Antidepressants may do more than improve the symptoms of depression. According to a new study, these drugs may actually protect the brain in individuals who have repeated bouts of major depression.
Previously, investigators have reported that the size of the hippocampus, the brain area involved in learning and memory, is smaller in people who have experienced depression. This may be why patients with depression have trouble concentrating and paying attention, Dr. Yvette I. Sheline told Reuters Health.
Sheline, of the Washington University School of Medicine in St. Louis, and her colleagues speculated that the length of time a person is treated with antidepressants may affect the loss of hippocampal volume.
To investigate, the researchers interviewed 38 women with a history of depression. They used magnetic resonance imaging (MRI) to compare the size of the hippocampus in the depressed women with those of women who had never been depressed.
On average, the hippocampus was 10% smaller in the depressed subjects.
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However, when they looked at the effect of antidepressants, they found that the hippocampus had not shrunk as much in patients who had been on antidepressants for a longer period of time.
Some of the subjects had never gone into full remission from their depression, Sheline told Reuters Health. But even among these subjects, she said, "there does seem to be a protective effect."
Psychiatrists now recommend that patients who have multiple episodes of depression remain on antidepressants for the rest of their life, because they are less likely to relapse, Sheline noted. However, many patients don't want to take antidepressants or don't want to stay on them long enough. Her group's findings suggest that, not only do patients feel better when taking the drugs, their physical brain is actually better off.
A lot of previous research in animals has shown that antidepressants do not harm the brain or the neurons, but that instead, there is a clear-cut benefit, Sheline noted. Her team's study now shows the same is true for humans.
Her group now plans to invite the same women back for repeat MRI, in hopes of determining if the hippocampus shrinks more as time goes by, and if antidepressants "improve the situation."
SOURCE: American Journal of Psychiatry, August 2003.