Sex difference in antidepressant response
In the largest analysis of gender differences in response to antidepressant treatment, researchers found that women are more likely to benefit from treatment with common antidepressants than are men.
The study, published online this week in the Journal of Psychiatric Research, found that women taking Celexa, a commonly prescribed antidepressant also available as a generic called citalopram, were more likely than men to get relief, according to a University of Michigan Health Center press release. In the study, 2,876 depressed patients, about half of them men and half women, were treated with the drug for 12 to 14 weeks.
When screened before the trial, the women had more severe depression symptoms, earlier onset of depression, were more likely to have a family history of depression or previous suicide attempts. Despite the greater severity of the disease, women were 33% more likely to experience a full remission from their depression at the end of the trial period.
"Other studies have suggested that there are differences between men and women in response to different antidepressants, but the evidence has been conflicting," Dr. Elizabeth Young said in the release. She is professor of psychiatry at the University of Michigan and lead author of the study. "This study is large enough, and we were able to control for enough complicating factors, that we feel confident there is a true difference."
All of the study participants, ages 18 to 75, had been depressed for years, with an average length of depression of 12 years.
Celexa, like Prozac, Zoloft, Luvox and Paxil, is a selective serotonin reuptake inhibitor, primarily affecting one neurotransmitter, serotonin. Earlier studies of an older generation of antidepressants called tricyclics showed gender differences. In those studies, women responded more slowly to tricyclics and were less likely than men to get relief from depression. This is the largest and most thorough study showing a gender difference with the new class of drugs.
The study itself didn't look at hormonal differences in men and women that might account for the difference. But animal studies have shown that estrogen, the primary female sex hormone, affects brain systems involved in the activity of serotonin.
Still, the drugs helped some men. About a quarter of men in the study achieved full remission of their depression. It's typical for depressed patients to try several medications before finding one that works well for them, often in combination with talk therapy.
-- Susan Brink