has cannabis use been shown to potentially predict risk of developing MDD, but it has also been shown to promote depressive symptom progression [5, 106]. Despite a substantial collection for the harmful implications of cannabis on depressive outcomes, there are other studies that have found no correlation between cannabis use and later MDD diagnosis or symptom severity after controlling for multiple confounding factors, including other illicit drug use, education and childhood upbringing [34, 51, 111]. Nonetheless, there have been no randomized, clinical trials for the use of cannabinoids in depression. There are, however, studies that have analyzed depression symptoms as secondary outcome measurements in participants with other disorders, such as chronic pain, but no significant therapeutic benefit has been found in association with the administered cannabinoids, including nabiximols and dronabinol [109]. Thus far, the literature suggests more evidence for harms, rather than therapeutic effects, of cannabis in MDD (Table 1); research gaps need to be addressed in future research with prospective, controlled study designs.
