Anabolic steroid users may behave aggressively for a long time after stopping the drug, but the behavior -- and some of the brain changes linked to it -- may be reversible, animal research suggests.
In an experiment with teenage hamsters given anabolic steroids, scientists found that the animals continued to chase and bite their brethren for days during withdrawal from the muscle-building hormones.
At the same time, activity in the brain's vasopressin system, which is linked to aggression, was elevated in the steroid-treated hamsters.
After a couple weeks, however, both vasopressin activity and aggression subsided -- suggesting, the researchers say, that teenagers' use of anabolic steroids may have lasting but reversible effects on behavior and the vasopressin system.
But that doesn't mean that anabolic steroids aren't so bad after all, stressed lead study author Dr. Richard H. Melloni Jr. of Northeastern University in Boston.
"The promising part of the study is that it suggests (the aggression) will go away over time," he told Reuters Health. But the "disturbing part," he added, is that it could take a good while.
The hamsters Melloni's team studied went back to normal by day 19 of steroid withdrawal, according to findings published in the journal Behavioral Neuroscience. In human teenagers, that could translate to more than two years.
What's more, although the hamsters' vasopressin systems also went back to normal, Melloni said he and his colleagues have evidence from separate research that other brain systems affected by steroids may not recover.
Namely, he explained, steroid abuse may hinder the development of the serotonin system, which suppresses aggression. So at a time when the young brain is still taking shape, teenage steroid users may enhance the development of the brain's aggression center while suppressing the maturation of its calming center.
In the latter case, the damage might be permanent, Melloni said. He noted that depression, which involves serotonin deficits, is a common problem seen during steroid withdrawal.
Melloni said he hopes research like this gets the message out that anabolic steroids affect not only muscle and performance, but the brain and behavior as well.
Many teenagers may be focused on getting stronger or running faster, he said, "but is that worth changing the development of your brain?"