If you are found not guilty by reason of mental disease or defect, your case is not over.  Instead, a new set of proceedings will be held to determine your current mental health condition, whether you are a danger to yourself or the community, and whether you should be committed to a mental health facility.  If you are committed to a mental health facility, your mental health status will be addressed in regular intervals, but you could be held for longer than the maximum criminal sentence unless your mental health condition improves.