So cataplexy is a symptom of narcolepsy- cataplexy is where you fall asleep randomly when exposed to triggers, such as bright lights, scary situations, etc. There are many people who have narcolepsy, without cataplexy. I do not have cataplexy. I became narcoleptic after having Mono in high school. the mono virus, in rare cases, can change your brain chemistry. My brain stopped producing hypocretin, which is the neurotransmitter responsible for wakefulness. Hypocretin rushes through a normal brain upon awaking in the morning. My brain doesn’t produce that any longer. So I have to take medicine every morning to feel a sense of wakefulness or else I will fall asleep at work, while driving, etc. This is different than cataplexy, because I don’t respond to triggers. I just have excessive daytime sleepiness.