Oct. 22 (HealthDay News) -- Rats develop memory loss in adulthood after receiving high doses of amphetamines during their "teen" years, new research shows.
Exposure to the drugs during adolescence has a more severe impact on short-term memory than being exposed as adults, researchers found in a study that was to be presented this week at the Society for Neuroscience annual meeting, in Chicago.
"Animals that were given the amphetamine during the adolescent time period were worse at tasks requiring working memory than adult animals that were given the same amount of amphetamine as adults," study co-author and psychology professor Joshua Gulley of the University of Illinois at Urbana-Champaign, said in a school news release. "This tells us that their working memory capacity has been significantly altered by that pre-exposure to amphetamine."
The researchers gave amphetamines to rats in two ways: Some were given a steady dose every other day, while others were given more and more over four days, followed by a "binge" consisting of big doses every two hours for eight hours on day five.
The findings could indicate what might happen to teenagers who take amphetamines either as a recreational drug or to treat attention-deficit/hyperactivity disorder, the study authors suspect. But until more research is completed, it won't be clear whether the rat tests accurately indicate what happens in humans.
Gulley noted that the research in rats suggests that teens who take amphetamines recreationally may be at the most risk because their doses are higher than those who take them as prescribed by doctors.
"Adolescence is a time when the brain is continuing to develop into its mature form, so drug exposure during this critical period could have long-lasting, negative consequences," he said. "Our findings reveal that adolescents are particularly sensitive to the adverse effects of amphetamine on cognitive function and that these effects can persist well after drug use is discontinued."
SOURCE: University of Illinois at Urbana-Champaign, news release, Oct. 21, 2009