UK medical cannabis patients with insomnia reported improved sleep quality over 18 months

Sleep quality scores (SQS) improved from 2.66 at baseline to 5.67 at one month (P<0.001) and remained significantly improved at 18 months (3.81, P<0.001), though improvements diminished over time. GAD-7 anxiety scores also improved significantly through 18 months. EQ-5D-5L quality of life showed improvements in usual activities, pain/discomfort, and anxiety/depression dimensions. Only 8.87% of participants reported adverse events, none disabling or life-threatening.

Case series from the UK Medical Cannabis Registry (UKMCR) analyzing 124 patients diagnosed with primary insomnia who were prescribed cannabis-based medicinal products. Patient-reported outcome measures (PROMs) assessed at baseline, 1, 3, 6, 12, and 18 months. Adverse events classified per CTCAE version 4.0.

Current insomnia treatments have significant limitations including dependency risk and side effects. This is among the longest follow-up periods for medical cannabis and insomnia, showing sustained but declining benefits that raise questions about tolerance.

The pattern of initial strong improvement followed by gradual decline is consistent with tolerance development, a concern with many sleep medications. The 18-month follow-up is unusually long for cannabis sleep research and provides a more realistic picture of real-world outcomes.

No control group or randomization; case series from a voluntary registry. Patients self-selected into treatment. Declining improvement over time could reflect tolerance, regression to the mean, or changing patient populations. Product formulations and doses varied across patients.