CBD for Insomnia: Higher Well-Being Scores Were Already Present Before Treatment
Higher well-being scores during a CBD insomnia trial cannot all be credited to CBD: the group later receiving CBD already had higher scores at screening. The trial also found mostly null primary sleep results, alongside a narrower positive finding for actigraphy-derived sleep efficiency.
What the trial compared
The published analysis included 30 completers with primary insomnia, 15 per group. Following a placebo run-in, participants took 150 mg CBD or a corn-oil placebo sublingually each night for two weeks. Sleep diaries, wrist actigraphy and questionnaires supplied different outcome measures.
Thirty-four participants were randomized and 32 completed the final visit; the authors analyzed the prespecified 30-completer pool. Placebo responders were excluded before randomization, which also affects how broadly the results can be applied.
Baseline differences change the causal question
The CBD group’s well-being score exceeded placebo by approximately 2.6 points at screening and again at the end of treatment. A difference that predates active dosing cannot establish a treatment-induced gain simply because it remains statistically significant later.
The appropriate question is whether treatment produced a greater change from the relevant baseline. The authors described sustained higher well-being and acknowledged the initial imbalance; this should not be rewritten as proof that CBD created the entire between-group difference.
Keep the primary and secondary findings together
Insomnia severity and diary-based sleep-onset latency, sleep efficiency and wake time after sleep onset did not significantly differ between treatments. Actigraphy-derived sleep efficiency was significantly higher in the CBD group during dosing, including at the final assessment.
Self-reported sleep quality improved relative to placebo after one week but not at two weeks. These findings support endpoint-specific interpretation, rather than either dismissing every signal or claiming broad efficacy across insomnia symptoms.
What remains uncertain
The study was short, small and evaluated many outcomes. Food intake was not characterized and CBD concentrations were not measured, leaving achieved exposure uncertain. Actigraphy estimates sleep from movement; it is not the same measurement as laboratory polysomnography.
The same trial also generated a separate daytime cognition publication. Sleep, subjective well-being and cognitive performance are distinct questions within one participant cohort, not independent demonstrations of benefit.
Related: Daytime cognition and subjective outcomes from the same insomnia trial.
Primary research
Cannabidiol for moderate–severe insomnia: a randomized controlled pilot trial of 150 mg of nightly dosing. DOI: 10.5664/jcsm.10998.
