Impact of Amphetamine Exposure During Adolescence on Neurobehavioral Endpoints

Abstract

The recognition of the adolescent period as a time of increased drug use and potential vulnerability to the neurobehavioral effects of repeated drug use has existed for many years. Although clinical uses of amphetamines exist for adolescents, most notably for Attention-Deficit/Hyperactivity Disorder, the repeated recreational or illicit use of amphetamines during this time period has implications for long-term brain and behavioral development. During the adolescent period, monoamine neurotransmitter systems (particularly dopamine, norepinephrine, and serotonin) undergo continued development, and evidence from experimental animal models suggests that repeated use of amphetamines during this time can impact behavioral processes that rely on monoamine systems throughout the lifespan. Cognitive flexibility, a measure of prefrontal function, can be probed through the use of behavioral procedures, such as reversal learning and extradimensional shifting. A number of studies implicate prefrontal cortex function following repeated use of amphetamines (and other psychomotor stimulants) during the adolescent period. Further, evidence suggests that adolescent amphetamine exposure alters monoamine signaling and increases sensitivity to drugs that act on dopamine, norepinephrine, and serotonin later in life.