Treatment of male rats with finasteride, an inhibitor of 5alpha-reductase enzyme, induces long-lasting effects on depressive-like behavior, hippocampal neurogenesis, neuroinflammation and gut microbiota composition.

Our findings indicate that finasteride treatment causes several alterations in the hippocampus that are detected at the end of the treatment… coincide with the apparition of depressive-like behavior, suggesting that long term effects of finasteride treatment on neurogenesis and neuroinflammation may participate in the enduring effects of the drug on depressive-like behavior, which are detected even one month after stopping the administration of the drug… Since neuroactive steroids regulate neurogenesis, gliosis and neuroinflammation and since PFS patients also show changes in neuroactive steroid levels, the effect of finasteride on depression, neuroactive steroid levels, neurogenesis and neuroinflammation may be interrelated events. In addition, the changes here observed at the end of treatment and at withdrawal on gut microbiota may depict further possible signals involved in the so call gut microbiota-brain axis.

Diviccaro S, Giatti S, Borgo F, Barcella M, Borghi E, Trejo JL, Garcia-Segura LM, Melcangi RC. 2018 Sep 18;99:206-215. doi: 10.1016/j.psyneuen.2018.09.021. [Psychoneuroendocrinology]