There are five types of symptoms characteristic of schizophrenia: delusions, hallucinations, disorganized speech, disorganized behavior, and the so-called “negative” symptoms. However, the signs and symptoms of schizophrenia vary dramatically from person to person, both in pattern and severity. Not every person with schizophrenia will have all symptoms, and the symptoms of schizophrenia may also change over time.
A delusion is a firmly-held idea that a person has despite clear and obvious evidence that it isn’t true. Delusions are extremely common in schizophrenia, occurring in more than 90% of those who have the disorder. Often, these delusions involve illogical or bizarre ideas or fantasies. Common schizophrenic delusions include:
Delusions of persecution – Belief that others, often a vague “they,” are out to get him or her. These persecutory delusions often involve bizarre ideas and plots (e.g. “Martians are trying to poison me with radioactive particles delivered through my tap water”).
Delusions of reference – A neutral environmental event is believed to have a special and personal meaning. For example, a person with schizophrenia might believe a billboard or a person on TV is sending a message meant specifically for them.
Delusions of grandeur – Belief that one is a famous or important figure, such as Jesus Christ or Napolean. Alternately, delusions of grandeur may involve the belief that one has unusual powers that no one else has (e.g. the ability to fly).
Delusions of control – Belief that one’s thoughts or actions are being controlled by outside, alien forces. Common delusions of control include thought broadcasting (“My private thoughts are being transmitted to others”), thought insertion (“Someone is planting thoughts in my head”), and thought withdrawal (“The CIA is robbing me of my thoughts”).
Hallucinations are sounds or other sensations experienced as real when they exist only in the persons mind. While hallucinations can involve any of the five senses, auditory hallucinations (e.g. hearing voices or some other sound) are most common in schizophrenia. Visual hallucinations are also relatively common. Research suggests that auditory hallucinations occur when people misinterpret their own inner self-talk as coming from an outside source.
Schizophrenic hallucinations are usually meaningful to the person experiencing them. Many times, the voices are those of someone they know. Most commonly, the voices are critical, vulgar, or abusive. Hallucinations also tend to be worse when the person is alone.
Fragmented thinking is characteristic of schizophrenia. Externally, it can be observed in the way a person speaks. People with schizophrenia tend to have trouble concentrating and maintaining a train of thought. They may respond to queries with an unrelated answer, start sentences with one topic and end somewhere completely different, speak incoherently, or say illogical things.
Common signs of disorganized speech in schizophrenia include:
Loose associations – Rapidly shifting from topic to topic, with no connection between one thought and the next.
Neologisms – Made-up words or phrases that only have meaning to the patient.
Perseveration – Repetition of words and statements; saying the same thing over and over.
Clang – Meaningless use of rhyming words (“I said the bread and read the shed and fed Ned at the head").
Schizophrenia disrupts goal-directed activity, causing impairments in a person’s ability to take care of him or herself, work, and interact with others. Disorganized behavior appears as:
A decline in overall daily functioning
Unpredictable or inappropriate emotional responses
Behaviors that appear bizarre and have no purpose
Lack of inhibition and impulse control
Negative symptoms (absence of normal behaviors)
The so-called “negative” symptoms of schizophrenia refer to the absence of normal behaviors found in healthy individuals. Common negative symptoms of schizophrenia include:
Lack of emotional expression – Inexpressive face, including a flat voice, lack of eye contact, and blank or restricted facial expressions.
Lack of interest or enthusiasm – Problems with motivation; lack of self-care.
Seeming lack of interest in the world – Apparent unawareness of the environment; social withdrawal.
Speech difficulties and abnormalities – Inability to carry a conversation; short and sometimes disconnected replies to questions; speaking in monotone.