EVIDENCE LIBRARY
People Reported Clearer Heads After Nightly CBD. Did Their Cognitive Scores Improve?
A randomized trial assigned 30 participants with primary insomnia to 150 mg CBD or placebo taken sublingually before bed for two weeks. Participants completed computerized cognitive tests and separately recorded how they felt. The study allows a comparison between those two kinds of outcome.
What the tests and ratings showed
The test battery covered attention, reasoning, information processing, executive function, and memory. The researchers reported no significant CBD effect on those cognitive tests. Some subjective measures, including clear-headedness and calmness, favored CBD. Participants receiving CBD also more often reported dry mouth.
Why the measurements should stay separate
A report of feeling clearer is a meaningful description of the participant’s experience. It answers a different question from whether attention or working-memory scores improved. In a trial with 15 people per group and two weeks of dosing, the results describe the studied regimen and sample. A conclusion about driving, a different formulation, or a longer course requires data addressing that question.