Testosterone Can Prevent Depression, Study Suggests

Testosterone

Testosterone, the principal male sex hormone, can prevent depression – a mood disorder characterized by  loss of interest or pleasure in everyday activities, accompanied by other signs like lack of appetite, fatigue and sleep disorders. The exact mechanisms of the antidepressant effect of this hormone are not yet known, but Nicole Carrier and Mohamed Kabbaj, scientists at Florida State University are trying to figure them out. They reported their discoveries in an article for the Biological Psychiatry , the official journal of the Society of Biological Psychiatry, one of the most selective and highly cited journals in the field of psychiatric neuroscience.

Testosterone Vial

Their findings are that there is a specific pathway in the hippocampus that mediates testosterone’s effects. The hippocampus is a part of the limbic system – a set of brain structures that play an important role in emotion, long-term memory, behaviour and also olfaction.

The hypothesis for this study emerged from the fact that women are twice as much predisposed to develop depression that men. Also, men suffering from hypogonadism (which is a decrease in the activity of the gonads, resulting in lower levels of testosterone) have more signs of depression and anxiety which appear to be alleviated by testosterone replacement therapy.

Knowing how testosterone affects emotions in humans is of a great importance because this may lead the way to the  development of a new generation of antidepressant therapies.  To find how does testosterone influence the processes in the brain, scientists performed many experiments on male rats that were previously neutered. All the rats developed behaviors that are linked to depression, and these behaviors were reversed with testosterone replacement therapy.

Mohamed Kabbaj explains that “we have identified a molecular pathway called MAPK/ERK2 (mitogen activated protein kinase/ extracellular regulated kinase 2) in the hippocampus that plays a major role in mediating the protective effects of testosterone.” This pathway could be a target for new antidepressants. This finding that in order to record the antidepressant effects of testosterone, it is necessary that the ERK2 protein functions properly.

Kabbaj added, “Interestingly, the beneficial effects of testosterone were not associated with changes in neurogenesis (generation of new neurons) in the hippocampus as it is the case with other classical antidepressants like imipramine and fluoxetine.”

Other studies made by the same group have shown that the antidepressant effect of testosterone can only be observed in the male rats. Female rats with depression-associated behaviors do not seem to benefit from the testosterone therapy.