CBD in Treatment-Resistant Epilepsy

For most of the twentieth century, CBD was a footnote — an unglamorous cousin of THC without the intoxicating effects that made cannabis controversial. Its return to medicine began, quietly, in the treatment of children with epilepsies that no available drug could touch.

The pivotal moment was Dravet syndrome. A rare, catastrophic childhood epilepsy, Dravet had resisted essentially every anticonvulsant on the market. Case reports of dramatic seizure reduction on plant-derived CBD accumulated through the 2010s, culminating in the trials that led to the 2018 FDA approval of Epidiolex, a purified CBD formulation.

The mechanism is still incompletely understood. CBD is a promiscuous molecule; it affects sodium channels, GPR55, adenosine reuptake and more. The clinical effect, however, is robust. In Dravet, Lennox-Gastaut and tuberous sclerosis complex, CBD produces meaningful reductions in seizure frequency for a substantial minority of patients.

It is not a miracle drug. Some patients do not respond; some develop liver enzyme changes; some experience sedation. But the story is a useful corrective to two lazy narratives — that cannabis has no medical value, and that it has infinite medical value. The truth, as usual, is specific: for these patients, this molecule, at these doses, does this measurable thing.

That is what medicine is supposed to look like.