Testosterone and Parkinson's disease
ATLANTA, GEORGIA. Many patients with Parkinson's disease (PD) also suffer from depression, anxiety, a
decreased energy level, sexual dysfunction, and an overall decline in their quality of life. In many cases
these conditions cannot be treated satisfactorily with normally prescribed medications.
Researchers at Emory University now report that these comorbid conditions, at least among men, could be
due to a testosterone deficiency. They describe five cases of elderly men with PD who were suffering from
depression, fatigue, decreased libido, and decreased work performance. All of them had lower than normal
testosterone levels. They were given testosterone replacement therapy (TRT) involving daily applications of
testosterone gel. One month later they were re-evaluated and all showed marked improvement in emotional
well-being, libido (sex drive), erectile dysfunction, mobility, and work performance. The researchers also
tested 68 other male PD patients for testosterone and found that 35 per cent of them had a deficiency (total
plasma level below 325 ng/dL [11.3 nmol/L]). This compares to an average incidence of 20 to 25 per cent
among males over the age of 60 years in the general population.
The researchers conclude that testosterone deficiency is more common among men with PD than among
men free of the disease and that the comorbid conditions (anxiety, depression, etc.) often accompanying PD
may respond favourably to testosterone replacement therapy.
Okun, Michael S., et al. Refractory Nonmotor symptoms in male patients with Parkinson disease due to
testosterone deficiency. Archives of Neurology, Vol. 59, May 2002, pp. 807-11
Editor's comment: The Emory researchers also found some indication that TRT may improve the
symptoms of PD itself, but concluded that the sample size was too small to say for sure. Clearly men with
PD should have their testosterone levels checked and adjusted with TRT if necessary.