Signs and Symptoms of Schizophrenia

People with schizophrenia usually have a history of acute psychosis. Psychosis is a disturbance of mental health that is severe enough to cause a change in normal personality, normal emotional balance, as well as detachment from reality. Psychoses occur with and without external cause. In schizophrenia, they occur without external cause, without gross changes in cerebral structure.

Symptoms of schizophrenia include the following:

  • Hallucinations—false visual, auditory, or tactile perceptions without a realistic basis or external cause
  • Delusions—exaggerated or distorted thoughts and perceptions of self and others; or unrealistic belief in ability, knowledge, or ideas
  • Disorganized thought—including nonsensical associations and disorganized speech
  • Disorganized behavior—including aggressiveness and wild gestures
  • Difficulty showing or expressing emotion—including flattened behavior (rigid posture, inability to move or talk, unresponsiveness)

Hallucinations can pertain to any of the senses, but auditory hallucinations are the most common in schizophrenia. It is especially common for people with schizophrenia to hear voices, which are usually insidious and threatening. These voices, which are sometimes familiar and other times unknown, are always identified as separate from the person's own voice.

These hallucinations can include several voices that comment continually on the person's behavior. Hypnogogic and hypnopompic hallucinations, those normally experienced while falling asleep and waking up, are not associated with schizophrenia.

Delusions common in schizophrenia, like schizophrenic hallucinations, are characteristically antagonistic and threatening. For example, delusions of persecution, which cause paranoia, are most common. People may claim that they are being harassed, followed, and provoked or that they are victims of conspiracy.

Delusions that are unbelievable or fantastic are referred to as bizarre. For example, people have delusions of repeated alien contact, or that someone has read their mind and either stolen or replaced their thoughts-things for which there is no established truth.

Disorganized thinking and speech is considered by some to be the defining symptom of schizophrenia. It often results in severely impaired communication. Mild disorganization may cause people with schizophrenia to switch subjects during a conversation. Moderately impaired thinking may result in speech that is vaguely or loosely related. Severely disorganized thinking often results in "word salad," or incoherent and incomprehensible speech.

Occasional confusion and disorganization is normal for most people. In schizophrenia, however, the degree of confusion and disorganization significantly reduces or destroys a person's ability to communicate.

Disorganized and bizarre behavior that is aggressive, childlike, exaggerated, emotive, or socially unacceptable is another definitive symptom of schizophrenia. Unprovoked shouting, public exhibition, and constant irritation are common examples.

Appearance-based behaviors constitute a significant portion of the spectrum. For example, people with schizophrenia have been known to routinely wear many layers of clothing, regardless of the weather. They may be disheveled or extremely dirty.

Disorganized behavior is not goal driven; that is, the person does intend to behave a certain way. This differs from delusional behavior, in which delusions motivate a person's behavior.

Disorganized thinking and behavior are often called the disorganized symptom cluster. Generally, the symptoms in the cluster demonstrate meaningless behavior and a loss of intention. Because these symptoms are common to other mental disorders and illnesses (in varying intensity), extended observation is critical for a diagnosis of schizophrenia.

Flattened affect is the clinical term for the emotionless state that is common in schizophrenia. People with schizophrenia often do not express emotion and may appear unaffected, distant, or unresponsive. Although flattened affect is found in other mental disorders, it is especially common in schizophrenia.

People with catatonia often do not respond to their environment. Their eye contact, facial expression, attention span, and body language are typically absent or significantly diminished. They may become rigid and resist being touched or moved. Catatonic stupor may precede an excited phase during which the person suddenly exhibits increased agitation or aggression.

Schizophrenia is sometimes classified according to the predominance of certain symptoms. For example, paranoid schizophrenia typically features delusions and hallucinations without disorganized speech, while the disorganized type mainly features inappropriate behavior instead of diminished emotion.

The deterioration of function is probably the most important symptom of the disorder. Major areas of dysfunction include the following:

  • Interpersonal relationships
  • School (i.e., for children, especially)
  • Self-care
  • Work

People with schizophrenia typically have a hard time keeping a job. Some people have been known to switch jobs or to get fired several times a month. Many work at lower level jobs than their parents. They often earn less money and make fewer advances, instead of surpassing their parents' socioeconomic level. The ability to form and maintain relationships is usually hindered, in both social and occupational settings. About 65 percent of people with schizophrenia never marry. Personal hygiene and physical health often decline, too.

Teenagers may experience difficulty in school, as their attention span dissolves and their thinking becomes impaired. As their peers are developing new skills and new ways of thinking, children with schizophrenia may lack the ability to think abstractly and to solve problems.

Publication Review By: the Editorial Staff at

Published: 31 Jan 2001

Last Modified: 02 Oct 2015