Marijuana use by adolescents, including self-reported chronic use, is not associated with adverse health effects later in life, according to an assessment of longitudinal data published in the journal Psychology of Addictive Behaviors.
Investigators from the Pittsburgh School of Medicine and Rutgers University prospectively examined whether young men who consumed cannabis during adolescence and/or young adulthood experienced a heightened risk of developing physical and mental health problems in their mid-30s. Researchers controlled for several potential confounding factors, including subjects’ socioeconomic status, co-occurring use of alcohol, tobacco, and other drugs, and access to medical care and health insurance.
Researchers reported that marijuana users, including chronic users, were no more likely to self-report experiencing physical or mental health issues than were non-users. Investigators further reported that early onset chronic marijuana use was not associated with an increased risk for the development of depression or anxiety disorders in early adulthood.
The findings contradicted researchers’ initial hypothesis, as their stated motivation for conducting the study was to “provide empirical evidence regarding the potential adverse consequences of marijuana legalization.”
Authors concluded: “The present study used prospective, longitudinal data that spanned more than 20 years to examine whether patterns of marijuana use from adolescence to young adulthood were related to indicators of physical and mental health in adulthood. … Overall, data from this sample provide little to no evidence to suggest that patterns of marijuana use from adolescence to young adulthood … were negatively related to the indicators of physical or mental health studied. … This is particularly striking given that men in the early onset chronic group were using marijuana (on average) once per week by late adolescence and continued using marijuana approximately 3-4 times a week from age 20 to 26 years.”
Full text of the study, “Chronic adolescent marijuana use as a risk factor for physical and mental health problems in young adult men,” appears online here.