Studies using animal models of adolescence have shown lasting consequences of adolescent exposure to alcohol, nicotine, and cannabinoids, including increases in later drug self-administration in some instances, along with alterations in cognitive and socioemotional functioning. In the case of alcohol, some evidence has also emerged for retention of immature, adolescent-typical alcohol sensitivities into adulthood. Neural alterations include relatively long-lasting changes in later neural functioning and gene expression in the neurocircuitry processing rewards, social and emotional stimuli, and cognition. Thus, although at this early stage, other aged exposure groups have not always been included to determine whether adolescence represents an especially vulnerable period, convincing data has nevertheless emerged that repeated exposure to drugs during adolescence often exerts relatively long-lasting alterations in later neurobehavioral function.