Reciprocal Associations Between Cannabis Use and Exercise and Sleep During Early Adolescence

Prior research indicates potential reciprocal relationships between cannabis use and both exercise and sleep duration in older adolescents and adults, though findings on the direction of these associations are inconsistent. No study to date has simultaneously examined these reciprocal relationships among a large, early adolescent sample. This paper examines the reciprocal associations between cannabis use and physical exercise, strength exercise, and sleep duration during early adolescence, with age and sex differences. We analyzed youth-reported cannabis use, physical and strength exercise, and sleep duration in 9 to 15 year-old adolescents enrolled in the longitudinal Adolescent Brain and Cognitive Development (ABCD) Study (N=11,868). Multilevel regression models, parsing between- and within-youth associations were fit to examine the association between cannabis use and three outcomes–physical exercise, strength exercise, and sleep duration–both concurrently and prospectively. Age and sex moderations between cannabis use and physical health outcomes were tested. In the main effects analysis, robust reciprocal associations emerged between cannabis use and strength exercise and sleep, both concurrently and prospectively. Age moderated the association between cannabis use and sleep duration (β = -0.0024, p = .03): more cannabis use was associated with longer sleep duration in younger adolescents (<=11.7 years old), whereas more cannabis use was associated with shorter sleep duration for older youth (>=11.7 years old). Sex moderated the exercise associations: female youth engaging in more physical exercise reported less cannabis use (β = -0.3526, p = .004) compared to males. In a nationwide sample of adolescents ages 9 to 15 years-old, we found strength exercise and sleep duration to be most strongly and reciprocally associated with cannabis use concurrently and prospectively. Adequate sleep duration may be an important protective factor against cannabis use for older youth. Exercise in general may also serve as a protective factor against early cannabis use, more so for females than males, and physical exercise may be more protective of later cannabis use compared to strength exercise.