PROJECT SUMMARY
More and more US states are legalizing cannabis for medical purposes, and the growing popularity of medical
cannabis has outpaced scientific understanding of its benefits and harms. The most commonly reported reason
for using medical cannabis is chronic pain. However, for the vast majority of medical cannabis users with
chronic pain, the proximal antecedents of cannabis use, and the health benefits and risks of use, are unknown.
This is because the best available evidence that pain triggers medical cannabis use is based on retrospective
reports that are subject to problems of recall bias, and the best available evidence that medical cannabis
alleviates pain, with few adverse side effects, is based on clinical trials that lack external validity. Clinical trials
lack external validity because the types of cannabis administered bear little resemblance to medical dispensary
cannabis, and because the sterile lab environments of clinical trials bear little resemblance to real-world
settings. Therefore, research on the proximal antecedents and subjective effects of medical cannabis calls for
measurement in the natural ecology. This project will examine proximal antecedents and acute effects of
cannabis use in medical users’ natural environments. It will explore an array of possible antecedents of
cannabis use among medical users, including pain but also negative affect and cannabis withdrawal – a
symptom of cannabis use disorder (CUD). Because research shows that the prevalence of CUD is elevated
among medical cannabis users, research is needed to understand mechanisms that might underlie the
transition from medical cannabis use to CUD. Contemporary models of addiction posit that subjective states
during periods of acute abstinence and subjective drug effects are key mechanisms in addiction development
and maintenance. However, it is not known if and how the proximal antecedents and subjective effects of
cannabis use relate to CUD severity among medical users. If medical cannabis causes a high or alleviates pain
and negative affect in the everyday lives of medical users, for example, it is important to know whether these
effects are associated with CUD severity. This information will bolster the development of safer and more
effective treatment options. To address gaps in existing knowledge, the current proposal will use ecological
momentary assessment (EMA) in a group of young-adult medical cannabis users to examine three specific
aims: (1) Characterize the proximal antecedents of cannabis use in the daily lives of young-adult medical
cannabis users; (2) characterize the acute subjective effects of cannabis in the daily lives of young-adult medical
cannabis users; and (3) test whether the proximal antecedents and subjective effects of medical cannabis use
vary as a function CUD severity. This information will help patients, physicians, and policymakers to make
evidence-based decisions about the pros and cons of whether to use/recommend cannabis for medical
purposes.
