Every Saturday the CSPH highlights news or recent research in the field of human sexuality. This week we’re discussing a 2009 study that searched for genetic and clinical predictors of sexual dysfunction in patients being treated pharmacologically for depression.
The occurrence of sexual dysfunction is one of the reasons that patients treated with selective serotonin reuptake inhibitors (SSRIs) stop taking their medication. The exact reasons why SSRI exposure causes problems with sexual functioning are not clearly known. This study, entitled “Genetic and Clinical Predictors of Sexual Dysfunction in Citalopram-Treated Depressed Patients,” was done by researchers Roy Perlis, Gonzalo Laje, Jordan Smoller, Maurizio Fava, John Rush and Francis McMahon of Massachusetts General Hospital, the National Institute of Mental Health, and the University of Texas Southwestern Medical Center in order to understand the specific mechanisms related to sexual functioning affected by SSRIs.
The researchers collected clinical data from a Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study, a treatment effectiveness trial in outpatients with non-psychotic major depressive disorder (MDD). Self-reports of erectile dysfunction, decreased libido, or difficulty achieving orgasm were gathered from Caucasian subjects treated openly with citalopram for up to 14 weeks. Citalopram is a SSRI used to treat depression that works by increasing serotonin, a natural substance in the brain that helps maintain mental balance. Of the 1,473 participants, 799 (54%) reported decreased libido, and 525 (36%) reported difficulty achieving orgasm. Of the 574 male participants, 211 (37%) reported erectile dysfunction. The researchers also examined genetic polymorphisms for association with erectile dysfunction, difficulty reaching orgasm, and decreased libido during citalopram treatment. The researchers’ final analysis suggests possible glutamatergic targets for the treatment of certain sexual dysfunctions during major depressive episodes.
One of the limitations of this study is the subject pool only included Caucasian men and women. The analysis also did not discuss the differences between male and female sexual functioning and if there was any data to support differences in the affects of SSRIs. Another limitation, discussed by the authors, is that no detailed and validated assessment of sexual function was used. Therefore, sensitivity to sexual symptoms and the ability to dissect individual components affected was limited. Related to this is the difficulty in determining the source of the sexual dysfunctions reported by the subjects. The researchers stated that in order to address this issue, they performed a series of follow-up analyses, but these methods are not completely explained in the research. While research has shown a strong correlation between anti-depressant medication and sexual dysfunction, it is relatively impossible to know whether the reported sexual dysfunctions are solely a result of the SSRI, a result of the clinical depression, a combination of both, or caused by other clinical factors or events in the individuals’ lives.
Please click here to read the entire study.