Diagnostic Parameter, Schizophrenia

Schizophrenia

A group of psychotic disorders characterized by disturbances in thought, perception, affect, behavior, and communication that last longer than 6 months.
Symptoms. For a material part of at least one month (or less, if effectively treated) the patient has had 2 or more of:

Delusions (only one symptom is required if a delusion is bizarre, such as being abducted in a space ship from the sun)

Hallucinations (only one symptom is required if hallucinations are of at least two voices talking to one another or of a voice that keeps up a running commentary on the patient's thoughts or actions).

Speech that shows incoherence, derailment or other disorganization

Severely disorganized or catatonic behavior Any negative symptom such as flat affect, reduced speech or lack of volition.

Duration. For at least 6 continuous months the patient has shown some evidence of the disorder. At least one month must include the symptoms of frank psychosis mentioned above. During the balance of this time (either as a prodrome or residual of the illness), the patient must show either or both:

Negative symptoms as mentioned above.

In attenuated form, at least 2 of the other symptoms mentioned above (example: deteriorating personal hygiene plus an increasing suspicion that people are talking behind one's back).
Dysfunction. For much of this time, the disorder has materially impaired the patient's ability to work, study, socialize or provide self-care.

Mood exclusions. Mood and schizoaffective disorders have been ruled out, because the duration of any depressive or manic episodes that have occurred during the psychotic phase has been brief.

Other exclusions. This disorder is not directly caused by a general medical condition or the use of substances, including prescription medications.

Developmental Disorder exclusion. If the patient has a history of any Pervasive Developmental Disorder (such as Autistic Disorder), only diagnose Schizophrenia if prominent hallucinations or delusions are also present for a month or more (less, if treated).

After at least 1 year as passed since onset, classify the course of psychosis. Until a year has passed, you cannot assign any of these course specifiers.

Continuous. There has been no remission of "A" symptoms (first bullet). If negative symptoms stand out, you can also add "With Prominent Negative Symptoms."

Episodic With Interepisode Residual Symptoms. During episodes, "A" criteria are met. Between episodes the patient has clinically important residual symptoms. If negative symptoms stand out, you can also add "With Prominent Negative Symptoms."

Episodic With No Interepisode Residual Symptoms. During episodes, "A" criteria are met. Between episodes the patient has remissions with no clinically important symptoms.

Single Episode in Partial Remission. There has been one episode during which "A" criteria are met. Now there are some clinically important residual symptoms. If negative symptoms stand out, you can also add "With Prominent Negative Symptoms."

Single Episode in Full Remission. No clinically important symptoms remain.

Other or Unspecified Pattern.
Clinical Types
| Paranoid Type | Disorganized Type | Catatonic Type | Undifferentiated Type | Residual Type |

Paranoid type

The patient meets the basic criteria for Schizophrenia.
The patient is preoccupied with delusions or frequent auditory hallucinations.

None of these symptoms is prominent:

Disorganized speech
Disorganized behavior
Inappropriate or flat affect
Catatonic behavior

Disorganized type

The patient meets the basic criteria for Schizophrenia
All of these symptoms are prominent:

Disorganized behavior
Disorganized speech
Affect that is flat or inappropriate
The patient does not fulfill criteria for Catatonic Schizophrenia

Catatonic Type

The patient meets the basic criteria for Schizophrenia
At least 2 catatonic symptoms predominate:

Stupor or motor immobility (catalepsy or waxy flexibility)
Hyperactivity that has no apparent purpose and is not influenced by external stimuli
Mutism or marked negativism
Peculiar behavior such as posturing, stereotypes, mannerisms or grimacing
Echolalia or echopraxia
Undifferentiated Type

The patient meets the basic criteria for Schizophrenia
The patient does not meet criteria for Paranoid, Disorganized, or Catatonic types.

Residual Type

The patient at one time met criteria for Catatonic, Disorganized, Paranoid or Undifferentiated Schizophrenia.
The patient no longer has pronounced catatonic behavior, delusions, hallucinations or disorganized speech or behavior.

The patient is still ill, as indicated by either:

1) Negative symptoms such as flattened affect, reduced speech output or lack of volition, or

2) An attenuated form of at least 2 characteristic symptoms of schizophrenia, such as odd beliefs (related to delusions), distorted perceptions or illusions (hallucinations), odd speech (disorganized speech) or peculiarities of behavior (disorganized behavior).