Anxiety is extremely common among adults receiving cancer care, with as many as one out of every four patients meeting the clinical criteria for anxiety.

Many patients with cancer also experience scan-related anxiety (scanxiety), a condition in which individuals develop anxiety related to getting imaging studies to assess the potential spread of cancer, evaluate response to treatment, or investigate cancer-related symptoms. There are not many good options for managing anxiety outside of benzodiazepines (medications like lorazepam or alprazolam). While benzodiazepines work, they can cause significant complications including falls and oversedation.

A new study conducted as a collaboration between researchers from Dana-Farber Cancer Institute and Mass General Brigham explores whether cannabidiol (CBD), a component of marijuana, can reduce anxiety levels, specifically among patients with advanced breast cancer before a scan assessing tumor burden. The randomized clinical trial compared patients who received 400 mg of CBD compared to patients who received a placebo.

While the study did not meet its primary endpoint of significant difference between groups in anxiety change scores, the researchers did find that anxiety levels were significantly lower 2-to-4 hours after ingesting CBD and that CBD was safe as a treatment for anxiety among patients with breast cancer. Their results are published in JAMA Network Open.

"Our results lay the groundwork for larger, more definitive trials testing CBD in patients with breast cancer and other cancers as a way of reducing anxiety," said co-first author Peter Chai, MD, of the Department of Emergency Medicine at Brigham and Women's Hospital. Chai is also a member of the Department of Psychosocial Oncology at Dana-Farber Cancer Institute.

"Our study also demonstrates high levels of interest in clinical trials to test treating anxiety with CBD and highlights the need to conduct follow-up studies to understand how CBD integrates into the armament of therapies to address cancer related anxiety," said corresponding author Ilana Braun, MD, of the Department of Psychiatry at the Brigham and Department of Supportive Oncology at Dana-Farber Cancer Institute. "We recruited patients at the height of the pandemic when clinical trials generally stagnated, but nearly three-quarters of potential participants expressed interest and many referred others to the study."

The team, led by Braun with co-first author Chai and co-first author Manan M. Nayak, Ph.D., MA, of the Dana-Farber Cancer Institute, measured whether administering one oral dose of 400mg, FDA-approved CBD would decrease the anxiety levels of patients with advanced breast cancer.

Participants at the Dana-Farber Cancer Institute's Breast Oncology Center were randomized into two groups: a control group (25 women receiving no treatment) and a treatment group (25 women receiving CBD). Anxiety levels among participants were assessed using the Visual Analog Mood Scale (VAMS) prior to and 2-to-4 hours following ingestion of the treatment drug. Participants who were randomly assigned to take CBD did not have a significantly greater reduction in anxiety after ingestion compared to patients who did not take CBD.

However, though the study did not achieve its primary endpoint, it did demonstrate that participants who consumed CBD experienced lower anxiety levels 2 to 4 hours after drug ingestion, suggesting that CBD does have anxiety-reducing properties.

According to the researchers, this finding suggests CBD's potential as an anxiety treatment for women with advanced breast cancer and clinical anxiety, necessitating further investigation.