Cannabis May Ease “Chemo Brain” And Improve Sleep For Cancer Patients

“When you’re in a lot of pain, it’s hard to think,” said Angela Bryan, a professor of psychology and neuroscience at CU Boulder and the study’s senior author. “We found that when patients’ pain levels came down after using cannabis for a while, their cognition got better.”

Studies suggest that up to 40% of American cancer patients use cannabis to ease their symptoms, but only one-third of doctors feel comfortable about advising them on the topic. Researchers use government-supplied or synthetic varieties of cannabis for investigation because federal law currently prohibits university researchers from using cannabis for study unless it is government used or of pharmaceutical grade. As such studies only look at prescription products or government cannabis strains that tend to be less potent and lack the variety of over-the-counter offerings which limits knowledge of potential uses. 

Collaborating with Dr. Ross Camidge and Dr. Daniel Bowels, who are oncologists at the CU Anschutz Medical Campus, they observed 25 cancer patients who used cannabis over a 2-week period. Patient pain levels, sleep patterns, and cognition were assessed at baseline who purchased an edible product of their choosing from a dispensary that spanned over 18 brands ranging from chocolate, gummies, pills, tinctures, and baked goods with varying ratios of THC and CBD in varied potencies. 

“This tells us that people are open to trying whatever they think might be useful, but there’s just not much data out there to guide them on what works best for what,” said Bryan.

A mobile laboratory was used to go to each patient’s home to study the acute impacts in which the participants underwent physical and cognitive assessments before using cannabis and after they had used cannabis in their homes and returned to the van. Additionally, after two weeks of sustained use at the frequency of the patient's choice, the participants also underwent a follow-up examination.

Initially, within an hour of use, cannabis use was found to have eased the patients’ pain level significantly while also slightly impairing their cognition and making them feel high, with higher concentrations of THC content making them feel higher than lower concentrations. However, a positive pattern began to emerge: after two weeks of sustained use, the participants reported improvements in pain levels, sleep quality, and cognitive function. 

Additionally, there were also some objective measures of improved reaction times and cognitive function. To add to this as participant pain subsided the more their cognition appeared to improve. Those who had ingested higher CBD concentrations, a known anti-inflammatory, also reported greater improvements in both pain intensity as well as sleep quality. 

“We thought we might see some problems with cognitive function,” said Bryan, noting that both cannabis and chemotherapy have been previously associated with impaired thinking. “But people actually felt like they were thinking more clearly. It was a surprise.”

It was noted that while these findings are very positive, larger controlled studies are required to make firm conclusions and intriguing possibilities have been revealed: some forms and dosages for pain relief may impair thinning over the short term, but some may improve cognition over the long term by reducing pain levels. 

“We know oncologists and patients are concerned about the possible negative impact of cancer treatment on cognitive function, so the potential, indirect role of cannabis use on improving subjective cognitive function should be studied further,” said first author Gregory Giordano, a professional research assistant in the Department of Psychology and Neuroscience.

Related to this study on personal experience Bryan was diagnosed with breast cancer in 2017 and turned to cannabis-infused edibles to create her own custom regimen of products and doses when her pain was high after surgery and chemotherapy. While she admits that she was not completely pain-free she did not have to take a single opioid during her treatment. 

“I was extremely lucky because I had some knowledge about this. Most patients don’t,” she said. “Either they don’t know it’s an option or they’ve got well-meaning but potentially under-informed budtenders advising them.”

Moving forward she hopes to conduct larger similar studies and to enable doctors and oncologists as well as patients themselves to make better well-informed decisions.