Lacking libido? Are antidepressants to blame?

by Heather S. Oliff, Ph.D.

Men at their sexual prime who take antidepressant medication are commonly faced with the embarrassment of loss of libido and erectile difficulties. These side effects may be so upsetting that they choose to stop taking their antidepressant medication. The result could be deadly.

In the general male population, 16% of all men have a decreased libido and 6%-10% have erectile difficulties. These percentages increase dramatically in men as they age and in men with untreated high blood pressure or untreated major depression. When antidepressant medication is used to treat depression, it causes sexual dysfunction in at least 30%-60% of the men and women who take it.

Your sexual response consists of four phases:

Sexual desire (libido) is dependent on hormonal factors and mental stimuli involving all your senses: touch, sight, taste, smell, and sound.

Sexual excitement or arousal is characterized by penile erection and vaginal lubrication. These are the result of an increase in blood flow to the area and an alteration in your brain chemicals.

Orgasm is the climax of sexual pleasure and is in response to hormones and brain chemicals.

Resolution involves the release of sexual tension; you know it better as "afterglow."

Brain chemicals control your sexual response, so any drugs or conditions that alter your brain chemistry can alter your sexual response. Dopamine is a type of brain chemical known as a neurotransmitter. Dopamine is very important for pleasure and reward, and an increase in dopamine activity may enhance the sexual response. Conversely, blocking dopamine may compromise the response.

Serotonin is a neurotransmitter present in significant quantities in areas of the brain responsible for feelings and emotion. Low serotonin levels can lead to depression and other conditions. The idea behind widely prescribed medications such as fluoxetine (Prozac), paroxetine (Paxil), and sertraline (Zoloft) is to keep levels of serotonin circulating longer by preventing its uptake and breakdown. But at the same time that these drugs are increasing serotonin activity and relieving depression, sexual response may be diminished.

Sexual function is an important component for quality of life, and is often affected by antidepressant treatment. In fact, over 50% of the men who take antidepressant medications such as Prozac and Zoloft experience sexual dysfunction. Many men are embarrassed and don't tell their doctors, but this is a mistake. You should report changes in sexual functioning to your doctor because he or she can help treat the problem. It is important that you do not terminate your medication.

Sexual dysfunction may not be a huge issue for patients receiving short-term antidepressant treatment. However, inadequate sexual functioning can offset the antidepressive benefits of long-term treatment. Sexual difficulties could theoretically cause patients to stop treatment and relapse into a deep depression.

There are numerous treatment options if your medication does cause sexual dysfunction. They include decreasing the dosage, taking drug 'holidays', adding another drug to counteract the problem, or switching to another drug. However, all of these changes should be prescribed and supervised by a physician. Unfortunately, none of these options have been successful in treating antidepressant-induced sexual dysfunction in all individuals.

There are some antidepressant medications that provide short and long-term medical benefits that do not have sexual side effects. These include Remeron (mirtazapine), Wellbutrin or Zyban (bupropion), and Serzone (nefazodone).

The use of ginkgo biloba for the treatment of antidepressant-induced sexual dysfunction was discovered by purely by chance. A 65-year old man was taking an antidepressant drug, which increased his serotonin levels. As a result, he experienced a loss of libido and erectile difficulties. While on vacation, he met numerous senior citizens that were taking ginkgo biloba for memory enhancement. After consulting with his doctor, the man began taking ginkgo biloba. To his delight, after four weeks of taking ginkgo, his libido and erections improved. While still taking the antidepressant medication he stopped taking the ginkgo, and his sexual problems returned. His sexual problems diminished when he resumed taking the ginkgo along with the antidepressant medication.

 For a drug effect to be real it must occur in more than just one person. To raise the ante, so to speak, Drs. Alan J. Cohen and Barbara Bartlick conducted a clinical trial that included 63 men and women taking antidepressant medication and suffering from antidepressant-related sexual side effects. The results were published in the Journal of Sex and Marital Therapy. The participants were given up to 120 milligrams of ginkgo biloba extract twice a day along with their regular antidepressant medication. Sexual dysfunction was tested before and after four weeks of ginkgo treatment.

In 84% of the patients, ginkgo alleviated antidepressant-induced sexual dysfunction. The patients reported an improvement of all four phases of the sexual response cycle: desire, excitement (erection and lubrication), orgasm, and resolution (afterglow). Of the patients that experienced an improvement, all were satisfied with the results and requested to continue taking ginkgo. No adverse side effects were reported, indicating that ginkgo is compatible with antidepressant medications.

In this study, everyone received ginkgo. Therefore, we don't know whether the improvement on sexual performance was a 'placebo effect'?whereby everyone thinks there is a benefit, but in reality there is no change?or a real finding. To confirm the validity of these findings, another clinical trial is needed in which one group receives a placebo and a second group receives the gingko. This way, the effects of the two treatments can be statistically compared.

There is a common misconception that herbal remedies are safe because they are natural. This is not true. Herbal remedies can produce adverse drug reactions similar to typically prescribed drugs. Any adverse drug reactions to an herbal remedy, such as ginkgo, should be reported to your health professional.

Side effects associated with ginkgo include stomach and intestinal upset, headache, allergic skin reactions, and potential for increased bruising. The authors of the study caution that if you are at risk for hemorrhage or take blood thinners, you should not use ginkgo. The American Herbal Products Association states that ginkgo may increase the activity of monoamine oxidase (MAO) inhibiting drugs, such as Nardil, Marpan, Eldepryl, and a number of antituberculosis drugs. If you take an MAO-inhibitor, consult your health professional before taking ginkgo.

For more on herb-drug interactions see, "When Medicine and Herbs Don't Mix."