The 203 men who met the criteria for depression had significantly lower total and free (not bound to proteins) testosterone levels than those who weren’t depressed. After controlling for other factors, such as cognitive scores, education level and body-mass index, the researchers concluded that men in the lowest quintile (20 percent) of free testosterone were three times more likely to have depression compared to those in the highest quintile.
The findings were published in the March issue of the Archives of General Psychiatry.
While more research is needed to determine how low hormone levels may be linked to depression risk, the study authors believe it may be caused by changes in the levels of neurotransmitters or hormones in the brain.
