Usually with schizophrenia, the person's inner world and behavior change notably. Behavior changes might include the following:
Depersonalization (a sense of being unreal, hazy and in a dreamlike state), sometimes accompanied by intense anxiety
Loss of appetite
Loss of hygiene
Hallucinations (hearing or seeing things that aren't there)
The sense of being controlled by outside forces
A person with schizophrenia may not have any outward appearance of being ill. In other cases, the illness may be more apparent, causing bizarre behaviors. For example, a person with schizophrenia may wear aluminum foil in the belief that it will stop one's thoughts from being broadcast and protect against malicious waves entering the brain.
People with schizophrenia vary widely in their behavior as they struggle with an illness beyond their control. In active stages, those affected may ramble in illogical sentences or react with uncontrolled anger or violence to a perceived threat. People with schizophrenia may also experience relatively passive phases of the illness in which they seem to lack personality, movement, and emotion (also called a flat affect). People with schizophrenia may alternate in these extremes. Their behavior may or may not be predictable.
In order to better understand schizophrenia, the concept of clusters of symptoms is often used. Thus, people with schizophrenia can experience symptoms that may be grouped under the following categories:
Positive symptoms: Hearing voices, suspiciousness, feeling as though they are under constant surveillance, delusions, or making up words without a meaning (neologisms).
Negative (or deficit) symptoms: Social withdrawal, difficulty in expressing emotions (in extreme cases called blunted affect), difficulty in taking care of themselves, inability to feel pleasure. These symptoms cause severe impairment and are often mistaken for laziness.
Cognitive symptoms: Difficulties attending to and processing of information, understanding the environment, and remembering simple tasks.
Affective (or mood) symptoms: Most notably depression, accounting for a very high rate of attempted suicide in people suffering from schizophrenia. Anxiety can also be present and may be a direct result of the psychosis or come and go during a psychotic episode.
Helpful definitions in understanding schizophrenia include the following:
Psychosis: Psychosis is defined as being out of touch with reality. During this phase, one can experience delusions or prominent hallucinations. People with psychoses are not aware that what they are experiencing or some of the things that they believe are not real. Psychosis is a prominent feature of schizophrenia but is not unique to this illness.
Schizoid: This term is often used to describe a personality disorder characterized by almost complete lack of interest in social relationships and a restricted range of expression of emotions in interpersonal settings, making a person with this disorder appear cold and aloof.
Schizotypal: This term defines a personality disorder characterized by acute discomfort with close relationships as well as disturbances of perception, odd beliefs, and bizarre behaviors. Often individuals with schizotypal personality disorder are seen as odd and eccentric because of unusual mannerisms and beliefs.
Hallucinations: A person with schizophrenia may have strong sensations of objects or events that are real only to him or her. These may be in the form of things that they believe strongly that they see, hear, smell, taste, or touch. Hallucinations have no outside source, and are sometimes described as "the person's mind playing tricks" on him or her.
Illusion: An illusion is a mistaken perception for which there is an actual external stimulus. For example, a visual illusion might be seeing a shadow and misinterpreting it as a person. The words "illusion" and "hallucination" are sometimes confused with each other.
Delusion: A person with a delusion has a strong belief about something despite evidence that the belief is completely false. For instance, a person may listen to a radio and believe the radio is giving a coded message about an impending alien invasion. All of the other people who listen to the same radio program would hear, for example, a feature story about road repair work taking place in the area.
Types of schizophrenia include the following:
Paranoid-type schizophrenia is characterized by delusions and auditory hallucinations but relatively normal intellectual functioning and expression of affect. The delusions can often be about being persecuted unfairly or being some other person who is famous. People with paranoid-type schizophrenia can exhibit anger, aloofness, anxiety, and argumentativeness.
Disorganized-type schizophrenia is characterized by speech and behavior that are disorganized or difficult to understand and flattening, inappropriate, or exaggerated emotions. People with disorganized-type schizophrenia may laugh at the changing color of a traffic light or at something not closely related to what they are saying or doing. Their disorganized behavior may disrupt normal activities such as showering, dressing, and preparing meals.
Catatonic-type schizophrenia is characterized by disturbances of movement. People with catatonic-type schizophrenia may keep themselves completely immobile or move all over the place. They may not say anything for hours, or they may repeat anything you say or do senselessly. Either way, the behavior is putting these people at high risk because it impairs their ability to take care of themselves.
Undifferentiated-type schizophrenia is characterized by some symptoms seen in all of the above types but not enough of any one of them to define it as a particular type of schizophrenia.
Residual-type schizophrenia is characterized by a past history of at least one episode of schizophrenia, but the person currently has no prominent positive symptoms (delusions, hallucinations, disorganized speech or behavior). The individual still exhibits some negative symptoms such as lack of desire to develop relationships, flat emotional expression, limited speech, lack of motivation, and difficulty experiencing pleasure. It may represent a transition between a full-blown episode and complete remission. Or it may continue for years without any further psychotic episodes.