This could be hypothesized to be either due to effects of having epilepsy such as increased rates of comorbid mental illness, social factors such as lower socioeconomic status, or due a shared diathesis for addictive behavior and seizures due to the behavior of pathological neural networks in the brain
The most common reasons include taking longer puffs than the standard 3-second laboratory test puff, chain vaping without breaks, storage in a warm environment, or simply being a heavier user than average
On the other hand, if flavours are to be banned for vaping products and allowed in regular cigarettes, as seems to be the current trend in the US, vaping would decline by over 10%, and many former smokers would go back to smoking regular cigarettes, leading to an increase in cancer and mortality rates
So the audience knows the characters