Shock

Shock is a 1946 horror film -because it stars Vincent Price, I guess. It might be better described as a thriller.

via Youtube:

At the time of its release, the New York Times worried about the medical consequences:

It is not that the picture is cheaply sensational, artistically: that is a standard condition which one might overlook. It is rather that, in telling a fraudulent and unhealthy tale, it tends to excite apprehension against the treatment of nervous disorders.

MSN has an overview.