Association. All rights reserved.

Rayilyn Brown
Director AZNPF
Arizona Chapter National Parkinson Foundation
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