A new study investigated associations between the use of cigarettes, alternative tobacco products (e.g., cigars/cigarillos, hookah, e-cigarettes), alcohol, and marijuana within the college population. Participants were 3,418 U.S. undergraduate students who completed an online survey about their substance use behaviors, as well as the substance use behaviors of their parents, siblings, and five closest friends within the past 30 days and past four months. The researchers used a structural equation model (SEM) approach to determine the effects of parent, friend, and sibling use on participants’ own use. Results showed that the prevalence of past 30-day use of alcohol was 63.5%, past 30-day use of marijuana was 19.7%, and past 30-day use of most tobacco products was about 13%; however, cigar use ranged from 8.4% – 11.3%, depending on the type of cigar. For alcohol and tobacco products, the odds of college students using a particular substance roughly doubled if either parents or siblings used it. For marijuana, these odds more than tripled. The odds of college students using alcohol and tobacco products were six to nine times greater if friends used these substances. The odds of students using marijuana were over 21.0 times greater if their friends used it.
Take away: For college students, friends (and, to a lesser degree, siblings) may significantly influence substance use behaviors. This relationship is true for alternative tobacco products, tobacco products, alcohol, and marijuana.