Common Alcohol Use Trajectories

by National Institute of Health

(Page 2 of 4)

Taxonomy Approaches: Identifying Multiple Trajectories

An alternative research approach is to identify distinct, homogeneous subgroups of people whose alcohol use trajectories during the transition to adulthood differ from one another. These different trajectories may have different antecedents and consequences and may therefore require different theoretical explanations and approaches to prevention and health promotion.

In the related domain of antisocial behavior, Moffitt proposed a dual taxonomy distinguishing between adolescence-limited and life-course-persistent antisocial behavior. Both types of antisocial behavior involve more delinquent and criminal behavior in adolescence, but the former group only engages in antisocial behavior during adolescence, whereas the latter, much smaller life-course-persistent group becomes involved in antisocial behavior earlier and continues it longer. It is hypothesized that the causes, meaning, and consequences of the behaviors differ markedly between the groups.

Taxonomies also have been proposed for types of adult alcoholism. For example, early alcohol research distinguished early-onset, antisocial alcoholism from later-onset, primary alcoholism. Zucker proposed a more developmental approach, taking into account the antecedents, course, and outcomes of alcohol problems. He identified four subgroups: Antisocial Alcoholism, Developmentally Cumulative Alcoholism, Developmentally Limited Alcoholism (time-limited, peer-focused heavy drinking and spontaneous reduction with the successful assumption of family and career roles), and Negative Affect Alcoholism (the use of alcohol to modulate negative mood, characterized by later onset).

Longitudinal studies that track people's alcohol use across multiple occasions from adolescence to adulthood also have identified taxonomies of young people with different trajectories of heavy alcohol use2 (see the figure). (2 Various analytic techniques are used to identify trajectory groups, ranging from cluster analysis to growth mixture modeling. Discussion of these techniques is beyond the scope of this article.) Some studies have spanned a broad age range, from early adolescence into the twenties. Others have focused on subsets of this time period, either examining the subjects' adolescent years up to age 18 or beginning in the subjects' late adolescence (e.g., prior to or just after high school) and following them into or through their twenties. Studies also differ in the indicators of alcohol use considered (e.g., frequency of drinking, quantity consumed, frequency of heavy drinking,3 or alcohol-related consequences) and the types of samples included (e.g., nationally representative school-based and household samples, longitudinal followups of samples used in prevention studies, or high-risk samples). (3 This article defines heavy drinking in general as consuming several drinks per occasion; often in the literature, this pattern of alcohol use is viewed more specifically as binge drinking, in which a person drinks five or more drinks on a single occasion.) Despite these important methodological differences, and some differences in findings, consistent patterns have been identified.

In research involving adolescents and young adults, the most common trajectory subgroup observed across studies contains abstainers, light drinkers, or very rare heavy drinkers across all time periods measured. Depending on definitions for these levels of alcohol consumption used in different studies, estimates of the proportion of young people in this low-risk group range from about one-fifth to over two-thirds. Members of another common trajectory subgroup, stable-moderate drinkers, engage in some heavy drinking across adolescence and young adulthood but do not escalate or decelerate their use dramatically. Across studies, estimates are that about one-third of adolescents and emerging adults into the mid-twenties fall into this group. Together, these two broad categories - which comprise relatively low-risk drinkers - include a large proportion of all young people.

Many studies involving adolescents and young adults also have identified groups of chronic heavy drinkers and late-onset heavy drinkers. These groups are distinguished by the age when the subjects started heavy drinking, but as this age varies from study to study, chronic heavy drinkers and late-onset heavy drinkers are more difficult to identify or compare across studies. Those who are designated as chronic heavy drinkers typically start heavy drinking at younger ages, by middle adolescence (early onset), and tend not to decrease their drinking in their twenties. Members of the late-onset heavy-drinking subgroup start to drink later (i.e., middle to late high school) than stable-moderate and chronic heavy drinkers, but their use escalates steeply.

"Fling" drinkers, who make up 10 percent to 12 percent of the adolescent and young adult population, take yet a different trajectory. They experience a period of developmentally limited heavy drinking that peaks and then declines following late adolescence or the early adult years.

A final subgroup, decreasers, appears to be more common in older adolescent and young adulthood samples than in younger samples. Decreasers begin heavy drinking at an early age, such as in middle school, but reduce their consumption significantly during high school. About 10 percent of adolescents and young adults fall into this subgroup.

Although researchers are beginning to understand what causes different people to follow these different trajectories, the applied and clinical significance of these pathways, while intriguing, has received little attention. For example, universal school-based prevention programs that target the majority of early adolescents not engaging in any heavy drinking may be less successful with adolescents who are on early-onset trajectories.

About the Author

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