Women respond better than men to antidepressant

Women with major depression are more likely than men to achieve remission during treatment with citalopram, an antidepressant that belongs to a class of drugs called selective serotonin reuptake inhibitors (SSRI), according to findings from the STAR*D (Sequenced Treatment Alternatives to Relieve Depression) study.

Previous research on this topic has yielded contradictory results, Dr. Elizabeth A. Young and co-authors note in their report, published online by the Journal of Psychiatric Research. The STAR*D study, they say, is “the largest to address sex differences in depression treatment using a representative sample of treatment-seeking patients.”

The current analysis included 2,876 outpatients between 18 and 75 years old, 64 percent of whom were female. Citalopram was initiated at 20 milligrams per day and adjusted up to a maximum dose of 60 milligrams per day. The patients were treated for major depression for up to 14 weeks.

At the beginning of the study, the women had more severe depressive symptoms and more additional illnesses than men did. Women were also more likely than men to have a personal history of a suicide attempt and a family history of depression or substance abuse.

According to Young, of the University of Michigan in Ann Arbor, and her associates, the female patients were significantly more likely to achieve remission, at 29.4 percent vs 24.1 percent, respectively. Remission was defined as a score of 7 or less on the 17-item Hamilton Rating Scale for Depression.

Treatment response—defined as a reduction of at least 50 percent from the beginning of trial on a self-reported 16-item inventory of depression symptoms—also occurred more frequently among women than the men (48.5 percent vs 44.0 percent).

Side effects, maximum dose, and length of time on the drug, did not differ between the men and women, the authors report. “The elimination of these potential explanations for the sex differences found in this study increases the likelihood that the explanation is a differential biological response to citalopram in women.”

The researchers suggest that the better treatment response among women is related to “the role of estrogen on serotonergic systems,” as well as cognitive and psychological factors that differ between men and women.

SOURCE: Journal of Psychiatric Research, August 29, 2008.