Men with low testosterone levels have much higher rates of depression and depressive symptoms than those of the general population, according to new research by George Washington University.

The findings, published online in the Journal of Sexual Medicine, are based on assessments of 200 adult men, aged 20-77, undergoing treatment for borderline testosterone levels — between 200 and 350.

Researchers tracked the men’s medical histories, medication use, signs and symptoms of hypogonadism, and depressive symptoms and/or a known diagnosis of depression or use of an antidepressant. They found depression and/or depressive symptoms were present in 56 percent of the men.

In addition, one quarter of the men in the study were taking antidepressants and that the men had high rates of obesity and low rates of physical activity. The most common symptoms were erectile dysfunction, decreased libido, fewer morning erections, low energy, and sleep disturbances.

Lead researcher Michael S. Irwig, M.D., said the findings are not only relevant for men with low levels of the male hormone, but also those who are within the normal range, but on the low end.

"In an era where more and more men are being tested for ‘Low-T’ — or lower levels of testosterone — there is very little data about the men who have borderline low testosterone levels," said Dr. Irwig, associate professor of medicine and director of the Center for Andrology at the GW School of Medicine and Health Sciences. "We felt it important to explore the mental health of this population."