Schizophrenia and other psychotic disorders
Schizophrenia and Other Psychotic Disorders
The disorders in this section include Schizophrenia, Schizophreniform Disorder, Schizoaffective Disorder, Delusional Disorder, Brief Psychotic Disorder, Shared Psychotic Disorder, Psychotic Disorder Due to a General Medical Condition, Substance-Induced Psychotic Disorder, and Psychotic Disorder Not Otherwise Specified. These disorders have been grouped together to facilitate the differential diagnosis of disorders that include psychotic symptoms as a prominent aspect of their presentation. Other disorders that may present with psychotic symptoms as associated features are included elsewhere in the manual (e.g., Dementia of the Alzheimer's Type and Substance-Induced Delirium in the "Delirium, Dementia, and Amnestic and Other Cognitive Disorders" section; Major Depressive Disorder, With Psychotic Features, in the "Mood Disorders" section). Despite the fact that these disorders are grouped together in this chapter, it should be understood that psychotic symptoms are not necessarily considered to be core or fundamental features of these disorders, nor do the disorders in this section necessarily have a common etiology. In fact, a number of studies suggest closer etiological associations between Schizophrenia and other disorders that, by definition, do not present with psychotic symptoms (e.g., Schizotypal Personality Disorder).
The term psychotic has historically received a number of different definitions, none of which has achieved universal acceptance. The narrowest definition of psychotic is restricted to delusions or prominent hallucinations, with the hallucinations occurring in the absence of insight into their pathological nature. A slightly less restrictive definition would also include prominent hallucinations that the individual realizes are hallucinatory experiences. Broader still is a definition that also includes other positive symptoms of Schizophrenia (i.e., disorganized speech, grossly disorganized or catatonic behavior). Unlike these definitions based on symptoms, the definition used in earlier classifications (e.g., DSM-II and ICD-9) was probably far too inclusive and focused on the severity of functional impairment. In that context, a mental disorder was termed "psychotic" if it resulted in "impairment that grossly interferes with the capacity to meet ordinary demands of life." The term has also previously been defined as a "loss of ego boundaries" or a "gross impairment in reality testing."
In this manual, the term psychotic refers to the presence of certain symptoms. However, the specific constellation of symptoms to which the term refers varies to some extent across the diagnostic categories. In Schizophrenia, Schizophreniform Disorder, Schizoaffective Disorder, and Brief Psychotic Disorder, the term psychotic refers to delusions, any prominent hallucinations, disorganized speech, or disorganized or catatonic behavior. In Psychotic Disorder Due to a General Medical Condition and in Substance-Induced Psychotic Disorder, psychotic refers to delusions or only those hallucinations that are not accompanied by insight. Finally, in Delusional Disorder and Shared Psychotic Disorder, psychotic is equivalent to delusional.
The following disorders are included in this section:
- Schizophrenia is a disorder that lasts for at least 6 months and includes at least 1 month of active-phase symptoms (i.e., two [or more] of the following: delusions, hallucinations, disorganized speech, grossly disorganized or catatonic behavior, negative symptoms). Definitions for the Schizophrenia subtypes (Paranoid, Disorganized, Catatonic, Undifferentiated, and Residual) are also included in this section.
- Schizophreniform Disorder is characterized by a symptomatic presentation that is equivalent to Schizophrenia except for its duration (i.e., the disturbance lasts from 1 to 6 months) and the absence of a requirement that there be a decline in functioning.
- Schizoaffective Disorder is a disorder in which a mood episode and the active-phase symptoms of Schizophrenia occur together and were preceded or are followed by at least 2 weeks of delusions or hallucinations without prominent mood symptoms.
- Delusional Disorder is characterized by at least 1 month of nonbizarre delusions without other active-phase symptoms of Schizophrenia.
- Brief Psychotic Disorder is a disorder that lasts more than 1 day and remits by 1 month.
- Shared Psychotic Disorder is characterized by the presence of a delusion in an individual who is influenced by someone else who has a longer-standing delusion with similar content.
In Psychotic Disorder Due to a General Medical Condition, the psychotic symptoms are judged to be a direct physiological consequence of a general medical condition.
In Substance-Induced Psychotic Disorder, the psychotic symptoms are judged to be a direct physiological consequence of a drug of abuse, a medication, or toxin exposure.
Psychotic Disorder Not Otherwise Specified is included for classifying psychotic presentations that do not meet the criteria for any of the specific Psychotic Disorders defined in this section or psychotic symptomatology about which there is inadequate or contradictory information.