Finasteride has a wide range of effects on the human body/mind but in the medical world everything is based on symptoms due to the gross lack of knowledge about the human body/mind.
These are a couple of articles that focus on finasteride and the brain.
finasteride should prevent the conversion of progesterone to 5 alpha DHP and of deoxycorticosterone to 5 alpha DHDOC.
-as such it should induce increased anxiety and depression and seizure susceptibility.
And this is seen in many animal studies
Depression/Anxiety
-Case reports of human depression/anxiety induced by finasteride have reported (1)
-double blind placebo studies have revealed
- Finasteride improvement in quality of life for BPH and Androgenetic Alopecia patients (2,3)
- more depression side effects in placebo then finasteride (4)
-animal studies found Finasteride may be useful for increased excitability and dysphonic symptoms in premenstrual and postpartum disorder
conclusion: animal studies support the depressogenics of the finasteride but has produced mixed results in humans. This may be because finasteride blocks both 1 and 2 isoforms of 5 alpha reductase in rats but only Type 2 in humans.
Seizure
-men with epilepsy taking finasteride long-term may have increased seizure susceptibility (5)
-Finasteride has been shown in a Case study to stop the anti-seizure effects of progesterone in Catamenial epilepsy (6)
- finasteride may increase chances of stress induced seizure (7)
Sexual Behaviour
No idea.
Maybe the liver releases proteins to stop finasteride but the proteins just end up being a Sex Hormone Binding Gobulin (SHBG) and attaching themselves to free-testosterone.
Alcohol
-finasteride blocks the 5-alpha-DHP effects of alcohol (reduces effects of alcohol in humans) (8)
- may reduce withdrawal symptoms of alcohol in men if taken before alcohol dependence (9) (10) (11)
conclusion: some mechanisms of finasteride and alcohol are unknown
but finasteride reduces the effects and withdrawal of alcohol.
Neurological disorders
Finasteride in the nucleus accumben counters sensorimotor gating deficits induced by dopaminergic activation
This makes finasteride useful for treating Tourette’s Syndrome (12), which has been seen in a case study (13)
finally Finasteride has been shown to treat the pathological gambling in patients with Parkinson disease through its effects on dopamine receptors. Finasteride did not worsen Parkinson disease. (14)
Finasteride is an antipsychotic
Finasteride antagonized prepulse inhibition (PPI) defects induced by apomorphine and d-amphetamine just like haloperidol and clozapine. (15)
-This makes finasteride useful for schizophrenia spectrum disorders
there is a case report where a patient with schizophrenia has been successfully treated with finasteride. (16)
References:
1. Altomare G. Capella GL. Depression circumstantially related to the administration of finasteride for androgenetic alopecia. J Dermatol 2002;29:665-669
2. YAMAZAKI, Masashi, eta al. Oral finasteride improved the quality of life of androgenetic alopecia patients. The Journal of Dermatology. vol 38, iss 8. PB Blackwell Publishing Ltd, 2011
3. C. Bruskewitz, PLESS Study Group, Impact of baseline PSA level on quality of life measures of general health and sexual satisfaction/drive in men with BPH treated with finasteride or placebo, European Urology Supplements, Volume 2, Issue 1, February 2003, Page 74, ISSN 1569-9056, 10.1016/S1569-9056(03)80292-0.
4. Ciotta L, Cianci A, Calogero AE, et al. Clinical and endocrine effects of finasteride, a 5a-reductase inhibitor, in women with idiopathic hirsutism. Fertil Steril 1995;64:229-306
5. Kaminski RM, Marini H, Kim WJ, Rogawski MA. Anticonvulsant activity of androstrrone and etiocholanolone. Epilepsia 2005;46:819-827
6. Herzog AG, Frye CA. Seizure exacerbation associated with inhibition of progesterone embolism. Ann Nurol 2003;53:390-391
7. Reddy DS. Is there a physiological role for the neurosteriod THDOC in stress-conditions? Trends Pharmacol Sci 2003;24:103-106
8. Pierucci-Lagha A, Covault J, Feinn R, eta al. GABRA2 alleles moderates the subjective effects of alcohol, which are attenuated by finasteride. Neuropsychopharmacology 2005;30:1193-1203.
9. Finn DA, Ford MM, Wiren KM, Roselli CE, Crabbe JC. The role of Pregnane neurosteriods in ethanol withdrawal: Behavioural geneitic approaches. Pharmacol Ther 2004;101:91-112
10. Gorin-meyer RE, Wiren KM, Tanchuck MA, Lon SL, Finn DA. Sex differneces in the effect of finasteride on acute ethanol withdrawal severity in C57BL/6J and DBA/2J mice. Submitted.
11. Gisleskog PO, Hermann D, Hammarlund-Udenaes M, Karlsson MO. A model for the turnover of dihydrotestosterone in the presence of the 5a-reductase inhibitors GI198745 and finasteride. Clin Pharmacol Ther 1998;64:636-647
12. Paola Devoto, et al. Inhibition of 5α-reductase in the nucleus accumbens counters sensorimotor gating deficits induced by dopaminergic activation, Psychoneuroendocrinology, Volume 37, Issue 10, October 2012, Pages 1630-1645, ISSN 0306-4530, 10.1016/j.psyneuen.2011.09.018.
13. Treatment of Tourette's Syndrome With Finasteride Bortolato, Marco;Muroni, Antonella;Marrosu, Francesco The American Journal of Psychiatry; Dec 2007; 164, 12; ProQuest pg. 1914
14. Bortolato, Marco MD, PhD; Finasteride Attenuates Pathological Gambling in Patients With Parkinson Disease. Journal of Clinical Psychopharmacology. Issue: Volume 32(3), June 2012, p 424–425
15. Bortolato, Marco, eta al. Antipsychotic-Like Properties of 5-[alpha]-Reductase Inhibitors. Neuropsychopharmacology. American College of Neuropsychopharmacology 0893-133X
16. Koethe, D., Bortolato, M., Piomelli, D., Leweke, F.M., 2008. Improvement of general symptoms in a chronic psychotic patient treated with finasteride: case report. Pharmacopsychiatry 41, 115e116.