LSD has zero physical addiction potential. It is not physically addictive and it is not a drug that you will want to immediately do again.

However, as with many drugs, users can (and do) become psychologically dependent on LSD. Its pyrotechnic effects and dazzling high can become a distraction, perhaps even an escape from reality for some people. It can become very hard to function in "consensus reality" if you are taking LSD on a regular basis. That, by the way, is an understatement.

tolerance
Builds up rapidly with LSD. The same amount the next day gives a noticeably diminished effect. This wears off after three days to a week. There is also some cross-tolerance with other drugs of the same 'tryptamine' chemical family (magic mushrooms, DMT).