Taking cannabidiol (CBD) before diagnostic imaging may alleviate anxiety in women with advanced breast cancer, according to a study published on December 16 in JAMA Network Open.

Led by Dr. Ilana Braun from the Dana-Farber Cancer Institute in Boston, the research showed that anxiety levels dropped significantly two to four hours after ingesting CBD. The study also confirmed the safety of orally consumed CBD. However, the overall reduction in anxiety scores did not differ significantly between women who took CBD and those who received a placebo.

“These findings are intriguing enough to warrant further investigation into CBD as a safe and potentially effective treatment for cancer-related anxiety,” the team wrote.

Anxiety is common in oncology settings, affecting roughly 20-25% of adults. While benzodiazepines are often prescribed to manage anxiety linked to diagnostic scans, these medications can cause side effects like confusion, memory loss, and addiction.

CBD, a compound derived from hemp (a close relative of marijuana), does not cause impairment as it lacks tetrahydrocannabinol (THC)—the psychoactive substance responsible for a “high.” CBD is already used medically to treat conditions like epilepsy and anxiety during MRI scans, and it does not carry addictive properties.

However, clinical data on CBD’s efficacy remains limited. To address this, Braun’s team conducted a randomized trial to determine whether a single 400-mg oral dose of FDA-approved CBD could reduce anxiety in women undergoing CT or PET scans for advanced breast cancer.

The study involved 50 women, evenly divided into two groups: one group received CBD, while the other took a placebo. Participants were randomly assigned (1:1) based on their initial anxiety levels. They ingested the study drug within 48 hours before their scans.

Researchers assessed anxiety using the “afraid” subscale of the Visual Analog Mood Scale (VAMS), measuring scores before and two to four hours after CBD or placebo ingestion. VAMS scores were converted into T-scores to evaluate mood changes, with a T-score above 20 indicating significant change and a score above 30 reflecting both significant and clinically meaningful change.

The results revealed that women who took CBD experienced slightly greater anxiety relief than the placebo group, though the difference was not statistically significant. Specifically, the CBD group showed a VAMS score change of -19.1 compared to -15.0 in the placebo group (p = 0.37).

Researchers attributed the lack of statistical significance to the small sample size, baseline score variations, and low correlation between pre- and post-drug VAMS scores.

Nonetheless, anxiety levels in the CBD group were significantly lower than in the placebo group between two and four hours after ingestion. T-scores were 51.5 for the CBD group and 58.0 for the placebo group (p = 0.02).

The study also found no severe adverse effects (grade 3 or 4 toxicity) among participants, reinforcing CBD’s safety profile.

“These findings contribute to existing evidence that a 400-mg oral dose of CBD can be safely administered to cancer patients,” the authors noted.

To advance this research, the team recommended future longitudinal trials that incorporate repeated anxiety measurements, wearable anxiety-tracking devices, a larger sample of patients with moderate to severe anxiety, and the use of the Patient Global Impressions Scale.

“A more robust study could allow researchers to definitively determine whether oral CBD, which we have shown to be safe in medically ill patients, effectively alleviates clinical anxiety in adults with cancer,” they concluded.