Background:Finasteride is a competitive inhibitor of 5 alpha-reductase enzyme, and is used for treatment of benign prostatic hyperplasia and androgenetic alopecia. Animal studies have shown that finasteride might induce behavioral changes. Additionally, some cases of finasteride-induced depression have been reported in humans. The purpose of this study was to examine whether depressive symptoms or anxiety might be induced by finasteride administration.Methods:One hundred and twenty eight men with androgenetic alopecia, who were prescribed finasteride (1mg/day) were enrolled in this study. Information on depressed mood and anxiety was obtained by Beck Depression Inventory (BDI), and Hospital Anxiety and Depression Scale (HADS). Participants completed BDI and HADS questionnaires before beginning the treatment and also two months after it. Results:Mean age of the subjects was 25.8(+/- 4.4) years. At baseline, mean BDI and HADS depression scores were 12.11(+/-7.50) and 4.04(+/-2.51), respectively. Finasteride treatment increased both BDI (p