This disorder is similar to but milder than schizophrenia. To be diagnosed, a person must have 2 or more of the following symptoms for a significant part of the time during a 1-month or longer period:
- Delusions - fixed, mistaken ideas that the person holds. These are often odd or incorrect ideas about themselves and the world around them.
- Hallucinations - sensations that only the person experiences. This can include voices speaking to them that only they can hear.
- Disorganized Speech - this can be switching topics frequently while talking, giving answers to questions that weren't asked or not being understandable by others.
- Very Disorganized or Catatonic Behavior - this might be childlike "silliness" or being agitated or irritated without a reason, or showing no reactions to the world around them.
- Negative Symptoms - this might be not having the full range of emotional expression that others do, having poor eye contract and little body movement; or not showing interest in participating in activities.
Additional criteria include:
- the episode must last for at least 1 month, but less than 6 months.
- schizoaffective disorder and depressive or bipolar disorder with psychotic features have been ruled out.
- the symptoms are not the result of a substance/medication taken or another medical condition.