In this paper we report 19 patients (14 males, 5 females; mean age 28.16 years +/- 7.68 SD) out of a series of 23 (17 males, 5 females) who developed a mood disturbance (moderate to severe depression) during treatment with finasteride, 1 mg/day orally, for androgenetic alopecia (Hamilton subtypes III-V; Ludwig subtypes I-II). Depression, which significatively impaired sociofamilial relations, sleep and eating behaviour, was associated to marked anxiety in some cases, developed after 9-19 weeks of treatment with finasteride, and promptly resolved after suspension of the drug. Two patients accepted reintroduction of the drug, and depression relapsed within 2 weeks. Depression as an adverse effect of finasteride has been reported only once. Further studies are needed to confirm our circumstantial observations, which are based on a retrospective series of patients.