The proof is in the pudding: patient engagement in studying cannabidiol in mild cognitive impairment

Patient engagement (PE) in clinical trials has gained importance yet remains uncommon, particularly in patients with mild cognitive impairment (MCI), a critical precursor to Alzheimer's disease (AD). Cannabidiol (CBD) shows potential in slowing MCI progression due to its neuroprotective and anti-inflammatory properties. In CBD research, PE is underutilized too. To design a study on CBD for MCI, we administered an online survey to individuals with MCI to better understand their preferences for trial setup and outcomes.

We asked 209 individuals with MCI to complete an online survey assessing (i) willingness to participate in a trial using CBD; (ii) importance of improvements in various domains; (iii) acceptance of adverse events (AEs); (iv) reasons for AE-related dropout; (v) willingness to undergo blood sampling and lumbar puncture to assess AD pathology; and (vi) willingness to participate in a trial with a 50% chance of receiving a placebo. Data were analyzed with descriptive statistics.

N = 118 agreed to participate and N = 88 completed the survey. Participants prioritized improvement in cognitive abilities (87.5%), followed by quality of life (63.6%), daily activities (55.7%), sleep (55.7%), pain (52.3%), mood (52.3%), behavior (48.9%), and anxiety (43.2%). Headache (55.7%) was the least accepted AE followed by nausea (46.6%), fatigue (35.2%), and diarrhea (35.2%). Persistent diarrhea (90.9%) and severe fatigue (84.1%) were the main reasons for potential dropout. While most would undergo blood sampling (67.0%), only a minority (21.6%) would accept lumbar puncture. One-third were ready to participate (34.1%), while 54.5% were interested pending details. Among those in favor of participation, 71.6% would participate even with a 50% chance of placebo.

Our study identified cognitive improvement as highly relevant for patients, indicating cognitive assessment tools as primary endpoints in MCI research. Given concerns about AEs, dose titration should be carefully considered to enhance acceptance and prevent AEs. Blood sampling seems well-accepted for AD biomarker assessment. Despite potential AEs, participation in a trial using CBD for MCI is seen as attractive, even under placebo-controlled conditions. This cross-sectional study emphasizes the importance of patient engagement in designing high-quality trials for using CBD to treat MCI.