A new study found that Risperdal, the popular anti-psychotic drug found to cause male breast enlargement in young boys, can also have the same side effect in older men.

Older men who use Risperdal had a 69 percent higher risk of developing the condition known as gynecomastia than nonusers, according to information presented at the American Association for Geriatric Psychiatry’s annual meeting in 2014. The study was based on a review of national health claims.

“This is the first and largest epidemiologic study on this question using data from 1 million men in the United States,” said the study’s lead author, Mahyar Etminan, who is a drug safety researcher and assistant professor at the University of British Columbia in Vancouver, Canada.

In 1993, the U.S. Food and Drug Administration (FDA) approved Risperdal for the treatment of schizophrenia. It was later approved for use in children and to treat adolescent schizophrenia and bipolar disorder in children ages 10 to 17, irritability in children 5 to 16 years of age with autistic disorder, aggression and other behavior disorders. It is also sometimes prescribed for off-label uses, including the treatment of ADHD in children.

Hundreds of Risperdal lawsuits have since been filed accusing manufacturer Johnson & Johnson and its subsidiaries of concealing the drug’s side effects, including causing gynecomastia, a condition in which young boys develop large breasts. The cases are part of a consolidated litigation in Pennsylvania.

Risperdal lawsuits accuse the manufacturer of failing to adequately warn boys prescribed the medication that the trauma of breast development was a possible side effect and that surgery might be needed to have the breasts removed.

Risperdal remains one of the most frequently prescribed medications in the world.

Commonly known as “man boobs,” gynecomastia frequently requires surgical correction. Health experts believe the anti-psychotic medication dramatically increases prolactin levels, leading to the development of breasts.

In 2012, Johnson & Johnson reached a confidential settlement with a 21-year-old man who filed a Risperdal lawsuit and underwent a mastectomy after growing breasts, something he said resulted in “severe psychological trauma.”

Shortly after the Risperdal gynecomastia settlement, Johnson & Johnson settled cases brought on behalf of at least five other boys who experienced similar breast development.

The mental anguish of being bullied and teased results in depression, anxiety and insecurity in young men already battling mental health issues.

In response to increased interest about the risk of Risperdal gynecomastia, Etminan said the study looked at whether Risperdal users suffered gynecomastia more than users of other antipsychotics.

Researchers looked at information from the IMS LifeLink Health Plan claims database for 1 million men in the United States between the ages of 45 and 80 who made claims between 2001 and 2011. Within that group, 8,285 cases of gynecomastia were identified.

“It was fairly consistent with what we already know about Risperdal,” Dr. Iqbal Ahmed, clinical professor of psychiatry and geriatric medicine at the University of Hawaii at Manoa told Medscape Medical News.

“Among antipsychotics, it’s most likely to cause gynecomastia in some men, probably because of higher prolactin levels. I think it’s a confirmatory poster with a larger dataset rather than just clinical experience.”