Symptoms
Usually with schizophrenia, the person's inner world and behavior change notably. Behavior changes might include the following: * Social withdrawal * Depersonalization (intense anxiety and a feeling of being unreal) * Loss of appetite * Loss of hygiene * Delusions * 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 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, in understanding the environment, and in remembering simple tasks. Affective (or mood) symptoms: Most notably depression, accounting for a very high rate of attempted suicide in people suffering from schizophrenia.
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 more severe personality disorder characterized by acute discomfort with close relationships as well as disturbances of perception and bizarre behaviors, making people with schizophrenia seem odd and eccentric because of unusual mannerisms. 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