I got interested in that, the most authoritative source I could find on the fly (the NIH) seems to say it might cause flashbacks, but "LSD is not considered an

I got interested in that, the most authoritative source I could find on the fly (the NIH) seems to say it might cause flashbacks, but "LSD is not considered an addictive drug since it does not produce compulsive drug-seeking behavior.": http://www.nida.nih.gov/infofacts/hallucinogens.html http://www.nida.nih.gov/infofacts/hallucinogens.html