A common antidepressant changes the brains of depressed and nondepressed people in different ways, a new study finds.
Sertraline, which is marketed as Zoloft, increased brain volume in one area in depressed people, the researchers found.
In nondepressed people, though, it decreased brain volume in the same area.
The areas are critical to learning, memory, spatial navigation, emotion and motivation.
Professor Carol A. Shively, who led the study, said:
“These observations are important for human health because Zoloft is widely prescribed for a number of disorders other than depression.”
The conclusions come from a study of monkeys, which have similar brain structures to humans.
A group of monkeys were fed the antidepressant for 18 months — equivalent to five years in humans.
They were compared with a placebo group.
Brain scans revealed the antidepressant increased brain volume in the anterior cingulate cortex.
In nondepressed patients, though, it decreased brain volume in the same area, as well as in the hippocampus.
Both areas are critical to learning, memory, spatial navigation, emotion and motivation.
It could be that antidepressants can be useful by promoting neuron growth in these critical areas.
Professor Shively said:
“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 research was published in the journal Neuropharmacology (Willard et al., 2015).
Shiny brain image from Shutterstock