Autistic catatonia is a rare type of disorder that affects roughly 10 percent of all adults with autism spectrum disorder. Most of them are not severely affected but a few exhibit stupor and severe excitement, which is the most extreme form of the disorder. Full expression of excitement could be a sign of comorbid Bipolar disorder but more research is needed. Childhood schizophrenia increases the risk for autistic catatonia later in life dramatically. There seems to be a common font of brain pathology for psychosis, catatonia and autism.