The incidence of sexual dysfuntion in patients treated for depression is a major cause of discontinuance of antidepressants. Depression is also a notorious cause for decreased libido and erectile dysfunction as well as delayed orgasm so the taking of antidepressants only adds to the confusion on this subject. The SSRI's are reported to be more problematic than other antidepressants such as Buproprion (Wellbutrin). In fact Wellbutrin is marketed to consumers as an antidepressant that does not cause sexual sideeffects. Any research in the area of sexual behaviors is subject to the confusing social influences that typically color research results due to the reluctance to discuss these sensitive subjects.
One study in 2000 looked at the usage of either Amantadine (Symmetrel) or Buspirone (Buspar) in women complaining of sexual dysfunction associated to treatment of their depression with Fluoxetine. They found that:
"At baseline, pleasure and lubrication were rated as moderately impaired, while sexual interest and orgasm were more severely impaired. There was a modest imbalance between groups in initial ratings of interest/desire, pleasure, and overall function. Women in the buspirone and placebo groups rated these items as slightly more impaired than did women in the amantadine group. Overall sexual function improved significantly in each group, and the magnitude of mean improvement was similar for all three treatments. Most individual items showed a similar degree of improvement, however discomfort was not prominent at baseline and did not increase appreciably during the study. The degree of improvement from baseline on individual items was generally in the range of 20%–50%. There were no statistically significant differences between treatments and no statistically significant treatment-by-center interactions for any diary measure of change from baseline. The groups were not significantly different from one another at baseline or endpoint with respect to mean frequency of sexual activity, and there was no significant change in frequency of sexual activity during the course of the study within any group".
Why this study used these drugs is curious when one considers that Bupropion or even Testosterone have been shown to aide in sexual dysfunction in women. It would have been more interesting to explore these drugs instead of the study's choice of Buspirone and Amantadine.
Conversely in a later study in depressed men with erectile dysfunction not associated to SSRI treatment a group of researchers from Columbia Presbyterian Hospital in New York City have contributed to this discussion in a study finished in 2001.
The authors discuss the following facts about sexual dysfunction in middle aged men (avg age 56YO) and its comorbidity with depression ""middle-aged and elderly men, depression and erectile dysfunction are common and frequently comorbid. The relationship between depression and erectile dysfunction appears to be bidirectional: the presence of or alteration in one of these conditions may be the cause, consequence, or modifier of the other. For example, in depressed men, erectile dysfunction may be a symptom of depression or a treatment-emergent side effect of antidepressant medication . Alternatively, men with erectile dysfunction may develop a "secondary" depression as a reaction to the biopsychosocial stress commonly associated with loss of sexual functioning. Accumulating data support a strong link between erectile dysfunction and depression".
These chicken or egg issues here are partly answered by the treatment of this research cohort with Sildenafil Citrate (Viagra)
The Columbia group found that "Overall, treatment with sildenafil in depressed men with erectile dysfunction led to marked improvement in erectile function. Furthermore, subjects classified as treatment responders, regardless of treatment received, showed a clinically significant improvement in depressive symptoms and quality-of-life measures compared with subjects whose erectile dysfunction did not respond to treatment. Indeed, the magnitude of improvement observed in treatment-responsive subjects in this trial was comparable to that commonly observed in clinical trials of either drug or nondrug interventions for major depressive disorder. However, these results should not be interpreted to mean that sildenafil can be used as a primary treatment for depression."
These findings are striking when you consider that significant levels of depression with comorbidity of Erectile Dysfunction has been adequately treated by Viagra. The authors discuss their opinions as to these startling findings:
"Several explanations can be offered for the strong association observed between improvement in erectile dysfunction and related improvements in mood and quality of life. First, it is possible that sildenafil itself has direct mood-enhancing properties. This is highly unlikely, since the drug has no known central effects and was administered relatively infrequently. Second, it is possible that erectile dysfunction was a symptom of depression and that spontaneous depressive remission led to a positive erectile dysfunction response in some men. If true, this would only be detectable in the placebo group. However, the 14% placebo response for erectile dysfunction—even smaller than is usual in erectile dysfunction trials—would have been expected to be much higher if this were a common pathway. Finally, it is possible that nonresponse to erectile dysfunction treatment is the "active" agent in these relations as a marker of poor prognosis for depression. Indeed, erectile dysfunction appears to be a sentinel for subclinical cardiovascular disease, and erectile dysfunction nonresponse may be a marker of atherosclerotic severity. In depressed men, atherosclerotic disease may have a negative impact on major depressive disorder prognosis. In this context, it would be informative to evaluate the efficacy of conventional antidepressants in subjects who do not respond to erectile dysfunction treatment".
These studies highlight the complex nature of attempting to treat these sexual dysfunctions in depression in both men and women. On a clinical basis patient's suffer from a rock and a hard place scenario when it comes to addressing this sexual sideeffect issue due to SSRI's and the clinician is also conflicted as to proper treatment when a depressed patient presents with comorbid Erectile Dysfunction or a patient taking SSRI's complains of sexual dysfunction.
Clearly more research dollars need to be spent addressing this patient well being issue.