Steroid use appears to have a more pronounced — and potentially dangerous — effect on male behavior when the drugs are administered during adolescence. That's the conclusion of a newly published study, which suggests that while professional athletes who use the performance-enhancing drugs may be doing themselves long-term harm, those at greatest risk may be the teenagers who follow their example.
In a series of experiments, a research team led by Kaliris Salas-Ramirez of Michigan State University directly compared the behavioral consequences of anabolic androgenic steroid exposure during adolescence and adulthood. The paper, published in the journal Behavioural Brain Research, described a study in which male Syrian hamsters were injected with either steroids or a placebo each day for two full weeks.
Half the group received the shots during their adolescence (27 to 41 days of age), while the others received them after growing into adults (63 to 77 days of age). At two weeks and again at four weeks after the injections were stopped, the hamsters' behavior was observed in terms of both mating and aggressiveness.
"An AAS cocktail, in doses comparable to what a heavy or chronic anabolic steroid human user would administer, led to reduced potential for sexual satiety that persisted at least four weeks beyond the exposure to AAS, whether subjects were treated in adolescence or adulthood," they researchers report. "Similarly, AAS resulted in persistent increases in aggressive behaviors and flank marking, regardless of the age at which exposure to AAS occurred." (Flank marking is a testosterone-modulated scent marking behavior that communicates dominance status between adult male Syrian hamsters.)
That's troublesome enough, but here's the key finding: When the hamsters administered steroids during adolescence were observed after four weeks, the researchers could not find a single incidence of submissive behaviors such as tail-up walking or escape dashes. In contrast, those administered the steroids during adulthood engaged in such behaviors at roughly the same rate as the control group.
This suggests that, in the important arena of sensing when it's time to turn tail (literally, in their case), the drugs had only a minimal effect on the adults, but a very large one on the still-developing brains of the adolescents.
Anabolic androgenic steroids are synthetic derivates of testosterone. According to the National Institute on Drug Abuse, they promote the growth of skeletal muscle and the development of male sexual characteristics in both males and females. There is some debate how widespread their use is among adolescents; while Salas-Ramirez and colleagues say it is "steadily increasing," the National Institute on Drug Abuse reports steroid abuse among teens seems to have peaked in 2000.
This new study indicates it's important to get an accurate handle on what's happening, since steroid use appears to have long-term behavioral as well as physical consequences — and adolescent brains seems to be more vulnerable than those of adults.
Are you on Facebook? Become our fan.
Follow us on Twitter.