Unlike most illicit drug use, misuse of anabolic steroids most commonly begins in young adulthood rather than adolescence. But steroid use in teens is of concern, especially since the hormonal systems they interact with play a critical role in brain development during these years.92–96 In adolescent rodents, exposure to anabolic steroids increased neuronal spine densities in the hippocampus and amygdala—brain regions involved in learning and emotions (e.g., aggression), respectively. Four weeks after withdrawal, these increases in neuronal spine densities returned to normal in the amygdala, but not in the hippocampus. This suggests that pubertal steroid exposure could produce long-lasting structural changes in certain brain regions.97
Teens who use anabolic steroids may also be at increased risk for some cognitive side effects compared with adults. For example, males who begin using anabolic steroids during the teen years show increased impulsivity and decreased attention, compared to men who began using steroids in their adult years.98 In adolescent rats, anabolic steroid exposure is associated with electrolytic imbalances, hyperactivity, anxiety, and increased sympathetic autonomic modulation (e.g., fight or flight response) during adulthood, even when steroid use was discontinued during adolescence.99 In addition, adolescent male hamsters given anabolic steroids show increased aggression, even after steroid use is discontinued. These aggressive effects are paralleled by changes in levels of serotonin 100,101 and androgen receptors in the rodent brain.102