Introduction: Cannabis is now the most commonly used illicit drug in the United States and use is increasing. Frequent cannabis use has been associated with adverse social and health effects. We sought to evaluate the relationship between recreational cannabis use and Quality of Life (QoL), a person-centered measure that characterizes the overall sense of health and wellbeing. We hypothesized that QoL would be unchanged or increased among recreational cannabis users, who did not meet criteria for a Cannabis Use Disorder (CUD) and that QoL would be lower among those who met criteria for a CUD.
Methods: We conducted a systematic review, employing guidelines from Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The results were categorized into tables and identified trends.
Results: Fourteen studies met our pre-defined selection criteria. The studies were heterogeneous and their quality was low. With one exception, we did not identify any population for whom cannabis use was associated with improved QoL. QoL was lower in persons who used cannabis heavily, or who met criteria for CUD. However, this association was inconsistent and the magnitude was weaker than the relationship between QoL and use of other addictive substances (including tobacco and illicit drugs).
Conclusion: In this systematic review, heavy cannabis use or CUD was associated with reduced QoL. It is unknown whether reduced QoL drives cannabis use, or whether cannabis use can lead to reduced QoL. Prospective studies are needed to evaluate the causal relationship between cannabis and QoL.
Scientific significance: Furthering the understanding of the relationship between cannabis and QoL can inform public policy, prevention efforts, outcomes, and an objective understanding of the effects of cannabis users. (Am J Addict 2017;26:8-25).
© 2016 American Academy of Addiction Psychiatry.