McGue, M., Iacono, W.G., Legrand, L.N., Malone, S., & .Elkins, I. (2001, August). Origins and consequences of age at first drink. I. Associations with substance-use disorders, disinhibitory behavior and psychopathology, and P3 amplitude. Alcoholism: Clinical and Experimental Research, 25(8), 1156-1165.
McGue, M., Iacono, W.G., Legrand, L.N., & Elkins, I. (2001, August). Origins and consequences of age at first drink. II. Familial risk and heritability. Alcoholism: Clinical and Experimental Research, 25(8), 1166-1173.
Previous research has shown that individuals who have their first drink of alcohol before the age of 15 are substantially more likely to become alcoholic than those who have their first drink after the age of 20. This has led to the assumption that an early age at first drink (AFD) is a direct risk factor for alcoholism, and that delaying AFD will directly decrease the risk for later problems with alcohol. Two studies in the August issue of Alcoholism: Clinical & Experimental Research question this assumption. Researchers found that an early AFD is not necessarily specific to alcoholism but is one of several behaviors that make up a more general, underlying problem of behavioral undercontrol.
"It has been thought that an early drink increased alcoholism rates by disrupting ‘normal’ developmental processes in adolescence," explained Matt McGue, a professor in the department of psychology at the University of Minnesota, and lead author of both studies. "Our finding – that early use of alcohol is not specifically associated with increased rates of alcoholism, but is also predictive of increased rates of other drug abuse/dependence, mental health problems, and educational underachievement – is not necessarily inconsistent with this hypothesis. However, our results indicate that problems seen in adulthood among early drinkers existed prior to their taking that first drink, which suggests that developmental processes were already disrupted prior to that first drink. Thus, an early AFD is more likely a symptom of an underlying vulnerability of disinhibitory processes rather than a cause of increased rates of alcoholism."
What psychologists and psychiatrists refer to as ‘disinhibitory processes’ is the inability or unwillingness to inhibit behavioral impulses even in the face of negative consequences. Some of the specific behaviors that McGue and his colleagues found to be associated with an early AFD were nicotine dependence, illicit drug use and dependence, antisocial personality and conduct disorder, low school achievement, low behavioral constraint (people with low constraint act impulsively, caring little about adhering to societal norms), and a reduced P3 amplitude (a well-known psychophysiological marker of alcoholism risk). The researchers also examined the data – drawn from the federally funded Minnesota Twin Family Study – to see if an early AFD might reflect a genetic risk for disinhibitory behaviors. They found that the sons (but not the daughters) of parents with an early AFD were themselves at increased risk for conduct and oppositional defiant disorder. They also found that early use of alcohol is familial and, at least among males, can be inherited.
"It is well established that early AFD is associated with alcoholism and/or problem drinking," said Carol A. Prescott, a psychologist and associate professor of psychiatry at the Virginia Commonwealth University. "Yet this and other research indicate that early AFD is also associated with other problem outcomes. This will not be a surprise to alcohol researchers and other readers. The controversial aspect is in the interpretation of such findings for alcoholism prevention." Prescott said that AFD has been identified as a target behavior by some prevention efforts that seek to increase by one year the average age for AFD among U.S. adolescents. This would, theoretically, decrease the risk for later developing alcohol problems.
"These findings, however, question that assumption," said Prescott. "The results suggest that AFD is correlated with problematic alcohol use, but not necessarily causal. This research builds upon earlier studies of adolescence which found that measures of ‘problem behavior’ predated alcohol use and differentiated adolescents who would later have alcohol problems." Prescott noted that the "causal" association between AFD and alcoholism more often came from members of the press rather than from the authors of the original studies.
"It would be useful," she added, "to have outcome studies, with appropriate control groups, to test empirically whether prevention efforts to delay AFD are effective in reducing problematic alcohol involvement as well as other possible correlated behaviors." Prescott said that other goals – such as decreasing the proportion of adolescents who proceed to regular drinking at an early age – might be more effective targets at which to aim efforts.
"If drinking early is a cause of increased rates of alcoholism," concluded McGue, "then we could help to prevent adult alcoholism by getting kids to delay the age at which they first drank. Unfortunately, I don't think that preventing alcoholism will be as easy as that. If early drinking is really a symptom rather than a cause, then ameliorating the symptom will have little impact on rates of alcoholism." He noted that even if adolescent alcohol use does not cause alcoholism, its prevention is a worthy goal for many other reasons, such as its role in automobile accidents and sexual victimization. "The bottom line," he said, "is that prevention efforts may need to target a subset of youth who are at increased risk for a wide range of behavioral problems in addition to problems with alcohol."