Schizophrenia (DSM-IV-R)

DIAGNOSTIC CRITERIA FOR SCHIZOPHRENIA

A. Characteristic Symptoms: Two (or more) of the following, each present for a significant portion of time during a 1-month period (or less if successfully treated):

  1. delusions
  2. hallucinations
  3. disorganized Speech (e.g., frequent derailment or incoherence)
  4. grossly disorganized or catatonic behavior
  5. negative symptoms, i.e., affective flattening, alongia, or avolition

Note: Only one Criterion A symptom is required if delusions are bizarre or hallucinations consist of a voice keeping up a running commentary on the person's behavior or thoughts, or two or more voices conversing with each other.

 

B. Social/Occupational dysfunction: For a significant portion of the time since the onset of the disturbance, one or more major areas of functioning such as work, interpersonal relations, or self-care are markedly below the level achieved prior to the onset (or when the onset is in childhood or adolescence, failure to achieve expected level of interpersonal, academic, or occupational achievement).

 

C. Duration: Continuous signs of the disturbance persist for at least 6 months.  This 6 month period must include at least 1 month of symptoms (or less if successfully treated) that meet Criterion A (i.e., active-phase symptoms) and may include periods of prodromal or residual symptoms.  During these prodromal or residual periods, the signs of the disturbance may be manifested by only negative symptoms or two or more symptoms listed in Criterion A present in an attenuated form (e.g., odd beliefs, unusual perceptual experiences).

 

D. Schizoaffective and Mood Disorder exclusion: Schizoaffective Disorder and Mood Disorder with Psychotic Features have been ruled out because either (1) no Major Depressive, Manic, or Mixed Episodes have occurred concurrently with the active-phase symptoms; or (2) if mood episodes have occurred during active-phase symptoms, their total duration has been brief relative to the duration of the active and residual periods.

 

E. Substance/General Medical Condition exclusion: The disturbance is not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication) or a general medical condition.

 

F. Relationship to a Pervasive Developmental Disorder: If there is a history of Autistic Disorder or another Pervasive Developmental Disorder, the additional diagnosis of Schizophrenia is made only if prominent delusions or hallucinations are also present for at least a month (or less if successfully treated).

 


DIAGNOSTIC FEATURES

The essential features of Schizophrenia are a mixture of characteristic signs and symptoms (both positive and negative) that have been present for a significant portion of time during a 1-month period (or for a shorter time if successfully treated), with some signs of the disorder persisting for at least 6 months.  These signs and symptoms are associated with marked social or occupational dysfunction.  The disturbance is not better accounted for by Schizoaffected Disorder or a Mood Disorder with Psychotic Features and is not due to the direct physiological effects of a substance or a general medical condition.  In individuals with a previous diagnosis of Autistic Disorder (or another Pervasive Developmental Disorder), the additional diagnosis of Schizophrenia is warranted only if prominent delusions or hallucinations are present for at least a month.


The characteristic symptoms of Schizophrenia involve a range of cognitive and emotional dysfunctions that include perception, inferential thinking, language and communication, behavioral monitoring, affect, fluency and productivity of thought and speech, hedonic capacity, volition and drive, and attention.  No single symptom is pathognomonic of Schizophrenia; the diagnosis involves the recognition of a constellation of signs and symptoms associated with impaired occupational or social functioning.

 

Characteristic symptoms may be conceptualized as falling into two broad categories: positive and negative.  The positive symptoms appear to reflect an excess or distortion of normal functions, whereas the negative symptoms appear to reflect a diminution or loss of normal functions.  The positive symptoms include distortions in thought content (delusions), perception (hallucinations), language and thought process (disorganized speech), and self-monitoring of behavior (grossly disorganized or catatonic behavior).  These positive symptoms may comprise two distinct dimensions, which may in turn be related to different underlying neural mechanisms and clinical correlates.  The "psychotic dimension" includes delusions and hallucinations, whereas the "disorganization dimension" includes disorganized speech and behavior.  Negative symptoms include restrictions in the range and intensity of emotional expression (affective flattening), in the fluency and productivity of thought and speech (alogia), and in the initiation of goal-directed behavior (avolition).

 

Delusions are erroneous beliefs that usually involve a misinterpretation of perceptions or experiences.  Their content may include a variety of themes (e.g., persecutory, referential, somatic, religious, or grandiose).  Persecutory delusions are most common; the person believes he or she is being tormented, followed, tricked, spied on, or ridiculed.  Referential delusions are also common; the person believes that certain gestures, comments, passages from books, newspapers, song lyrics, or other environmental cues are specifically directed at him or her.  The distinction between a delusion and a strongly held idea is sometimes difficult to make and depends in part on the degree of conviction with which the belief is held despite clear contradictory evidence regarding its veracity.

 


POSITIVE SYMPTOMS OF SCHIZOPHRENIA

Positive symptoms of Schizophrenia appear to reflect an excess or distortion of normal functions and include the following:

  1. Delusions: Although bizarre delusions are considered to be especially characteristic of Schizophrenia, "bizarreness" may be difficult to judge, especially across different cultures. Delusions are deemed bizarre if they are clearly implausible and not understandable and do not derive from ordinary life experiences. An example of a bizarre delusion is a person's belief that a stranger has removed his or her internal organs and has replaced them with someone else's organs without leaving any wounds or scars. An example of a non-bizarre delusion is a person's false belief that he or she is under surveillance by the police. Delusions that express a loss of control over mind or body are generally considered to be bizarre; these include a person's belief that his or her thought have been taken away by some outside force, that alien thoughts have been put into his or her mind, or that his or her body or actions are being acted on or manipulated by some outside force. If the delusions are judged to be bizarre, only this single symptom is needed to satisfy Criterion A (noted above) for Schizophrenia.
  2. Hallucinations: Hallucinations may occur in any sensory modality (e.g., auditory, visual, olfactory, gustatory, and tactile), but auditory hallucinations are by far the most common. Auditory hallucinations are usually experienced as voices, whether familiar or unfamiliar, that are perceived as distinct from the person's own thoughts. The hallucinations must occur in the context of a clear sensorium; those that occur while falling asleep (hypnagogic) or waking up (hypnopompic) are considered to be within the range of normal experience. Isolated experiences of hearing one's name called or experiences that lack the quality of an external percept (e.g., a humming in one's head) should also not be considered as symptomatic of Schizophrenia or any other Psychotic Disorder. Hallucinations may be a normal part of religious experience in certain cultural context. Certain types of auditory hallucinations (i.e., two or more voices conversing with one another or voices maintaining a running commentary on the person's thoughts or behavior) have been considered to be particularly characteristic of Schizophrenia. If these types of hallucinations are present, then only this single symptom is needed to satisfy Criterion A.
  3. Disorganized Thinking: Disorganized Thinking "Formal Thought Disorder" has been argued by some to be the single most important feature of Schizophrenia. Because of the difficulty inherent in developing an objective definition of "thought disorder," and because in a clinical setting inferences about thought are based primarily on the individual's speech, the concept of disorganized speech has been emphasized in the definition for Schizophrenia. The speech of individuals with Schizophrenia may be disorganized in a variety of ways. the person may "slip off the track" from one topic to another ("derailment" or "loose associations"); answers to questions may be obliquely related or completely unrelated ("trangentiality"); and, rarely, speech may be so severely disorganized that it is nearly incomprehensible and resembles receptive aphasia in its linguistic disorganization ("incoherence" or "word salad"). Because mildly disorganized speech is common and nonspecific, the symptom must be severe enough to substantially impair effective communication. Less severe disorganized thinking or speech may occur during the prodromal and residual periods of Schizophrenia.
  4. Grossly Disorganized Behavior: Grossly Disorganized Behavior may manifest itself in a variety of ways, ranging from childlike silliness to unpredictable agitation. Problems may be noted in any form of goal-directed behavior, leading to difficulties in performing activities of daily living such as preparing a meal or maintaining hygiene. The person may appear markedly disheveled, may dress in an unusual manner (i.e., wearing multiple overcoats, scarves, and gloves on a hot day), or may display clearly inappropriate sexual behavior (e.g., public masturbation) or unpredictable and untriggered agitation (e.g., shouting or swearing). Care should be taken not to apply this criterion too broadly. For example, a few instances of restless, angry, or agitated behavior should not be considered the be evidence of Schizophrenia, especially if the motivation is understandable.
  5. Grossly Disorganized Behavior: Grossly Disorganized Behavior may manifest itself in a variety of ways, ranging from childlike silliness to unpredictable agitation. Problems may be noted in any form of goal-directed behavior, leading to difficulties in performing activities of daily living such as preparing a meal or maintaining hygiene. The person may appear markedly disheveled, may dress in an unusual manner (i.e., wearing multiple overcoats, scarves, and gloves on a hot day), or may display clearly inappropriate sexual behavior (e.g., public masturbation) or unpredictable and untriggered agitation (e.g., shouting or swearing). Care should be taken not to apply this criterion too broadly. For example, a few instances of restless, angry, or agitated behavior should not be considered the be evidence of Schizophrenia, especially if the motivation is understandable.
  6. Catatonic Motor Behaviors: Catatonic Motor Behaviors include a marked decrease in reactivity to the environment, sometimes reaching an extreme degree of complete unawareness (catatonic stupor), maintaining a rigid posture and resisting efforts to be moved (catatonic negativism), the assumption of inappropriate or bizarre postures (catatonic posturing), or purposeless and unstimulated excessive motor activity(catatonic excitement).

 

 

NEGATIVE SYMPTOMS

The negative symptoms of Schizophrenia account for a substantial degree of the morbidity associated with the disorder.  Three negative symptoms are included in the definition of Schizophrenia.

  1. Affective Flattening:  Affective flattening is especially common and is characterized by the person's face appearing immobile and unresponsive, with poor eye contact and reduced body language.  Although a person with affective flattening may smile and warm up occasionally, his or her range of emotional expressiveness is clearly diminished most of the time. It may be useful to observe the person interacting with peers to determine whether affective flattening is sufficiently persistent to meet the criteria above. 
  2. Alogia (Poverty of Speech): Alogia is manifested  by brief, laconic, empty replies.  The individual with alogia appears to have a diminution of thoughts that is reflected in decreased fluency and productivity of speech.  This must be differentiated from an unwillingness to speak, a clinical judgement that may require observation over time and in a variety of situations.
  3. Avolition: Avolition is characterized by an inability to initiate and persist in goal-directed activities.  The person may sit for long periods of time and show little interest in participating in work or social activities.

* Although common in Schizophrenia, negative symptoms are difficult to evaluate because they occur on a continuum with normality, are relatively nonspecific, and may be due to a variety of other factors (including positive symptoms medication side effects, depression, environmental understimulation, or demoralization).  If a negative symptom is to be judged to be clearly attributable to any of these factors, then it should not be considered in making the diagnosis of Schizophrenia.

 


COURSE

Schizophrenia involves dysfunction in one or more major areas of functioning (e.g., interpersonal relations, work or education, or self-care).  Typically, functioning is clearly below that which had been archieved before the onset of symptoms.  If the disturbance begins in childhood or adolescence, however, there may be a failure to achieve what would have been expected for the individual rather than a deterioration in functioning.  Comparing the individual with unaffected siblings may be helpful in making this determinatino.  Educational progress is frequently disrupted, and the individual may be unable to finish school.  Many individuals are unable to hold a job for sustained periods of time and are employed at a lower level than their parents.  The majority (60%-70%) of individuals with Schizophrenia do not marry, and most have relatively limited social contacts.  The dysfunction persists for a substantial period during teh course of the disorder and does not appear to be a direct result of any single feature.  Some signs of the disturbance must persist for a continuous period of at least 6 months.  During that time period, there must be at least 1 month of symptoms (or less than 1 month if symptoms are successfully treated).