Two of the five main subtypes of schizophrenia are residual schizophrenia and undifferentiated schizophrenia. These two classifications are used when there is not enough information available on the symptoms to classify it as another subtype or when the symptoms are either severely diminished or gone altogether. Since this mental disorder is not something that can be cured the individual may have periods of severe symptoms along with periods when their condition is well controlled. If a diagnosis of undifferentiated is given that means that the symptoms do not clearly fit one of the other subtypes, and this may be true even if the symptoms have been stable over a long period of time. Many people may move from this category into one of the other subtypes, but some individuals will stay diagnosed as undifferentiated for many years.
Residual schizophrenia is a subtype that is completely different than undifferentiated schizophrenia. With the residual classification the individual is no longer showing prominent signs of schizophrenia symptoms, although some symptoms may linger but they are usually much less severe. Since this mental disorder can not be cured the goal is to treat the individual to keep any symptoms minimized so that a mostly normal life can be achieved. Those diagnosed with any type of schizophrenia will who have a higher functioning level before the onset will have a better outcome in general, as well as those who do not have structural abnormalities in their brain. A gradual onset that starts in childhood or adolescence, the presence of structural abnormalities in the brain, and an inability to come back after an acute episode all point to a less favorable outcome.