You're confusing chronic abuse with overdose. A psychedelic overdose just means you're in a chemically induced psychosis. It's easy to die in this state, but by

You're confusing chronic abuse with overdose. A psychedelic overdose just means you're in a chemically induced psychosis. It's easy to die in this state, but by falling off a balcony, not because you stop breathing. Some of the newfangled psychedelics coming out of China can cause serotonin syndrome, however, which can be fatal. But it's not practically possible to overdose on the traditional psychedelics.