A recent study presents further evidence that the drug Risperdal can cause gynecomastia — more popularly known as “man boobs.”

The final report has not yet been published. However, the study’s lead author, Dr. Mahyar Etmian, presented data at the March 15 American Association for Geriatric Psychiatry (AAGP) meeting. It is not unusual for researchers to present the data from papers prior to publication at meetings and symposia as a means of getting feedback from peers.

Etmian’s study looked at data collected in health claims databases, a type of health database maintained by insurance companies. Her research team discovered that people taking Risperdal had a 69 percent increase in their risk of developing unnatural breast growth compared to those that did not. This is not the first study to find evidence of a link between the growth of male breasts and Risperdal.

Research has suggested that Risperdal can disrupt hormones in male patients, causing them to produce a hormone called progestin. In healthy women, progestin causes breast growth. Unfortunately, it has the exact same effect on male Risperdal users. The effect is most pronounced in younger male Risperdal users.

The makers of Risperdal have also faced litigation and government sanction over their marketing practices. Allegedly, the manufacturers of Risperdal were involved in promoting off-label uses for the drug. Many drugs can work against disorders other than those that drug companies have received approval for. Physicians in the U.S. are allowed to prescribe drugs in cases like this, usually based on preliminary data. However, drug companies are only allowed to promote a drug for uses the Food and Drug Administration has specifically tested for safety. The manufacturers of Risperdal are also facing legal action over the allegation that they actively marketed the drug for purposes other than schizophrenia, bipolar disorder, and irritability/aggression associated with autism.

Dozens of individual Risperdal lawsuits and a Risperdal class action lawsuit investigation have been filed. These lawsuits allege that the drug’s manufacturers have known about the risk of male breast growth associated with their drug, but continued to produce the drug anyway, downplaying the risks. These cases may be combined into a single legal proceeding called a Mass Tort.

A Mass Tort is a type of group lawsuit, like the more familiar class action lawsuit. In both a Risperdal class action lawsuit and a Mass Tort, a group of people allege that they have suffered harm at the hands of the same defendant. In a Risperdal class action lawsuit, typically the group of plaintiffs are organized as a group from the earliest stages of the lawsuit. However, in Mass Torts, plaintiffs file separate lawsuits across various court districts, which are later coordinated and consolidated into a single MDL. In drug lawsuits, MDLs are more common than class action lawsuits.