In addition, early adolescents become more aware of societal influences, and they become more like adults in their active consumption of cultural messages from the mass media and their peers. Studies have shown that third-graders tend to associate drinking alcohol with negative outcomes such as acting wild, rude, or silly, the investigators noted. By contrast, by age 10 most children have formed response-outcome expectancies about drinking alcohol that are more positive. Early adolescents are increasingly sensitive to peer behaviors, and the mass media could serve as a “superpeer” in forming their thinking, they said. Movies and television aimed at adolescents often show teenagers drinking and rarely show them suffering any negative consequences.
The biologic effects of puberty also have an impact on alcohol use in early adolescence, although the mechanism of these effects has not been well studied, Dr. Windle and associates noted. But data from multiple studies have shown that the changes that occur in the brain during early and middle adolescence include changes in neurocognitive functions (such as decision making and risk taking) that are linked to alcohol use.
“Family history of alcoholism, parents' drinking levels, perceptions of peer drinking, and prototypes of typical adolescent drinkers all seem to help shape expectancies,” the investigators wrote. But learning and personality factors play a role, too. It also must be understood that each human is an active agent in determining developmental pathways and that resilience (resistance to moving down problematic pathways) is as important to understand as are processes leading to maladaptation and disease,” they emphasized.
Alcohol-specific risk factors and protective factors have a significant impact at this age. Data from multiple prediction studies have shown that the number of alcohol-using friends can account for up to 50% of the variance in teen and preteen alcohol use. And parents and older siblings continue to influence adolescent alcohol use and contribute to alcohol expectancies that formed during early childhood. Protective factors that deter early adolescents from alcohol use include an affectionate temperament, high levels of religiosity, and nurturing, supportive parents, based on data from prospective studies.
By late adolescence, aged 16–20 years, alcohol use tends to escalate and youth are increasingly vulnerable to alcohol use problems and alcohol use disorders. The increased vulnerability stems from a combination of the ongoing early adolescent risk factors and the unique neurologic, social, and cognitive changes that occur in late adolescence, wrote Sandra A. Brown, Ph.D., of the University of California, San Diego, and her colleagues (Pediatrics 2008;121:S290-310).
“Adolescence is now realized as a period of continued neurologic development, and the adolescent brain may be especially vulnerable to the neurotoxic effects of alcohol, especially given the typical ways in which youths drink,” the investigators wrote.
Data from behavioral genetics research show that the genetic factors that can affect adolescent alcohol use appear to have greater impact during the transition from middle to late adolescence. In addition, genetic influences that have an impact on problem drinking appear to overlap with other disinhibited behaviors that are influenced by genetics. But that doesn't mean that genetics alone contribute to the tendency toward alcohol abuse in some adolescents and not others. In fact, more evidence suggests that genetic influences on such complex behaviors as problem drinking result from a mix of environmental and inherited factors, they noted.
Problems with alcohol in late adolescence have proven links not only to problem drinking but also to an increased risk for mental health problems and poor social function in adulthood. Findings from longitudinal studies of alcohol use enhance the developmental picture by showing how individuals and subgroups of adolescents differ in their patterns of alcohol use over time.
The trajectory groups most often used to characterize adolescent drinking patterns include abstainers/light stable moderate drinkers, fling drinkers, decreasers, chronic heavy drinkers, and late-onset heavy drinkers. The proportion of adolescents who fall within these groups varies among different studies, but in general the abstainers/light drinkers account for 20%–65% of the adolescent population, while stable moderate drinkers account for approximately 30%, fling drinkers and decreasers each account for approximately 10%, and chronic heavy drinkers and late-onset heavy drinkers each account for less than 10%.
Risk factors and protective factors associated with alcohol use and abuse in late adolescents have been well studied. Risk factors include a family history of alcoholism, history of mental health problems, and history of physical or sexual abuse. Protective factors include long-term educational or job goals and positive family and social relationships. The timing of other life transitions such as getting a job and getting married also can have an impact on alcohol use and abuse in late adolescence.