Actually, the condition or syndrome, or whatever you want to call it, was first described by psychiatrists in the 1800s. The terms they used are slightly different--acute exhaustive mania, lethal catatonia, and some other terms--but psychiatrists were the first ones to describe it.
This was before cocaine. This is the mid-1800s. Where did you see these patients? Well, we mentioned that a psychiatric disease can be the underlyer; in the 1800s all those patients were in hospital, so that's where they saw it.
There's a theory--and I would emphasize that it's only a theory--that maybe one of the reasons we're seeing it more in psychiatric patients outside hospitals is that it's now our preference to keep psychiatric patients outside and living as normal human beings whenever possible, but if their disease becomes out of control, excited delirium is a possible--rare, but possible--consequence of that.