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Sex Difference in Response to SSRIs

A recent study suggests that women respond better than men to a commonly used antidepressant medicine, citalopram. The study was designed to compare a large sample of patients in both primary and speciality psychiatric care settings. Although the women had more severe disease at baseline, they responded better to citalopram treatment and experienced more remissions than did the men.

EscitalopramCitalopram belongs to the class of drugs known as selective serotonin reuptake inhibitors (SSRIs). Low serotonin levels are believed to contribute to both mild and severe cases of depression; SSRIs increase serotonin levels at the synapse by blocking reuptake into the presynaptic cell. Citalopram is a racemic mixture; the active S-enantiomer is known as escitalopram.

Although men also benefitted from treatment with citalopram, the authors suggest that the greater response in women may be attributable to sex-specific biological differences, particularly in serotonergic systems. Previous studies have shown that women have lower levels of the serotonin reuptake transporter than men as well as higher levels of the most common serotonin receptor and that there are important differences in the way that men and women react to reductions in serotonin function.