Effects of delta-9 tetrahydrocannabinol and cannabidiol on cognitive outcomes following acute use of cannabis for chronic pain.

Rationale

An estimated two-thirds of medical cannabis users in the United States are motivated by chronic pain, but clinical guidance remains guarded as to whether the potential benefit of cannabinoids for pain outweighs potential risks, such as effects on cognition.

Objectives

In a study where participants experienced benefits of cannabinoids for pain and tension, we evaluated cannabis effects on executive function, processing speed, memory, and verbal learning following acute use for chronic, non-specific low back pain.

Methods

Participants were in one of three self-selected edible cannabis groups: a) CBD-dominant, b) THC-dominant, or c) a mixed ratio of CBD to THC and completed a battery of cognitive tasks at pre-use, 1 h post-use use, and 2 h post-use.

Results

Among 183 participants (56.8% female; Mage = 45.6), those in the group using CBD outperformed participants using CBD + THC 1 h post use in working memory and produced more stable scores in verbal learning after use than participants using THC or CBD + THC. Additionally, while older age was associated with better working memory in the CBD group before use, that relationship was progressively attenuated over the subsequent timepoints. There were no significant effects of cannabis use on cognition in the domains of executive function, episodic memory, or processing speed.

Conclusions

Given the ubiquity of cannabis use for chronic pain and the ongoing call for more data, this study is relevant for informing clinical guidance on whether, and how, cannabis could be used in this context. In particular, understanding the acute impact on cognition from cannabis is critical, as cognitive functioning directly affects patients' daily lives and quality of life.