With one sports hero after another being accused of taking performance-enhancing steroids, it’s no surprise many teenage athletes decide to give it a try.

Health experts are deeply concerned about rising adolescent abuse of anabolic steroids. The National Institute on Drug Abuse estimates that half a million eighth- and tenth-grade students abuse steroids yearly. Not only do steroids set kids up for heavier use of steroids and other drugs later in life, but long-term users can suffer from mood swings, paranoia, acne and increased risk of heart and liver disease, stroke and cancer.

New research also shows that anabolic steroids not only make teens more aggressive, but also may keep them that way into young adulthood. The effect ultimately wears off, but there may be other lasting consequences for the developing brain.

Recent studies in the journal Behavioral Neuroscience showed that aggression rose and fell in synch with neurotransmitter levels in the brain’s aggression control region. Findings suggest that the aggressiveness triggered by steroids, although reversible, may last long enough to create serious behavioral problems for adults.

The studies were done in seventy-six adolescent hamsters. Because this part of the rodent and human nervous systems are similar, researchers generalized their findings to humans. Researchers observed how hamsters injected with common steroids became extremely aggressive, and the effect lingered for several weeks after the drug was withdrawn.

These new insights could lead to treatments for aggressive behavior, with or without steroid abuse, with certain neurotransmitters emerging as targets for drug therapy.