Can finasteride (a 5-alpha-reductase inhibitor) affect mood and what percentage of people taking it experience mood changes?

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Finasteride's Effects on Mood

Yes, finasteride can affect mood, with approximately 0.5-0.6% of patients developing depression and anxiety, particularly those taking it for androgenetic alopecia. 1

Mood-Related Side Effects of Finasteride

  • Finasteride has been associated with mood disturbances, including depression and anxiety, though these effects occur in a relatively small percentage of patients 2, 1
  • In a large population-based case-control study, patients taking finasteride 1mg daily for androgenetic alopecia showed higher rates of anxiety (0.6% vs 0.4% in controls) and depression (0.5% vs 0.4% in controls) 1
  • Multivariate analysis confirmed finasteride as a risk factor for both anxiety (OR 1.449) and depression (OR 1.003) in patients with androgenetic alopecia 1
  • Interestingly, patients taking higher doses (5mg) for benign prostatic hyperplasia did not show significantly increased rates of psychiatric disorders compared to controls 1

Mechanism of Mood Effects

  • Finasteride inhibits 5α-reductase enzyme, which is responsible for converting hormones like testosterone and progesterone into their 5α-reduced derivatives 3
  • These 5α-reduced neurosteroids (particularly allopregnanolone) have natural anxiolytic and antidepressant properties in the brain 3
  • Even low-dose finasteride (1mg/day) has been shown to decrease levels of these neuroactive steroids, which may contribute to mood disturbances 3
  • Animal studies have demonstrated that short-term finasteride administration can induce anxiety-like and depression-like behaviors in rats, associated with impaired synaptic plasticity and cognitive function 4

Clinical Presentation and Time Course

  • Mood disturbances typically develop after 9-19 weeks of treatment with finasteride 5
  • Symptoms can include moderate to severe depression that significantly impairs social relationships, sleep, and eating behavior 5
  • In some cases, depression is accompanied by marked anxiety 5
  • In a prospective study, finasteride treatment significantly increased Beck Depression Inventory scores and Hospital Anxiety and Depression Scale depression scores 2

Resolution of Symptoms

  • Mood symptoms typically resolve promptly after discontinuation of finasteride 5
  • However, some case reports suggest that symptoms may persist in certain individuals even after stopping the medication 4
  • In a small case series, reintroduction of finasteride in patients who had previously experienced depression led to relapse of depressive symptoms within 2 weeks 5

Risk Factors and Monitoring

  • Patients with a history of depression or anxiety may be at higher risk for developing mood-related side effects 2
  • Finasteride should be prescribed cautiously for patients with high risk of depression 2
  • Regular monitoring for mood changes is advisable, particularly during the first 4-5 months of treatment 5

Other Common Side Effects for Context

  • Sexual side effects are more common than mood disturbances, with erectile dysfunction occurring in approximately 4.7% of patients during the first 6 months 6
  • Decreased libido is reported in about 3% of patients initially, decreasing to 0.3% by 19-24 months 6
  • Ejaculation disorders occur in approximately 1.4% of patients initially 6
  • Overall discontinuation rates due to all adverse events are approximately 6-7% 6

Clinical Implications

  • When prescribing finasteride, patients should be informed about the potential for mood changes, though the absolute risk is relatively small 1
  • For patients who develop significant depression or anxiety while on finasteride, discontinuation of the medication should be considered 5
  • The risk-benefit assessment should weigh the benefits of finasteride against potential side effects, including mood disturbances 6

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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