How cannabis may ease ‘chemo brain’ and improve sleep for cancer patients

28 Apr 2023
How cannabis may ease ‘chemo brain’ and improve sleep for cancer patients

Cancer patients who use cannabis to address their symptoms have less pain and sleep better, according to new University of Colorado research.

But they also experience another, unexpected, benefit: After a few weeks of sustained use, they seem to think more clearly.

“When you’re in a lot of pain, it’s hard to think,” said senior author Angela Bryan, a professor of psychology and neuroscience at CU Boulder and a cancer survivor.

“We found that when patients’ pain levels came down after using cannabis for a while, their cognition got better.”

The small but groundbreaking study, published this week in the journal Exploration in Medicine, is among the first to assess how cannabis bought at dispensaries impacts cancer symptoms or chemotherapy side effects.

It also explored the variety of products cancer patients use now that it is legal in most states. 

Because federal law prohibits university researchers from possessing or distributing cannabis for research unless it’s government-issued or of pharmaceutical grade, most studies have looked only at prescription products or government cannabis strains that tend to be less potent and lack the variety of over-the-counter offerings.

As a workaround to this challenge, Bryan collaborated with oncologists at the CU Anschutz Medical Campus to observe 25 cancer patients who used cannabis over two weeks. 

After a baseline appointment to assess their pain levels, sleep patterns and cognition, participants were asked to purchase the edible product of their choosing from a dispensary.

Patients selected chocolates, gummies, tinctures, pills, and baked goods from 18 different brands, all containing varying ratios of THC and CBD at a wide range of potencies. 

To study acute impacts, researchers drove a “mobile laboratory” (a Dodge Sprinter van sometimes referred to as the “cannavan”) to each patient’s home.

Participants underwent physical and cognitive assessments in the van before re-testing in the van after using cannabis in their homes.

Within an hour, the study found, cannabis eased patient’s pain significantly while also impairing their cognition and making them feel “high” (the higher the THC content, the higher they felt).

After two weeks of sustained use at the frequency of their choice, they had a follow-up exam and a different pattern emerged: Patients reported improvements in pain, sleep quality and cognitive function.

Some objective measures of cognitive function, including reaction times, also improved.

“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.”

The more people’s pain subsided, the more their cognition seemed to improve.

Those who ingested more CBD, a known anti-inflammatory, reported bigger improvements in sleep quality and pain intensity.

While larger controlled studies are needed, the authors say the findings raise an intriguing possibility: While some forms and dosages of cannabis for pain relief may impair thinking short-term, some regimens might improve cognition in the long run by reducing pain.

Source: University of Colorado Boulder