According to a U.S. study steroids may have a lasting effect on teenagers' brains, and could even flip the adolescent brain's switch for aggression which may last for at least two years.
The U.S. researchers also suggest anabolic steroids can cause permanent brain changes.
The study however was based on results seen in hamsters and some experts say on that basis it is impossible to estimate the length of effect in humans.
Neuroscientists are deeply concerned about the rising adolescent abuse of anabolic-androgenic steroids (AASs), given the National Institute on Drug Abuse's estimate that nearly half a million 8th to 10th-grade students abuse AASs each year.
Not only do steroids set kids up for heavier use of steroids and other drugs later in life, it is known that long-term steroid use can cause mood swings, hallucinations and paranoia, liver damage and high blood pressure, as well as increased risk of heart disease, stroke and some types of cancer.
Coming off steroids can also lead to depression.
The researchers at Northeastern University, Boston, examined the behaviour of adolescent hamsters when another hamster was put into their cage.
It seems that hamsters naturally defend their territory by play-fighting, wrestling and nibbling, but hamsters injected with commonly used steroids, which were suspended in oil, became extremely aggressive.
According to the researchers even after the drug was withdrawn, the newly vicious hamsters attacked, bit and chased the intruders, and the level of aggressiveness was 10 times greater than that of other hamsters which were only injected with oil.
Apparently the effects lasted for almost two weeks, which is the equivalent of half their adolescence.
After this period, the animals reverted to their normal playful defensiveness, but postmortems on the hamsters found there had been also been changes in their brain activity.
While they were being given steroids, a part of their brains called the anterior hypothalamus, which regulates aggression and social behaviour, pumped out more of a neurotransmitter called vasopressin.
Their full-blown aggression which was clearly drug-induced lasted for nearly two weeks of withdrawal.