AbstractBackgroundThere is a long‐standing debate if finasteride, a medication used to treat benign prostatic hyperplasia (BPH) and androgenetic alopecia (AGA), can cause psychiatric side effects.ObjectiveThe goal of this large‐scale population‐based study was to determine whether finasteride therapy for BPH and AGA is associated with the emergence of mental health conditions.MethodsThis observational case–control study compared the data from patients with BPH who received finasteride 5 mg daily and patients with AGA who received finasteride 1 mg daily with age‐ and gender‐matched controls. The incidence of psychological health outcomes such as depression, anxiety, neuroses, bipolar disorder, schizophrenia, psychoses and alcohol abuse within 2 years of the initiation of finasteride therapy has been evaluated and compared between the finasteride groups and controls.ResultsThe BPH group included 307 men with a mean age of 61.5 (±17.4) years and 1218 controls. Mental health outcomes recorded in 2.3% of the patients, with no significant increase in rate when compared to controls. The AGA group consisted of 23,227 men with a mean age of 31.4 (±10.3) years and 39,444 controls. One percent of AGA patients developed psychiatric disorders. In comparison to controls, patients with AGA had higher rates of anxiety and depression (0.6% vs. 0.4%, p = 0.04, and 0.5% vs. 0.4%, p = 0.007, respectively). In multivariate regression models, finasteride was found as one of the risk factors for anxiety (OR 1.449, p = 0.002) and depression (OR 1.439, p = 0.003) when stratified to age, sector, socioeconomic status and comorbidities.ConclusionsAccording to our research, finasteride users had a very low rate of adverse mental health effects, with no increase in psychological sequelae in BPH patients and a slight increase in anxiety and depression in AGA patients.