According to a U.S. Study, use of steroids by teenagers can have a long-term effect on their brains besides flipping the brain switch for aggression lasting as many as two years.

The involved researchers noted that anabolic steroids can cause permanent changes, a fact that was based on results experienced with hamsters.

It is worth noting here that neuroscientists have been showing great concern about the rising adolescent abuse of anabolic-androgenic steroids (AASs).

From News-Medical.Net::

According to the researchers even after the drug was withdrawn, the newly vicious hamsters attacked, bit and chased the intruders, and the level of aggressiveness was 10 times greater than that of other hamsters which were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.

Three weeks after withdrawal, vasopressin levels had subsided in line with the aggressive behaviour.

The study appeared in the present edition of Behavioral Neuroscience, Vol. 120, No. 1.