Elite and pro athletes using drugs to enhance performance is nothing new. But poker players? Really?

Researchers from Nova Southeastern University in Florida interviewed 198 professional, semi-pro, amateur and recreational players from the U.S. and around the world about their use of cognitive and performance-enhancing drugs, as well as dietary supplements and other substances, to improve performance while playing poker. The preliminary results of the study were presented recently at the annual meeting of the College of Psychiatric and Neurologic Pharmacists in San Antonio, Texas.

Among the players (most of them men in their mid-20s), 28% said they took at least one prescription medication to improve their performance. Of those who took a cognitive and performance-enhancing medication, 73% said it was to help them focus or concentrate. The most popular medications were amphetamines or dextroamphetamines, followed by benzodiazepines (tranquilizers), hydrocodone (a painkiller), and methylphenidate (usually used to treat attention deficit disorders).

As to how they got the medications, 38% obtained them from a physician, 26% were given the drugs by players, 26% bought drugs from players and 10% purchased them online.

Prescription drugs weren't the only substances players relied on—80% of the 198 players took some other substance to improve performance: 71% used caffeine, 51% drank energy drinks, 34% smoked marijuana and 30% used alcohol. In addition, 46% took a dietary supplement such as vitamin B-12 or guarana.