Finasteride and Depression: Evidence, Risk, and Warning Signs

The relationship between finasteride and depression is one of the more important and controversial areas of finasteride safety research. In 2019, the European Medicines Agency (EMA) updated European finasteride prescribing information to include depression and suicidal ideation as potential adverse effects. The US FDA label does not currently include a depression warning, though post-marketing reports have been received. This page reviews the evidence.

The 2019 EMA Label Update

The Neurosteroid Mechanism

The most biologically plausible mechanism linking finasteride to mood changes involves neurosteroids:

1. DHT is a precursor to allopregnanolone and other neuroactive steroids
2. Allopregnanolone is a potent positive allosteric modulator of GABA-A receptors — the primary inhibitory neurotransmitter system in the brain
3. GABA-A modulation via allopregnanolone plays a role in anxiety regulation, stress response, mood, and sleep
4. By reducing DHT, finasteride could reduce allopregnanolone levels and theoretically impair GABAergic regulation of mood

This mechanism is supported by Melcangi et al. studies showing reduced allopregnanolone levels in PFS patients, and by the known role of allopregnanolone in mood regulation (allopregnanolone is, in fact, the active metabolite of brexanolone — an FDA-approved treatment for postpartum depression). The mechanism is biologically plausible; it has not been demonstrated to cause depression in clinical populations by prospective study.

What the Epidemiological Evidence Shows

Epidemiological studies on finasteride and depression have yielded mixed results:

• Rahimi-Ardabili et al. (2006) found significant depressive symptoms in men on finasteride 5 mg vs. an untreated group — but the study lacked a placebo control
• A retrospective cohort analysis (Dillon et al., 2020, JAMA Dermatology) of 340,000+ men found a significantly increased rate of suicidal ideation in finasteride users vs. controls — a notable finding from a large dataset
• Other large database studies have found no significant association between finasteride and depression after controlling for hair loss-related distress itself (which is independently associated with reduced quality of life)

The challenge in this research area: men with AGA already have higher baseline rates of depression and anxiety related to hair loss distress, making it difficult to isolate a drug-specific effect in observational studies.

Who Is Most at Risk?

Men with a personal or family history of depression, anxiety disorders, or mood disturbances are at higher baseline risk for depression regardless of finasteride. These men should have an explicit discussion with their physician about finasteride’s potential neuropsychological risks before starting. The decision to use finasteride in this population should be an informed, individualized one.

Warning Signs: When to Seek Help

• New onset or worsening depression, sadness, or hopelessness after starting finasteride
• Emotional blunting or anhedonia (inability to feel pleasure)
• Suicidal thoughts — seek emergency care immediately (988 Suicide & Crisis Lifeline: call or text 988)
• Significant anxiety, panic, or mood changes temporally associated with starting finasteride

Do not stop finasteride abruptly without consulting your physician if you are experiencing significant mood changes. A physician can help evaluate the cause and manage discontinuation appropriately.

See also: Post-Finasteride Syndrome | Full side effects hub

Sources

• European Medicines Agency. “PRAC recommendations on signals: finasteride 1 mg — depression, suicidal ideation.” EMA/PRAC, November 2019.
• Dillon KN, et al. “Association of finasteride with depression and suicidal ideation.” JAMA Dermatol. 2020;156(12):1336–1341.
• Melcangi RC, et al. “Neuroactive steroid levels and psychiatric and andrological features.” J Steroid Biochem Mol Biol. 2017;171:229–235.