There are five recognized types of schizophrenia:

• Paranoid. Characterized by delusions (fixed false beliefs held by a person despite evidence to the contrary) in addition to other symptoms of schizophrenia, such as abnormal ways of thinking, and/or hallucinations. Typically, the onset of the disorder is later than with other types of schizophrenia, with some studies reporting an average age of 35 years. The complex of symptoms makes this paranoid schizophrenia -- if the only symptom is delusions, it is a delusional disorder, not paranoid schizophrenia.
  
  
• Disorganized. Characterized by disorganized behavior and speech. Expressions of emotion are often flat or inappropriate. Patients with this type of schizophrenia often deteriorate rapidly, talk gibberish and neglect personal hygiene and appearance. Frequently everything about their lives become disorganized.
  
  
• Catatonic. Characterized by abnormal physical movements. Although some patients may exhibit motor (motion) activity that is speeded up, most patients exhibit slow motor activity, sometimes to the point of stupor. This type of schizophrenia may also be marked by negativism or peculiar behavior such as posturing (maintaining an unusual or awkward posture for a long period of time).
  
  
• Undifferentiated. Patients who have been diagnosed with schizophrenia, but do not meet the characteristics of the paranoid, disorganized or catatonic types.
  
  
• Residual. Patients who were previously diagnosed with schizophrenia but are no longer experiencing positive symptoms, such as catatonic behavior, delusions, hallucinations or disorganized speech or behavior. However, patients still experience some symptoms of mental illness, such as flat expressions of emotion, reduced speech output or lack of volition (capability of conscious choice, decision and intention).

There are also two conditions related to schizophrenia:

• Schizophreniform disorder. This condition has similar symptoms except that they last from one to six months, compared to at least six months for schizophrenia, and it does not necessarily involve a decline in functioning. However, for many people the diagnosis of schizophreniform disorder represents a prodrome (beginning) stage of schizophrenia.
  
  
• Schizoaffective disorder. Patients with this condition exhibit signs of schizophrenia as well as mood disorders such as depression or mania. Because the diagnosis is not clearly schizophrenia, but also does not have all the symptoms needed to diagnose a depression, anxiety disorder or bipolar disorder, it falls into this category.