TORONTO - Super high doses of anabolic steroids appear to effectively change the chemistry of the brain, ramping up aggression while dialling down impulse control features, experts say.
The changes, which in some animal studies seem to be permanent, can lead to both outbursts of intense, over-the-top aggression -- known by the nickname 'roid rage -- and a withdrawal type depression that can also be dangerous for both the drug user and potentially people around them, some who research the drugs say.
The issue of 'roid rage has come to the fore as a possible explanation for the murder-suicide of professional wrestler Chris Benoit, who killed his wife and young son before hanging himself. The carnage was discovered in the wrestler's home in Georgia on Monday.
Anabolic steroids were found in Benoit's home. However, results of tests to see if the wrestler had been using the drugs are not expected to be available for some time.
One scientist who studies the impact of steroids in animals describes the effect as simultaneously slamming down the gas pedal -- the aggression circuitry -- while completely releasing the brake -- the brain's impulse control system.
"You're accelerating with no governing," says Richard Melloni, a specialist in behavioural neuroscience at Boston's Northeastern University.
"The circuits that are driving the behaviour are becoming pushed and those that are stopping the behaviour are not being pushed."
It's known steroids are often used in power sports like professional wrestling, where the need for an intimidating physique can lead to reliance on drugs that both spur development of muscle and allow for quicker recovery after a workout. Those features of the drugs allow people who use them to build more muscle more quickly.
Essentially synthetic versions of the hormone testosterone, they are used at levels 10, 100, even 1,000 times what would normally course through the human body.
While they help build muscle, the drugs take a toll -- both physically and on the mental health of users.
One consequence can be premature heart disease. When wrestler Davey Boy Smith, a.k.a. the British Bulldog, died in 2002 at the age of 39, it was suggested his past use of anabolic steroids may have played a role in his death.
And the drugs have been linked to suicide -- a possible consequence on the inhibiting role they exert over serotonin, a brain chemical that modulates mood.
But it is the ratchetting up of aggressive tendencies that is the best known side-effect of steroids -- the uncontrolled, intense outbursts in reaction to events that would trigger a more contained response in a non-steroid user.
"That's what 'roid rage is," Melloni says. "It's a very impulsive, episodic event characterized by very high and intense levels of violence."
He points to the case of a body builder who was incensed that a car in front of him didn't take off quickly enough after a traffic light turned green. The body builder yelled at the driver, who yelled back. The body builder then went back to his vehicle, grabbed a baseball bat from the trunk and smashed in the offending car's headlights and windshield.
The bat-wielding body builder was dragging the driver out of the vehicle when police arrived and arrested him.
"We think of 'roid rage as `Punch you once and that's over.' Well, that's not what it is," Melloni says from Boston.
There's no evidence Benoit's actions were steroid-induced. World Wrestling Entertainment, for instance, issued a statement that there was a premeditation to the killings that suggests otherwise.
Dr. Linn Goldberg, head of the division of health promotion and sports medicine at Oregon Health Sciences University, says in his experience, people who suffer 'roid rage type outbursts are people who have an underlying problem with aggression control.
"If you're a docile, loving, caring individual who's not violent, it's not going to be a Dr. Jekyll and Mr. Hyde (effect)," Goldberg, whose research focuses on programs designed to deter athletes from using steroids, said from Portland, Ore.
"They come to this with a history of maladapting to society or living on the edge or very aggressive behaviour beyond that of law abiding citizens. It doesn't happen just to out of the blue."
Melloni disagrees.
His work, in hamsters, shows that about 85 per cent of these normally placid animals become aggressive after being dosed with steroids at rates comparable to what humans use, but adjusted for differences in body weight.
Because it would be unethical to experimentally inject people with steroids, animal studies are about the best evidence science can muster on the effects of high doses of steroids.
Melloni says one can't predict from the pre-steroid behaviour of the animals which will become the most aggressive. "The ones that are more dominant don't always turn out to be the ones that are more aggressive."
