Study: Cannabis Use Not Linked to Motivation Loss

Marijuana use by teens is not independently associated with an increased risk of  so-called ‘Amotivational syndrome,” according to longitudinal data published in the Journal of the International Neuropsychological Society.

A team of researchers affiliated with Florida International University assessed the association between cannabis use and motivation in a cohort of 401 adolescents (ages 14 to 17) over two years.

Authors reported that adolescents’ cannabis use was not associated with any significant changes in motivation, apathy, or engagement after investigators controlled for subjects’ use of alcohol and tobacco, among other potential confounders (such as age, sex, and depression).

They reported, “[D]espite significant increases in levels of cannabis use in our sample, change in cannabis use did not predict changes in motivation, which suggests that cannabis use may not lead to reductions in motivation over time.”

Responding to the study’s findings, NORML’s Deputy Director Paul Armentano said, “Modern science is setting the record straight and exposing much of the ‘reefer madness’ of the past decades. Unfortunately, many of these myths still remain prevalent in our society, and are often raised by politician in their efforts to justify the failed policies of marijuana prohibition and stigmatization It’s is time for America to set aside these myths and adopt cannabis policies based on facts, not fears”

The study’s authors concluded: “Our findings do not support a relationship between cannabis use and reductions in motivation over time in a sample of adolescents at risk for escalation in cannabis use. … The current study contributes to the extant literature by examining these associations longitudinally in a large sample of adolescent cannabis users while controlling for important and often overlooked confounds, including sex and depression. … Future studies should continue to examine these associations longitudinally to determine whether heavier levels of cannabis use lead to reductions in motivation, and whether these reductions may be responsible for poorer educational and later life outcomes.”

Full text of the study, “Evidence lacking for cannabis users slacking: A longitudinal analysis of escalating cannabis use and motivation among adolescents,” appears in the Journal of the International Neuropsychological Society.