June 17, 2003 — Depressiondoes cause changes in the brain — physical changes that can be viewed with the newest brain imaging devices. It’s more evidence that a chemical imbalance has occurred, and that depression medication can help.

Using what’s known as PET imaging — positron emission tomography — researchers have seen brain changes in people who are taking depression medication.

Depression medication controls depression by increasing amounts of different brain chemicals like serotonin, norepinephrine, and dopamine.

PET imaging shows the effects of these depression medications on different areas of the brain, writes lead researcher J. Douglas Bremner, MD, a psychiatry professor with Emory University School of Medicine in Atlanta.

This imaging technique also allows researchers to see brain activity when things seem to be going wrong.

To more fully understand this process, Bremner conducted a small study of 18 patients. For three days, half the patients took a drug (known as ATMP) that reduced levels of norepinephrine and dopamine in the brain — and simulated the return of depressive symptoms in 11 patients. The other patients got a placebo drug.

When researchers viewed the patients’ brains in a PET scan, they saw differences in brain activity between the two groups.

Patients who had a return of depression symptoms from the ATMP drug had less activity in a number of brain regions.

The study documents brain changes during depression. It also shows that a common abnormality in these areas of the brain may put people at risk for a recurrence of depression, Bremner writes.

In addition, differences in brain activity as seen by PET scans could predict who is likely to have a recurrence of depression after taking depression medication, according to the researchers.

SOURCE: The Journal of the American Medical Association, June 18, 2003.