I would assume as the poster is talking about raves, they are referencing ketamine or MDMA, and both of these are more than capable of making you forget who you are, let alone who your friends are.
Primarily it is an empathogenic[1] drug, not a hallucinogen.
Or so I have heard.
The serotonergic effects are a completely different matter.
[0] https://www.erowid.org/library/books_online/pihkal/pihkal109...
Someone has misinformed you. Please do your own research. There is absolutely no mention of anything remotely like what you are describing in the wikipedia article: http://en.wikipedia.org/wiki/MDMA
Unless the usual method of taking LSD is via pill form.
But I hear MDMA does not induce hours of hallucinations either, so perhaps LSD does come in pill form with logos on it.