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TUESDAY, May 6 (HealthDay News) -- Recently developed types of imaging techniques enable researchers to map brain circuits and chemical systems believed to play a role in depression, bipolar disorder and other mood disorders, and may help lead to improved treatments.
Information about these techniques was expected to be presented Tuesday during a news conference by researchers taking part in U.S. National Institute of Mental Health symposiums at the American Psychiatric Association annual meeting, in Washington, D.C.
"These studies contribute new information about how the brain malfunctions in depression and bipolar disorder, what goes wrong with brain chemicals, and where in the brain the problems arise," Dr. Ellen Leibenluft, of the NIMH, said in a prepared statement. "We find that the brain systems involved and the exact nature of the difficulties differs among patients, even when those patients have similar symptoms. Eventually, data like these will allow us to develop more individualized and targeted treatments for depression."
In one study, University of Michigan researchers using molecular imaging with positron emission tomography (PET) found that patients with untreated major depression had an overall reduction in the concentration of serotonin 1A receptors in the hippocampus, a brain region that helps regulate stress.
"The reductions in these receptors were correlated with the functional impairment of the patients in work and with their families, with greater impairment being associated with lower receptor concentrations in this region," study author Dr. Jon-Kar Zubieta said in a prepared statement.
The patients responded to treatment with citalopram.
In another study, Zubieta and colleagues found that people with untreated major depression had reduced concentrations of "mu" opioid receptors in the thalamus, an area of the brain involved in the regulation of emotions. The mu receptors play a key role in regulating mood and triggering brain reward systems. A reduction in the receptors was associated with greater concentrations of stress hormones.
