Answer:
LSD is a hallucinogen. While I'm not sure of any reversal agent (you may want to do further research on that if possible) there are many therapeutic means to dealing with the drug such as Cognitive Behavioral Therapy: a means used to help the process of creating healthy thoughts and recognizing faulty ones (this method can be used for more than just drug abuse, however).
Step-by-step explanation:
It is considered a hallucinogen as it may give people auditory and visual hallucinations, things that they may see and feel but that are not necessarily taking place. I've read that there are behavioral treatments for LSD but have not come across a medical means to stopping it's effects.