A preliminary study on the influence of cannabis and opioid use on weight loss and mental health biomarkers post weight loss surgery
The number of people with obesity decided to undergo weight loss surgery (WLS) has consistently risen in the past decade, from 158,000 patients in 2011 to 252,000 in 2018. Following surgery, a substantial subpopulation, approximated between 10-20% of patients, utilized cannabis and/or opioids for pain management purposes. However, the impacts of these substances on post-WLS anxiety and depression are unclear and under-investigated, despite these psychological conditions being very common in WLS patients.
Only recently was the first clinical study on the influence of independent or combined cannabis and opioids use on depression and anxiety as well as total percent weight loss conducted. In this study, patients’ pre-surgery depression and anxiety levels were assessed via measurement of biomarkers including serotonin and cortisol collected during procedures and post-surgery levels via self-report on established tests. Preliminary data suggested that patients who used cannabis or a combination of cannabis and opioids achieved a greater total percent weight loss than those without substance use. Cannabis users, however, reported greater depressive symptoms and higher stress biomarkers than non-users. Combination users experienced an even higher prevalence of depression and anxiety post-WLS, but less stress biomarkers than none-users and cannabis-only users. Scientists hypothesized that such low levels of cortisol and serotonin result from the opioid’s “blunting effect” on hormones instead of an actual lessened depressive condition. Interestingly, no patients only used opioids.
Future studies in which a larger sample size, utilization of a cohort design to address causality, and examination of the type, dose, and route of cannabis and opioid administration are necessary for a more complete understanding of the impact of combined cannabis and opioids use on patients following WLS.