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Family Dynamics

A Study on Siblings and Alcohol Use Disorder

Does one sibling's alcohol use affect another's? Yes and No.

Key points

  • Adolescence is a key period for studying the effects of drinking among siblings.
  • Not surprisingly, siblings' relationships with each other affected their drinking.
  • The first year of college is critical when it comes to drinking, especially related to sibling drinking.

A research study on siblings and alcoholic use disorder, The Development Unfolding of Sibling Influences on Alcohol Use Over Time, is worth noting. The researchers, who included professors and a graduate student at Auburn University, along with a professor at The University of Minnesota, found that earlier research has shown siblings are similar in alcohol and substance use, or “partners in crime.” However, these researchers found that older siblings’ use of alcohol may predict younger siblings’ alcohol use, but younger siblings' use only predicted an older sibling’s use if they were close in age and had a close relationship. (Note: The siblings studied were a maximum of five years apart, and adopted children were included as well as biological children.)

The researchers concluded that their findings may have ramifications for treatment programs and individual therapy for a sibling who drinks to excess. “There is little attention to siblings in programs aimed to reduce adolescent alcohol or substance use,” one explains, adding that their results “add to a body of literature illustrating how both older and younger siblings are important socializing agents of adolescent and early adult alcohol use.” Moreover, “younger siblings may be just as important socializing agents of their older siblings’ alcohol use.” Thus, “assessing or co-treating siblings for alcohol problems may be an important add-on to existing alcohol prevention and intervention programs,” researchers noted, and at the very least, the programs might consider “assessing sibling alcohol use, relationship quality, as well as facilitation of or co-use.”

Researchers also posited that adolescence is a particularly important span for study because if two siblings have a close relationship and neither drinks to excess, it could have a protective effect when the younger one reaches college. But if the older one drinks to excess, then that may negatively affect the younger one when it comes to drinking, especially in the freshman year.” The researchers defined the adolescent age ranges important to the study as early adolescence, ages 13 to16, and late adolescence as ages 17–19. They described early adulthood as ages 21–23.

The group cites one limitation of their study, it included mostly White or Asian subjects. It would be interesting to learn what a study that included Blacks would find, and also why the researchers didn’t include this ethnicity. Also, information on gender differences and similarities related to drinking was briefly referred to, from other studies.

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