At least two or more positive symptoms (termed positive because they indicate the presence of an—extreme or distorted version of—typical behavior), each present for at least 1 month. Delusions: Unusual, persistent and entrenched beliefs. Hallucinations: Sensations so vivid they seem real, although they are not. Scrambled speech: Thoughts appear disconnected, sentences are incoherent and words can be jumbled. Significantly disorganized or catatonic behavior: Difficulty with daily tasks such as planning a meal or daily hygiene and physical immobility. |
Some negative symptoms (termed negative because they indicate the absence of typical behavior), such as a failure to express or respond to emotion; slow, empty replies to questions; or an inability to initiate goal-directed behavior. |
Social and/or work-related dysfunction since the onset of symptoms. The functioning level since the onset of the symptoms is significantly below the prior level. |
| Source: Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, American Psychiatric Publishing, 2013. |