Beyond inducing sexual dysfunction, finasteride may contribute to a range of neuropsychiatric issues. Neurosteroids, which are generated in the brain, are vital for the upkeep of central nervous system (CNS) activities, and their production is regulated by 5α-reductase enzymes. By blocking 5α-reductases, finasteride reduces neurosteroid levels, a change that has been correlated with the onset of depression. Furthermore, finasteride can adversely affect nerve and blood vessel integrity, which might contribute to conditions like muscle atrophy, muscle soreness, and joint pain.
—Post-Finasteride Syndrome and Sexual Dysfunction: iCliniq, August 13, 2024