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Psychological Disorders


Substance-Related Disorders

Schizophrenia, page 2

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Schizophrenia is one of several psychotic disorders described in the DSM. People with psychotic disorders lose contact with reality and often have delusions or hallucinations. People with schizophrenia have a wide range of symptoms, which can be classified into positive or negative symptoms.

Positive Symptoms

Positive symptoms involve the presence of altered behaviors. Examples of positive symptoms include delusions, hallucinations, disorganized speech, and disorganized behavior. Delusions are false beliefs that are strongly held despite contradictory evidence. Hallucinations are sensory or perceptual experiences that happen without any external stimulus. Hallucinations can occur in any sensory modality, but auditory hallucinations are most common in schizophrenia. Disorganized speech can also take many forms. For example, a person with schizophrenia may produce word salad, which consists of words and sentences strung together in an incoherent way. Examples of disorganized behavior include inappropriate gestures or laughter, agitated pacing, or unpredictable violence.

Negative Symptoms

Negative symptoms involve an absence or reduction of normal behavior. Negative symptoms include emotional flatness, social withdrawal, spare or uninflected speech, and lack of motivation.

Subtypes of Schizophrenia

Schizophrenia is classified into four subtypes, depending on the symptoms present at the time of evaluation:

  1. Paranoid type: Characterized by marked delusions or hallucinations and relatively normal cognitive and emotional functioning. Delusions are usually persecutory, grandiose, or both. Persecutory delusions involve a belief that one is being oppressed, pursued, or harassed in some way. Grandiose delusions involve the belief that one is very important or famous. This subtype usually happens later in life than the other subtypes. Prognosis may also be better for this subtype than for other subtypes.
  2. Disorganized type: Characterized by disorganized behavior, disorganized speech, and emotional flatness or inappropriateness.
  3. Catatonic type: Characterized by unnatural movement patterns such as rigid, unmoving posture or continual, purposeless movements, or by unnatural speech patterns such as absence of speech or parroting of other people’s speech.
  4. Undifferentiated type: Diagnosis given to a patient that does not meet criteria for paranoid, disorganized, or catatonic schizophrenia.

Etiology of Schizophrenia

As with other psychological disorders, researchers have studied the etiology of schizophrenia from different perspectives.

Biological Factors

Research suggests that genes, neurotransmitters, and brain abnormalities play a role in the onset of schizophrenia:

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