Some people believe that psychoanalysis has the medical model of treatment and cure. The social acceptance of analysis seems to be based on the idea that it can provide cures. If this is the case it is part of medicine.
In contrast, Lacan tried to introduce a break between psychoanalysis and medicine. He said that his theorization had nothing whatever to do with medicine or even with natural science. Psychoanalysis did not have as its goal curing patients; if people in analysis did get better, it was a welcome side-effect.