The study, available now online in advance of print in the journal Alcoholism: Clinical and Experimental Research, involved 597 Finnish twins — 300 male and 297 female — who were assessed at ages 18 and 25.
“The key finding was that the more drinking-related problems experienced by an adolescent at age 18, the greater the likelihood that adolescent would be diagnosed with alcoholism seven years later at age 25,” said Richard Rose, professor emeritus at IU’s Department of Psychological and Brain Sciences and senior author of the article. “That predictive association was stronger in females than males. The analysis of co-twins ruled out factors such as parental drinking and household atmosphere as the source of the association, because twins jointly experience these.”
Rose and his colleagues used the Rutgers Alcohol Problem Index (RAPI) to assess the twins at age 18. Seven years later they interviewed the twins using the Semi-Structured Assessment of the Genetics of Alcoholism to determine any alcohol abuse and dependent diagnoses.
RAPI is widely used to assess adolescent drinking-related problems, but this is the first time its predictive powers have been examined on a longitudinal basis. Rose said the findings have important implications for clinicians.
“The first step in intervention is to identify those at elevated risk,” he said. “Screening for drinking-related problems in adolescence may reliably identify many of those at elevated risk for development of alcoholism, and a self-report instrument such as RAPI offers an efficient approach for such screening.”
More about the study:
- RAPI is a self-report questionnaire on the frequency with which an adolescent has experienced 23 consequences of drinking alcohol, such as getting into a fight with a friend or family member, in the preceding 18 months.
- More drinking-related problems experienced at age 18 were associated with a diagnosis of alcohol dependence at age 25.
- The researchers were surprised by the strength of the association between RAPI scores and later alcohol dependence, in females as well as in males, and in co-twins who differ in drinking but share their childhood environments and half or all of their segregating genes
- Researchers found that some study participants with high RAPI scores did not become alcohol dependent and conversely some with low scores did, opening the door for further research.
Rather than reflecting a direct cause-and-effect relationship between adolescent drinking and adult alcoholism, the study findings, say some researchers, indicate the possibility that individuals who transgress social norms in adolescence by drinking heavily may be those same individuals who transgress social norms in adulthood by drinking abusively.
“I would say for sure that heavy drinking in adolescence is a real danger sign, regardless of whatever the causal mechanisms are,” said Matt McGue, professor in the Department of Psychology at the University of Minnesota. “Heavy drinking in adolescence is an indication that preventive intervention is warranted.”
For a copy of the study, contact Mary Newcomb at mnewcomb-[email protected].
The study was funded by the National Institute on Alcohol Abuse and Alcoholism.
Co-authors of “Rutgers Alcohol Problem Index Scores at Age 18 Predict Alcohol Dependence Diagnoses Seven Years Later,” are Danielle M. Dick of Virginia Commonwealth University; Fazil Aliev of Virginia Commonwealth University and Ankara University, Turkey; Richard Viken of Indiana University; and Jaakko Kaprio of the University of Helsinki, and the National Public Health Institute, Finland.
Rose can be reached at 812-855-8770 and [email protected]. The Department of Psychological and Brain Sciences is in IU’s College of Arts and Sciences. McGue can be reached at 612-625-8305 and [email protected]. For additional assistance, contact Tracy James at 812-855-0084 and [email protected].