A long-term study suggests that cannabis-based medical treatments may bring lasting relief to people with chronic insomnia.
Over 18 months, patients reported not only better sleep but also reduced anxiety, less depression, and even lower pain levels. Side effects were mild and temporary for most, making cannabis a potential alternative where traditional sleep medications fall short.
Cannabis-Based Products Show Promise
People living with insomnia who used cannabis-based medical treatments reported sleeping better for as long as 18 months, according to research published August 27 in the open-access journal PLOS Mental Health. The study was led by Arushika Aggarwal of Imperial College London, U.K., along with her colleagues.
Sleep problems affect roughly one in three people, and about 10 percent of adults meet the criteria for an insomnia disorder. Standard treatment options are often hard to access, and medications approved for insomnia carry a risk of dependence.
To explore whether cannabis-based therapies might ease insomnia, the researchers reviewed outcomes from 124 patients who were prescribed medical cannabis. They tracked changes in reported sleep quality, anxiety and depression levels, and overall quality of life across one to 18 months of treatment.
Lasting Sleep and Mental Health Benefits
Patients consistently reported better sleep throughout the 18-month period. They also noted reduced anxiety and depression, along with lower levels of pain. Around nine percent experienced side effects such as fatigue, dry mouth, or insomnia, but none were considered serious. While more rigorous randomized controlled trials are required to confirm safety and effectiveness, the results suggest that cannabis-based medical products may provide a new avenue for improving sleep among people with chronic insomnia.
Co-author Dr. Simon Erridge, Research Director at Curaleaf Clinic, explained: “Over an 18-month period, our study showed that treatment for insomnia with cannabis-based medicinal products was associated with sustained improvements in subjective sleep quality and anxiety symptoms. These findings support the potential role of medical cannabis as a medical option where conventional treatments have proven ineffective, though further randomised trials are needed to confirm long-term efficacy.”
Importance of Long-Term Monitoring
He adds: “Conducting this long-term study provided valuable real-world evidence on patient outcomes that go beyond what we typically see in short-term trials. It was particularly interesting to observe signs of potential tolerance over time, which highlights the importance of continued monitoring and individualised treatment plans.”
Reference: “UK Medical Cannabis Registry: A clinical outcomes analysis for insomnia” by Arushika Aggarwal, Simon Erridge, Isaac Cowley, Lilia Evans, Madhur Varadpande, Evonne Clarke, Katy McLachlan, Ross Coomber, James J. Rucker, Mark W. Weatherall and Mikael H. Sodergren, 27 August 2025, PLOS Mental Health.
DOI: 10.1371/journal.pmen.0000390
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