Your brain on steroids: A bigger problem than we know

During the Olympic Games, the world gazes admiringly upon athletes with preternatural musculature and athletic ability — and then laments every tainted urine test, every revelation of doping. In the mind of the public, this is the problem with anabolic steroids: They undermine fairness in competition between elite athletes.

Damaging the spirit of sport, however, is a minor concern compared with how anabolic steroids impair the health of those who use them — not only Olympians and professional athletes, but also high school football players and rank-and-file weightlifters.

Last month, as more than 100 Russian athletes were banned from Olympic competition for doping, federal investigators revealed that Omar Mateen, who killed 49 people at an Orlando nightclub on June 12, had a long history of steroid use. That detail had a chilling echo: Norwegian killer Anders Breivik deliberately used steroids to fuel his 2011 attack that killed 77 and injured hundreds. It received little attention in the U.S. news media, but Breivik methodically experimented with the drugs and, as documented in his diary, carefully selected the steroid and dose for his "mission."

These killings should tell us that even the direst health warnings about steroids — damage to the heart, liver and reproductive system — don't go far enough. It's what anabolic steroids do to the brain that can be truly terrifying.

The popular image of " 'roid rage" is a sudden and exaggerated response to a minimal provocation, like "The Incredible Hulk." But that's not how it works. Instead, studies in animals show that steroid-induced aggression is not impulsive, nor uncontrolled. Steroid-treated rats remain attuned to the context of the fight: who their opponent is and where the fight takes place. This suggests that anabolic steroids can promote not only spur-of-the-moment aggression, but also premeditated violence.

Some background information on anabolic steroids may prove useful. Steroids are organic molecules with rings that resemble chicken wire. "Anabolic" refers to their muscle-building properties. (Not all steroids are anabolic; cortisol is a steroid widely prescribed as an anti-inflammatory agent.) Despite a variety of pharmaceutical names — such as nandrolone, boldenone or dianabol — all anabolic steroids are derivatives of testosterone, the major steroid produced by the testes in men. At normal levels, testosterone builds muscle and contributes to characteristic "masculine" behavior. Anabolic steroid users may boost their testosterone up to 100 times normal levels.

In 2011, testosterone was the most-common banned substance found in urine tests administered by the World Anti-Doping Agency. It remains a popular choice for doping by elite athletes because it is challenging to distinguish injected testosterone from naturally occurring sources.

It is estimated that as many as 3 million Americans have availed themselves of these outlets — far more than most people realize. Anabolic steroids are in high schools, fitness centers and "rejuvenation" clinics. A typical user is a young man in his late teens or early 20s. Among U.S. high school students, 4 percent to 6 percent of boys have used anabolic steroids, comparable to the rates of crack cocaine or heroin use. Among men in their 20s, that rate is even higher.

Anabolic steroid users may be loath to admit it, but for most the drugs are just a shortcut to bigger muscles. Still, some people defend their use as a "healthy lifestyle choice" that allows them to work out harder and recover faster.

My own research on the effects of anabolic steroids on the brain and behavior shows that there's nothing healthy about it. Many anabolic steroid users show signs of addiction: They take more than intended and are reluctant to quit because of withdrawal symptoms and loss of muscle mass. In addition, heightened testosterone levels give users a sense of invulnerability and increase their risk-taking. The resulting behavior can endanger themselves and others: fighting, unsafe sex, drinking and driving, carrying a weapon. A Swedish study of anabolic steroid users showed high rates of death from homicide, suicide and drug overdose.

Research into these behavioral changes was slow to accumulate because steroid use became prevalent only in the late 1980s. Though anabolic steroid abuse remains understudied, today there is real evidence of the risks from surveys of current users and clinical studies of volunteers, supplemented with research in animals. So instead of just worrying about doped athletes during each Olympic cycle, we should focus on how widespread the use of anabolic steroids is and how dangerous they are for any users — and even those around them.