Adolescence represents a time of physical change and psychosocial stressors with an increased incidence of risk-seeking tendencies. Notably, adolescence is characterized as a critical window of neurological development. This maturation of neurocircuitry combined with risk-seeking tendencies results in a period of vulnerability to harmful factors such as drugs of abuse, or even chronic stress. The increasing availability, over-prescription, and subsequent misuse/abuse of ADHD-psychostimulant medications, such as dextroamphetamine (Adderall®) or methylphenidate (Ritalin®), in adolescent populations, necessitates studies investigating the long-term effects of these drugs. C57Bl/6J-mice were exposed to 1.0 mg/kg amphetamine (AMPH) or methylphenidate (MPD) from postnatal days 42-51 (late adolescence). After postnatal day 90, adult mice were challenged with a subacute methamphetamine (METH) dose (0.5 mg/kg). To test the long-term effects of adolescent drug exposures, animal activity was assessed using an open field chamber. Increased open field activity is a common measurement of behavioral sensitization, which is a hallmark of addiction. Late adolescent AMPH (male) and MPD (male and female) exposures induced cross-sensitization to METH in adulthood suggesting a sex-specific increased susceptibility to substance use. Unlike previous early adolescence studies, late-adolescent saline control treatments also induced adult cross-sensitization to METH. To isolate the hypothesized effects of the drug dosing induced stress, additional controls were included. Preliminary data suggest that adolescent stress produces a synergistic effect to drug exposure with adult addiction susceptibility. This study demonstrates differential drug-, sex-, and development-specific alterations induced by adolescent psychostimulant exposure and stress, leading to detrimental behavioral alterations toward drug abuse that persist into adulthood.
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