From the Research
Yes, THC-induced seizures are possible, though they are relatively uncommon. THC, the main psychoactive component in cannabis, typically has anticonvulsant properties at low to moderate doses, but at high doses it can potentially trigger seizures in susceptible individuals 1. This paradoxical effect occurs because THC affects the endocannabinoid system, which plays a role in regulating neuronal excitability. The risk of THC-induced seizures appears higher in individuals with pre-existing seizure disorders, those taking very high doses, or when using synthetic cannabinoids which can be much more potent than natural THC.
Key Points to Consider
- The mechanism likely involves THC's interaction with CB1 receptors in the brain, which at excessive levels can disrupt the balance between excitatory and inhibitory neurotransmission 2.
- If someone experiences a seizure after THC exposure, they should seek immediate medical attention and avoid further cannabis use, as repeated exposure could potentially lower their seizure threshold over time.
- A case report described a 17-year-old girl with no prior history of seizures who presented with a generalized tonic-clonic seizure after daily vaping of highly concentrated THC marijuana 1.
- Another study found that low doses of Δ9-THC are anticonvulsant against hyperthermia-induced seizures in a mouse model of Dravet syndrome, but sub-chronic oral administration of Δ9-THC or CBD alone did not affect spontaneous seizure frequency or mortality 2.
Clinical Implications
- Clinicians should be aware of the potential for THC-induced seizures, particularly in susceptible individuals.
- Patients with a history of seizure disorders should be cautious when using cannabis products, especially those with high THC content.
- Further research is needed to fully understand the relationship between THC and seizure susceptibility, as well as the potential interactions between THC and other cannabinoids like CBD 3.