Background: Cannabis is the most widely used illicit substance worldwide. The aim of the present study was to assess self-reported Quality of Life (QoL) among cannabis users in a large representative sample.
Methods: We analyzed data from the National Epidemiological Survey of Alcohol and Related Conditions (NESARC, n = 43,093). Health-related QoL was assessed using the Short-form 12-item Health Survey (SF-12). The contribution of cannabis use and cannabis use disorders (CUD) to SF-12 scores was assessed using multiple linear regressions models.
Results: The prevalence of cannabis use and CUD in the last 12 months was 4.1% and 1.5%, respectively. Mean SF-12 mental summary scores were significantly lower (indicating a lower QoL) among female and male cannabis users compared to non-users (by 0.6 standard deviations (SD) and 0.3 SD, respectively), and among females and males with CUD compared to those without CUD (by 0.9 SD and 0.4 SD, respectively). Controlling for sociodemographic variables and mental illness, each joint smoked daily was associated with a greater decrease in mental QoL summary scores in females (0.1 SD) compared to males (0.03 SD).
Conclusions: Cannabis use and CUD were associated with lower self-reported mental QoL. Specifically, our findings showed that cannabis use and CUD have a more significant effect on self-reported mental health QoL among female users. Assessing severity of cannabis use and impact of CUD should take into account functional and emotional outcomes. This may particularly aid in detecting the impact of cannabis use and CUD on mental health-related QoL among females.