The men — and their spouses — also were subjected to a series of psychological tests and interviews.
The study’s authors concluded that the extra testosterone, when “administered to normal men in a controlled setting,” did not increase angry behavior.
By contrast, a 2008 study based on data from a nationwide, long-term study of adolescent health found that young adult men who self-reported use of anabolic steroids also reported greater involvement in violent behaviors.
Other research suggests that a small minority of performance-enhancing drug users — about 5 percent, according to Harvard University psychiatrist Harrison Pope, a specialist on the topic — may experience related psychiatric effects including mania, increased aggression, hypomania and depression, particularly when multiple types or extremely large doses of steroids are used.
Though researchers suspect that some individuals may be predisposed to adverse psychological reactions upon using performance-enhancing drugs, they have been unable to conclusively answer a basic question: Do steroids make people more violent and aggressive, or are violent, aggressive people more likely to use steroids?
Ryan Rodenberg, a lawyer and a sports management professor at Florida State University, said criminal defendants have used “roid rage” arguments with varying degrees of success, in part because the defense is not accepted in all jurisdictions.
In a 1988 case that received national attention, a 23-year-old competitive bodybuilder named Horace Williams was charged with murder in the brutal robbing and killing of a drifter in Florida. During Williams’ trial, his defense attorney argued that excessive steroid use had made his client insane on the night of the murder — so much so that hours before the killing, a raging Williams tore a convenience store pay phone from its metal stand after discovering it was out of order.
Unconvinced, a jury found Williams guilty of first-degree murder.
“Whether such defense is successful often turns on the testimony of the expert witnesses hired by both sides,” Mr. Rodenberg said.
Mr. Collins — a former competitive bodybuilder and author of “Legal Muscle: Anabolics in America” — said that a “roid rage” defense could have a greater impact on sentencing than on a verdict.
In June, the attorney for a Virginia man who pleaded guilty to second-degree murder in the death of his wife argued that steroid use and coffee addiction caused his client to have “diminished capacity” at the time of the killing.
A Franklin County Circuit Court judge sentenced the man to 40 years for the murder — but with 18 years suspended.
“I’ve seen situations where the consumption of steroids has been used to mitigate some criminal behavior,” Mr. Collins said. “Not as a complete defense, but a diminished sentence.
“I’ve seen it also used in the context of a quote-unquote addiction to help steer a convicted defendant toward rehabilitation as a focus of sentence. But every case has different facts, so every case needs to be assessed individually.”