Why and How Parkinson's Disease Affects Function

Many people with Parkinson’s disease experience problems with sexual function. Though numbers are hard to come by as there are very few controlled studies on this issue, it appears that about 68% of patients report some problems sexual activity, ranging from impaired performance to decreased desire for sex. When PD medications are added to the mix, however, an opposite pattern of problems may present themselves –- at least for a small number of persons with PD. Sexual desire returns but may be channeled into new and sometimes unhealthy directions.

Sources of Sexual Problems
They can be caused by several factors, including low dopamine levels in the brain, aging, decreased ability to move, medication types and dosages, autonomic nervous system (ANS) dysfunction, and emotional issues such as depression and anxiety.

Loss of normal dopamine levels in the brain may be a primary cause of decreased libido in some persons with PD. Because dopamine functions in the brain as a kind of "pleasure molecule" or "reward" mechanism, loss of dopamine may make it more difficult to experience orgasm or pleasure. A recent study has also found lower levels of testosterone in some men with PD.

Aging, too, can contribute to problems with sexual activity as it is associated with decreasing levels of sex hormones in both men and women.

Furthermore, PD can affect your ability to move around easily in and out of bed. Sometimes you can improve your mobility by asking your doctor to adjust your dosing schedule. Instead of taking your medications only in the morning and afternoon you can add a dose at night if your doctor thinks this is acceptable. Continuous-release forms of medication may also help to smooth out wearing off effects and enhance mobility when you really need it.

Nervous System Changes
Autonomic nervous system (ANS) dysfunction is common in PD and can affect sexual functioning. The ANS controls many of those bodily functions that need to happen automatically and outside of our voluntary control such as the heartbeat, blood pressure, blood flow changes to meet a challenge, some aspects of breathing and so forth.

The ANS supports several facets of sexual performance from erections in men to lubrication and pelvic thrusting in women to orgasm in both men and women. If the ANS is not working properly some aspects of sexual activity will be more difficult to experience.

Emotional and Mood Changes
Emotional problems associated with PD can also contribute to sexual dysfunction in PD. Depression and anxiety, for example, are common in Parkinson’s disease.

The good news here is that these common mood problems can usually be successfully treated with a combination of psychotherapy and medications. Once the emotional problems improve, even slightly, sexual activity does as well. But be careful and honest with your doctor. Some medications that are used to treat depression (such as citalopram, fluoxetine, fluvomine, paroxetine, and sertraline) sometimes have side effects in some people that result in reduced interest in sex. Why complicate your sexual life by taking medications that decrease sexual desire if you can avoid that option?

If your doctor agrees, try the anti-depressants that do not lower sexual desire before taking the ones that are known to lower sexual desire.