Depressed or healthy? How antidepressant alters brains differently

A new study has suggested that a commonly prescribed antidepressant may change brain structures in depressed and non-depressed individuals in very different ways.

The Wake Forest Baptist Medical Center study, conducted in nonhuman primates with brain structures and functions similar to those of humans, found that the antidepressant sertraline significantly increased the volume of one brain region in depressed subjects but decreased the volume of two brain areas in non-depressed subjects.

Lead author Carol A. Shively said that these observations are important for human health because Zoloft is widely prescribed for a number of disorders other than depression.

In humans, Shively said, volume differences in neural structures have been noted in depressed and non-depressed individuals, with the most commonly reported differences being smaller volumes of the cingulate cortex and hippocampus in depressed people.

One potential mechanism through which drugs such as Zoloft can be effective as antidepressants is by promoting neuron growth and connectivity in these brain regions.

Shively noted that the study's findings regarding the different effects of sertraline on brain-region volumes in depressed versus non-depressed subjects are compelling, but given the number of different disorders for which SSRIs are prescribed, the findings need to be investigated further in patient populations to see if these drugs produce similar effects in humans.

The study is published online in the journal Neuropharmacology.