Changes in sleep quality among patients prescribed medicinal cannabis: Real-world evidence from Project Twenty 21
Authors
Michael T Lynskey, Alkyoni Athanasiou-Fragkouli, Hannah Thurgur, Anne Katrin Schlag and David J Nutt
Published
October 3, 2025
Abstract
Background
Emerging research suggests that prescribed cannabinoids may improve sleep quality both among people with formal diagnoses of insomnia and among those experiencing disturbed sleep in the context of other chronic health conditions.
Objective
To document patterns of disturbed sleep among individuals seeking treatment with prescribed cannabis for chronic health conditions and to examine whether the use of prescribed cannabinoids ameliorates these problems.
Sample
Data were derived from Project Twenty 21, an observational study of patients receiving medicinal cannabis from multiple clinics in the United Kingdom. Data at entry to treatment were available for 3998 individuals (34.4% female) seeking treatment for chronic conditions other than insomnia. Three-month follow-up data on patterns of sleep were available for 2017 patients, and three-monthly reports of sleep quality for up to 12 months were available for 929 individuals.
Measures
Self-report ratings of sleep disturbance, quality of life, and condition-specific symptomatology were available at the time of entry to treatment and at three monthly intervals. Additional data included sociodemographic characteristics, primary reason for seeking treatment, use of prescribed sleep medications, and details of prescribed cannabis.
Results
31% reported a secondary diagnosis of insomnia. Receipt of prescribed cannabinoids was associated with a large and clinically significant improvement in sleep quality, additional aspects of quality of life, and condition-specific symptomatology (all p < .001). A diagnosis of insomnia was associated with a significantly greater improvement in sleep quality (p < .001). There was a 30% reduction in the proportion of people using sleep medications (Z = 1.9, p < .05), and improvements in sleep quality observed at 3 months were maintained for up to 12 months, with these improvements being greater in people with insomnia.
Conclusions
Sleep disturbances are common among individuals seeking medical cannabinoid treatment for other conditions. Prescribed cannabinoids are associated with a reduction in these disturbances and parallel improvements in other domains. Given the centrality of sleep to quality of life, practitioners treating a range of chronic illnesses should consider the potential benefits of prescribed cannabinoids both for targeting the primary condition and the potential ancillary benefits on sleep quality.
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