“There is insufficient evidence from moderate-quality or high-quality studies to assess whether there is a treatment effect of Cannabis sativa, CBD:THC combinations, or oral cannabis extracts,” they wrote.
There were three randomized, controlled trials that also looked at complete seizure freedom, finding a sixfold higher likelihood of total seizure freedom with CBD, compared with placebo. However, the number needed to treat to achieve this was 171, and again, the quality of evidence was described as “mixed.”
Just over half of patients treated with CBD reported improved quality of life, and significantly more parents and caregivers of those treated with CBD said the patient’s overall condition had improved. The pooled estimates from observational studies suggested that 55.8% of patients experienced improvements in their quality of life when using cannabinoids.
Studies involving patients with Dravet syndrome reported the greatest improvements in quality of life, compared with studies involving a mix of epilepsy syndromes. However, the authors noted that the studies that involved Dravet syndrome patients were all case series in which every patient responded and suggested they should be interpreted with caution.