Saint Louis University, working in collaboration with Washington University School of Medicine, conducted a pilot study of brain scans of a small group of depressed patients who received vagal nerve stimulation after failing other therapies.

Positron emission tomography (PET) scans showed significant changes in brain activity starting three months after vagal nerve stimulation treatment began. These changes continued to evolve over the course of the next 21 months.

These changes in brain scans appear to "roughly parallel" the significantly delayed effects that psychiatrists observed in improvement in mood.

"The effects come after a significant period of treatment time," said Charles Conway, M.D., an assistant professor of psychiatry at Saint Louis University School of Medicine and the lead investigator of a vagal nerve stimulation research project conducted between 2000 and 2004.

Psychiatrists are not used to such a long time lag before a treatment begins to be effective, he added.

"This is very different from the delays we see with existing treatments for depression, including pharmacotherapy and electroconvulsive therapy (ECT)," Dr. Conway said. "The biggest changes in the brain that we're noting occur between 12 and 24 months after patients began receiving vagal nerve stimulation. In psychiatry, we're used to seeing results after six to 12 weeks."

Dr. Conway cautioned the findings are preliminary and need replication.

"But they suggest that in this type of therapy, the brain takes a relatively long time to change, perhaps as long as a year or more. In this sense, vagal nerve stimulation may represent a paradigm shift in the way we view d
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Contact: Nancy Solomon
solomonn@slu.edu
314-977-8017
Saint Louis University
25-May-2006