ATLANTA &

When news broke of the pro wrestler who killed his wife and son and hanged himself, one thought immediately crossed Dr. Linn Goldberg's mind:




"Check for steroids," said Goldberg, a sports medicine specialist at Oregon Health and Science University, recalling the moment.




Medical studies have looked at the behavioral effects of anabolic steroids only at limited doses, and they found only a small percentage of men became unusually aggressive. But some experts believe that steroids &

taken at excessive amounts &

can spark uncontrollable bursts of anger and even prolonged psychosis.




Steroids have been one focus of speculation in the story of Chris Benoit, the professional wrestler who last weekend strangled his wife and smothered his son before hanging himself on the cable of a weight-machine in his Atlanta-area home.




No clear motive has emerged for the killings, which were discovered Monday. But authorities noted steroids were found in the home. This week, federal drug agents raided the office of Dr. Phil Astin, a doctor who prescribed testosterone for Benoit.




Hours before the raid, Astin told The Associated Press he had treated Benoit for low testosterone levels, which he said likely originated from previous steroid use. Astin prescribed testosterone for Benoit, a longtime friend, in the past but would not say what, if any, medications he prescribed when Benoit visited his office last Friday.




Whether Benoit was taking steroids at the time of the slaying is yet to be established. Toxicology test results may not be available for weeks or even months, investigators said.




Officials with World Wrestling Entertainment, which employed Benoit, said the wrestler was last tested for steroids April 10, and the results were negative. A call placed to a WWE spokeswoman, asking for more details about the testing, was not returned Thursday.




Anabolic steroids are synthetic substances related to testosterone, the male sex hormone. They were developed in the 1930s to treat men who did not naturally produce enough testosterone for normal growth and sexual functioning.




But scientists discovered steroids could grow muscle in laboratory animals, and the chemicals caught on with bodybuilders, weightlifters and other athletes.




The National Institute on Drug Abuse warns of a range of harmful side effects from abusing anabolic steroids, including liver tumors and cancer, jaundice, high blood pressure, severe acne and trembling. In men, it also can cause shrinking of the testicles, reduced sperm count, infertility, baldness and increased risk of prostate cancer.




Many users report feeling good about themselves while on anabolic steroids, but some experts say abuse may lead to behavioral problems.




Some scientific studies have focused on the effects of about 100 milligrams of testosterone a week, as a replacement therapy for men who do not make enough testosterone. The effects were beneficial, both physically and psychologically, said Dr. Norm Mazer, director of a Boston University Medical Center research unit that focuses on steroids.




In studies using larger doses, of about 600 milligrams a week, only about — percent of subjects displayed unusual or manic behavior. No studies have been done using larger doses than that, Mazer said.




Some wrestlers and bodybuilders may take as many as 10,000 milligrams of steroids a week, Goldberg said.




Anecdotal case reports indicate extreme mood swings can occur at those levels, including manic-like symptoms leading to so-called 'roid rage' and violence.




The problem might be more acute in people who have underlying psychiatric conditions like bipolar disorder or manic depression. Aggression also can be exacerbated by alcohol or other drugs, Goldberg said.




In a statement, WWE officials said there's no reason to believe the Benoit killings were a result of roid rage.




"The physical findings announced by authorities indicate deliberation, not rage. The wife's feet and hands were bound and she was asphyxiated, not beaten to death. the account of the authorities, there were substantial periods of time between the death of the wife and the death of the son, again suggesting deliberate thought, not rage. The presence of a Bible by each (of the bodies) is also not an act of rage," according to a statement posted on the organization's Web site.




But there are other ways to interpret the crime scene, said Goldberg, who used to do Olympic athlete drug testing for the U.S. Anti-Doping Agency.




The placing of Bibles could indicate Benoit was in a prolonged psychotic state, out of touch with reality. There are case reports of psychosis in steroid abusers, Goldberg said.




"Bibles? That's bizarre. Did he think he was talking to God, and perhaps taking them to a higher level?" Goldberg wondered.