My friend took LSD and it made her anxiety worse. Another got an epileptic seizure while on LSD (never had one before or since the trip).
Not to say you shouldn't try it, I know several people who had positive experiences, but it's not 100% positive, as some people make it out to be.
(in before 'oh what they took wasn't actually LSD' from the 'LSD can do no harm' crowd)