Is finasteride (a 5-alpha-reductase inhibitor) effective for treating anxiety?

Finasteride Should Not Be Used to Treat Anxiety

Finasteride is not indicated for anxiety treatment and may actually worsen or induce anxiety and depressive symptoms, particularly in younger men being treated for androgenetic alopecia.

Evidence Against Finasteride for Anxiety

Established Indications Do Not Include Psychiatric Conditions

• Finasteride is FDA-approved exclusively for benign prostatic hyperplasia (BPH) and androgenetic alopecia, with no psychiatric indications 1.
• The American Urological Association guidelines comprehensively review finasteride's effects and make no mention of any anxiolytic properties 1.

Finasteride May Induce or Worsen Anxiety

• A large population-based case-control study of 23,227 men with androgenetic alopecia found that finasteride users had significantly higher rates of anxiety compared to controls (0.6% vs 0.4%, p = 0.04), with finasteride identified as an independent risk factor for anxiety (OR 1.449, p = 0.002) 2.
• A prospective study of 128 men treated with finasteride 1 mg daily for androgenetic alopecia showed increased Hospital Anxiety and Depression Scale (HADS) anxiety scores, though the difference did not reach statistical significance (p = 0.061) 3.
• Animal studies demonstrate that short-term finasteride administration (6 days) induces anxiety-like behavior in multiple validated tests including the elevated plus maze, open field test, light/dark test, and novelty suppressed feeding test 4.

Finasteride Is Associated With Depression

• Meta-analysis revealed that finasteride treatment is associated with significantly increased risk of depressive symptoms, with a pooled odds ratio of 2.14 (95% CI: 1.40-3.27, p < 0.0001) 5.
• The crude pooled rate of depressive symptoms with finasteride was 3.33% versus 2.54% without finasteride (p < 0.0001) 5.
• In the androgenetic alopecia population, finasteride was identified as an independent risk factor for depression (OR 1.439, p = 0.003) 2.
• A prospective study demonstrated that finasteride treatment significantly increased both Beck Depression Inventory scores (p < 0.001) and HADS depression scores (p = 0.005) after just two months of treatment 3.

Severe Psychiatric Risks

• Risk of suicidal ideation or behavior was substantially greater with finasteride versus without (21.2% vs 14.0%, p < 0.0001) 5.
• Case series have documented moderate to severe depression developing after 9-19 weeks of finasteride treatment, with symptoms promptly resolving after drug discontinuation and relapsing within 2 weeks upon rechallenge 6.

Mechanism of Psychiatric Effects

• Finasteride inhibits 5α-reductase, which not only reduces dihydrotestosterone but also affects neurosteroid synthesis in the brain 3, 4.
• Animal studies show that finasteride decreases hippocampal synaptic plasticity and long-term potentiation, mechanisms critical for mood regulation and anxiety control 4.
• Finasteride may increase plasma corticosterone levels, potentially contributing to anxiety and depression through HPA axis dysregulation 4.

Clinical Implications

• Finasteride should be prescribed cautiously, if at all, to patients with pre-existing anxiety disorders or high risk of depression 3.
• The American Urological Association acknowledges that sexual dysfunction and other adverse effects occur with finasteride, though psychiatric effects receive less emphasis in BPH guidelines 1.
• Psychiatric symptoms may persist even after finasteride discontinuation in some patients, a phenomenon recognized by the FDA through label amendments 7, 5.

Common Pitfalls to Avoid

• Do not prescribe finasteride for off-label psychiatric indications—there is no evidence of benefit and substantial evidence of harm 3, 2, 5.
• Do not dismiss patient reports of anxiety or depression during finasteride treatment as unrelated to the medication 3, 6.
• Do not assume that psychiatric effects only occur at higher doses used for BPH (5 mg)—the 1 mg dose for alopecia shows similar or greater psychiatric risk 2, 5.