It's actually gotten a bad rap over the years, and very unfairly. There is a chemical in it that in huge, and I mean MASSIVE doses, would make one hallucinate. It's called tujone. However, the amount of tujone in absinthe is equivalent to you and three friends floating on a raft in the Pacific Ocean, you, the raft, and your friends representing the tujone, you see.
Really, why there are so many horror stories associated with absinthe is probably because it is very high in ******* content. Anything with a high ******* content will make one go nuts, if the conditions are right.
That being said, there is something different about an absinthe high.......