To the Editor.—
The authors wonder at the phenomenon of two "bad trips" occurring in an individual who had several other pleasant experiences with lysergic acid diethylamide (LSD). I have reread the article and fail to find any clue as to how the authors know that the drugs involved were LSD. In fact, they liken the bad trips to those seen in amphetamine users, and it is well known that what is sold in the drug culture as LSD may be something else entirely or at least a combination of drugs, commonly including amphetamine. Without such proof as to the exact nature of the drugs taken, the report loses validity as a case report of a specific drug reaction.