Propecia Side Effects Linked to Increased Risk of Depression: Study

A new study suggests that side effects of Propecia, as well as similar drugs like Proscar and Avodart, may increase the risk of depression.

All three drugs are part of a class of medications known as 5α-reductase inhibitors (5-ARIs), with Propecia approved for treatment of hair loss, and Avodart and Proscar used as prostate drugs.

In this latest study, Swedish researchers found that while the medications are unlikely to increase the risk of dementia and Alzheimer’s disease, their use does appear to increase the risk of depression. The findings were published on December 22 in JAMA Network Open.

Propecia (finasteride) is a prescription medication marketed by Merck to help men restore natural hair loss that occurs with male pattern baldness, and concerns have been raised concerns about the drug makers’ failure to disclose potential side effects, since it does not treat a medical condition that poses any health risks.

The active pharmaceutical ingredient was originally developed by Merck as a niche treatment for enlarged prostate, and marketed as Proscar in 1992. However, it is now most widely used for treatment of male pattern baldness under the brand name Propecia, and aggressively marketed in direct-to-consumer advertisements that encourage men to contact their doctors about the prescription.

In this new study, researchers conducted a Swedish register-based cohort involving 2,236,876 men from ages 50 to 90 between July 1, 2005, and December 31, 2018. They looked for cases of dementia, Alzheimer’s disease, vascular dementia, depression or suicide, as well as use of one of the three drugs.

According to the findings, early indications of Alzheimer’s and dementia decreased over time until they became statistically insignificant over four years, which researchers say suggests Propecia side effects were not the cause.

The risk of depression with Propecia and Proscar, both of which use finasteride as their active ingredient, increased by more than 60%, while the use of Avodart (dutasteride) increased the risk of depression by nearly 70%. However, the researchers indicated the drugs were not linked to an increased risk of suicide, which contradicts some previous studies’ findings.

“Both finasteride and dutasteride were similarly associated with depression with a constant risk over time, while neither drug was associated with suicide,” the researchers concluded. “Prescribing clinicians and potential users should be aware of the possible risks for depression associated with 5-ARI use.”

Propecia Depression and Suicide Side Effects

According to court records revealed in February 2021, Merck & Co., the manufacturer of Propecia, received reports involving Propecia suicide problems among men before 2011, when the manufacturer decided not to add a label warning to the drug.

By that time, the FDA has received at least 34 reports involving suicide and suicidal thoughts that may have been linked to side effects of Propecia, including at least 10 deaths. Since refusing to add the warning, the FDA received more than 700 additional reports about the problems.

In 2009, Merck had already received more than 200 reports of depression, including suicidal thoughts, linked to Propecia use. Those findings were outlined in an internal risk assessment report within the company that same year. However, Merck executives determined there were not enough of such reports to merit a label warning.

Propecia Sexual Dysfunction Lawsuits

While men generally take the medication to help improve their appearance and overall quality of life, the drug maker previously faced a number of Propecia lawsuits filed by men who allege that they have been left with permanent sexual complications, such as erectile dysfunction, decreased libido, genital shrinkage and problems with cognition.

According to allegations raised in the complaints, Merck has failed to adequately warn consumers or the medical community about the link between Propecia and sexual dysfunction, which may continue long after the medication is no longer used.

Prior warning information provided by the drug maker suggested that sexual dysfunction associated with the medication was rare, and that the problems resolve after use of the medication is discontinued.

Even after many men reported experiencing permanent sexual issues after Propecia use, Merck continued to provide information suggesting that the problems were temporary until the Propecia sexual dysfunction warning label was updated in April 2012.