A study in the latest issue of the American Journal of Psychiatry says that men who don't respond to antidepressants may have low testosterone levels, and efforts to restore those levels to normal seem to improve their depression.
In screening the testosterone levels of 54 depressed men who didn't benefit from antidepressants, researchers at McLean Hospital in Belmont, Mass., found that a relatively large number -- 43 percent -- of the men had low testosterone levels.
The researchers gave 19 of those men a testosterone replacement gel along with antidepressants, while the other five received antidepressants and a placebo. The subjects were between the ages of 30 and 65.
Over the next eight weeks, those who received the testosterone gel showed significant improvements compared to those who didn't get the gel. Areas of improvement included mood, feelings of guilt and anxiety, as well as improved sleep, appetite and libido.
Side effects from the treatment were modest; one man withdrew from the study due to difficulty urinating.
The researchers caution that the findings are preliminary, and larger studies are needed. However, they say the initial results suggest that men who don't respond to antidepressants may have reduced testosterone levels, and doctors should consider screening for that problem.
McLean Hospital is a psychiatric affiliate of Harvard Medical School.
The National Institute of Mental Health offers information on the difference in depression between men and women.