CEDAR study’s longitudinal data reveal associations between sedentary adolescence, substance use, and the risk of cannabis use disorder in young adulthood

In this article, authors Tarter et al. cited existing research documenting that physical inactivity is associated with the genetic tendency to develop substance use disorders. In addition they noted that adolescents in the US are increasingly sedentary, while cannabis use disorder (CUD) is on the rise. (CUD is defined as a pattern of cannabis use that leads to clinically significant impairment or distress.) The authors theorized that increasing levels of physical inactivity and substance use frequency during adolescence, along with having parents with a substance use disorder, contribute to the development of CUD in young adulthood.

To investigate this theory, Tarter et al. used data from a large, longitudinal, multidisciplinary study that they led. Funded by the National Institute on Drug Abuse and distributed by the National Addiction & HIV Data Archive Program, the study is called the Center for Education and Drug Abuse Research (CEDAR): Etiological and Prospective Family Study in Southwestern Pennsylvania, Baseline and Follow-Up Data, 1990-2014 (ICPSR 33444). The goal of CEDAR was to better understand the causes of substance use disorders–from genetic risk factors to psychopathological, social and demographic ones. CEDAR collected data from 775 families that had a child between the age of 10 and 12. The sample included a group of 344 children with substance abusing fathers, and two control groups: 350 children with non-substance abusing fathers, and 81 children with fathers who had psychiatric disorders not related to substance abuse. These children were studied for a 20-year period, starting with a baseline evaluation in 1990, then at age 12-14, age 16, age 19, age 22, age 25, age 27, and age 30 in 2014.

For this paper, Tarter et al. analyzed physical activity and substance use data from 462 male and 178 female CEDAR participants tracked through the age 22 follow-up. The authors were able to demonstrate that when parents have a substance use disorder, it can predict how much their children will become physically inactive as they grow from ages 10 to 22. Additionally, the study found that the rate at which physical inactivity increases in adolescence is linked to how often adolescents use substances, which increases their risk for CUD. They also noted that since cannabis with higher concentrations of THC is increasingly available, it’s more important than ever that youth are physically active. Physical exercise reduces “the severity of the cognitive, emotion[al], and behavioral disturbances resulting from suboptimal executive capacity” that is associated with using cannabis, leading to reduced cannabis craving as well as “improved treatment prognosis in problem cannabis users.” Finally, with this longitudinal study design, the authors confirmed prior research showing an association between physical inactivity and substance use, and extended it by finding that “physical inactivity comprises a component of CUD vulnerability which, at least in males, is intergenerationally transmissible.”