The adolescent period is associated with high significance of interactions with peers, high frequency of stressful situations, and high rates of alcohol use. At least two desired effects of alcohol that may contribute to heavy and problematic drinking during adolescence are its abilities to both facilitate interactions with peers and to alleviate anxiety, perhaps especially anxiety seen in social contexts.
Ethanol-induced social facilitation can be seen using a simple model of adolescence in the rat, with normal adolescents, but not their more mature counterparts, demonstrating this
ethanol-related social facilitation. Prior repeated stress induces expression of
ethanol-induced social facilitation in adults and further enhances socially facilitating effects of
ethanol among adolescent rats. In contrast, under normal circumstances, adolescent rats are less sensitive than adults to the social inhibition induced by higher
ethanol doses and are insensitive to the socially
anxiolytic effects of
ethanol. Sensitivity to the socially
anxiolytic effects of
ethanol can be modified by prior stress or
ethanol exposure at both ages. Shortly following repeated restraint or
ethanol exposure, adolescents exhibit social anxiety-like behavior, indexed by reduced social preference, and enhanced sensitivity to the socially
anxiolytic effects of
ethanol, indexed through
ethanol-associated reinstatement of social preference in these adolescents. Repeated restraint, but not repeated
ethanol, induces similar effects in adults as well, eliciting social anxiety-like behavior and increasing their sensitivity to the socially
anxiolytic effects of acute
ethanol; the stressor also decreases sensitivity of adults to
ethanol-induced social inhibition. The persisting consequences of early adolescent
ethanol exposure differ from its immediate consequences, with males exposed early in adolescence, but not females or those exposed later in adolescence, showing social anxiety-like behavior when tested in adulthood. Adult males exposed to
ethanol early in adolescence also show enhanced sensitivity to the socially facilitating effects of
ethanol, whereas adult males exposed to
ethanol during late adolescence demonstrate insensitivity to the socially suppressing effects of
ethanol. To the extent that these results are applicable to humans, stressful live events may make alcohol more attractive for stressed adolescents and adults due to its socially facilitating and socially
anxiolytic properties, therefore fostering high levels of drinking. Retention of adolescent-typical responsiveness to alcohol in adult males following adolescent alcohol exposure, including enhanced sensitivity to the socially facilitating effects of
ethanol following early exposure and insensitivity to the socially inhibiting effects following late adolescent exposure, may put these males at risk for the development of
alcohol-related disorders later in life.