Testosterone is one of the primary sex hormones found in men, but also, to a much lesser extent, in women. In males, testosterone is responsible for the development of the penis and testes, pubescent changes, muscle size and strength, libido and sperm production. In women, testosterone helps regulate ovary function and bone mineralization. The hormone has also been linked to normalizing mood.
Testosterone Deficiency
Testosterone deficiency is not very common, according to 2007 research by scientists from the New England Research Institutes in Watertown, Mass. In a random collection of data on 1,475 Boston-area men between the ages of 30 to 79, 24 percent had low total testosterone. Low levels are defined as having less than 300 nanograms per deciliter, or ng/dL of total testosterone and less than 5 ng/dL of free testosterone. Low levels of the hormone can cause reduced libido, erectile dysfunction, osteoporosis, increased risk for bone fractures and a variety of psychological and physical symptoms, including disturbed sleeping habits, depression and diminished physical performance. In the New England study, nearly 52 percent of men over the age of 49 with low testosterone levels had symptoms.
Testosterone and Depression
In 2004, research from the University of Washington School of Medicine found that men with low testosterone levels are 4.2 times more likely to be diagnosed with depression. According to the study, published in the "Archives of General Psychiatry," about 30 percent of men over the age of 55 commonly experience testosterone deficiency. After analyzing clinical records of 278 men 45 and older, the researchers found that 21.7 percent with low testosterone levels were diagnosed with depression, versus only 7.1 percent of men with normal hormone levels.
Supplements
Testosterone supplementation may be helpful for men who have depression that is resistant to antidepressants. In a 2003 study published by the "Journal of Psychiatry," men between the ages of 30 and 65 were administered a topical testosterone gel for the treatment of drug-resistant depression for eight weeks. The men receiving the supplement reported greater improvement in depression scores compared to those on a placebo. The testosterone seemed to improve certain aspects of depression, including mood, guilt and anxiety.
Aging
Testosterone levels peak during adolescence and early adulthood, according to the Mayo Clinic. With age, levels naturally decline at a rate of about 1 percent per year, starting after the age of 30. Men who have the telltale signs of testosterone deficiency may not necessarily have low levels of the hormone, however. There are many other reasons why a man experiences insomnia, reduced muscle mass and emotional changes, including side effects from medications, thyroid problems or substance abuse. One way to find out for sure is by getting a blood test from your doctor.
References
- University of Washington School of Medicine: Low Testosterone Levels Associated With Depression; February 2004
- Medscape: Testosterone Gel Helpful in Refractory Depression; January 2003
- Science Daily: Testosterone Deficiency Relatively Rare in Men; September 2007
- Mayo Clinic: Testosterone Therapy: Key to Male Vitality?; April 2010
