Study: Effectiveness of CBD for epilepsy stronger over time

March 18, 2021

CBD can help with epileptic seizures. An American study now shows that the effectiveness of the cannabinoid increases over a longer period of therapy. In the second year of treatment, the significant effect on the frequency and severity of seizures was clearly more pronounced than at the beginning.

Reduction of epilepsy seizures with CBD extract

The study by the Department of Neurology and the UAB Epilepsy Center at the University of Alabama at Birmingham, USA, involved 169 people with treatment-resistant epilepsy – 89 of them children and 80 adults. They received a CBD extract (Epidyolex). The researchers defined the response to treatment with cannabidiol by a reduction in seizure frequency of 50 percent or more.

This significant reduction in seizure frequency was more pronounced after 2 years of treatment than within the first month of starting therapy. In addition, the research team found that this effect was more pronounced in the 80 adults after one year than in the 89 children in the study. The percentage of children who achieved a reduction in seizure frequency by half or more was 44% in the first month, 41% in the first year and 61% in the second year. For adults, this rate was 34% in the first month, 53% in the first year and 71% in the second year.

Greatest improvement in adults in the second year of therapy

Seizure severity was also significantly reduced by the CBD product: Children showed a 52% seizure reduction in the first month, a 51% reduction in the first year and a 75% reduction in the second year. Seizure reduction in adults was even significantly higher, at 60%, 81% and 85%. In comparison, adults reported greater improvement than children after two years of therapy.

Refractory epilepsy – resistant to treatment

According to the World Health Organisation (WHO), epilepsy affects about 50 million people worldwide. It is one of the most common chronic neurological diseases. The disease is characterised by recurrent seizures that either affect the whole body or only a specific part. Occasionally, people with epilepsy may also lose consciousness during seizures. Refractory epilepsy is a difficult-to-treat form of the disease that does not respond to antiepileptic drugs.



Gaston TE, Ampah SB, Martina Bebin E, Grayson LP, Cutter GR, Hernando K, Szaflarski JP; UAB CBD Program. Long-term safety and efficacy of highly purified cannabidiol for treatment refractory epilepsy. Epilepsy Behav. 2021 Mar 2;117:107862. doi: 10.1016/j.yebeh.2021.107862. Epub ahead of print. PMID: 33667843.

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