In a group of 61 otherwise healthy former users of finasteride who developed persistent sexual side effects, depressive symptoms were present and categorized as mild in 11% of users, moderate in 28% of users, and severe in 36% of users. Suicidal thoughts were present in 39% of former finasteride users, and an additional 5% chose the statement “I would like to kill myself.” The corresponding rates of depressive symptoms and suicidal thoughts were significantly lower in a control group of young men with male pattern hair loss who had not used finasteride and who did not have any current or past psychiatric conditions or use of psychiatric medications. It turns out that finasteride crosses the blood-brain barrier and blocks the enzyme 5α-reductase, which reduces the concentrations of multiple neuroactive steroids derived not only from testosterone but also from progesterone and deoxycorticosterone… reduced concentrations of neuroactive steroids are associated with depression in several human studies. Although the effects of finasteride in the human brain are poorly understood, clinicians, as well as potential finasteride users, should be aware of the serious potential risks of this medication, especially as it is being used cosmetically to alter a normal age-related process. This is the first study to document suicidal thoughts in (former) users of finasteride.
Irwig MS. Depressive symptoms and suicidal thoughts among former users of finasteride with persistent sexual side effects. J Clin Psychiatry. 2012 Sep;73(9):1220-3. doi: 10.4088/JCP.12m07887. Epub 2012 Aug 7. [PubMed]