Thought disorders occur when a person’s use of language is presumed to reflect disordered thinking. People affected by thought disorders may speak incessantly and quickly, switch topics mid-sentence, or use rhyming or punning inappropriately or speak incoherently. The most common thought disorder is schizophrenia.


Schizophrenia is a chronic, severe and disabling brain disorder that has been recognized throughout recorded history and affects about 1 percent of Americans. People with schizophrenia may hear voices other people don’t hear, or they may believe that others are reading their minds, controlling their thoughts, or plotting to harm them. These experiences are terrifying and can cause fearfulness, withdrawal, or extreme agitation.

People with schizophrenia may not make sense when they talk, may sit for hours without moving or talking much, or may seem perfectly fine until they talk about what they are really thinking.

The symptoms of schizophrenia fall into three broad categories:

  • Positive symptoms are unusual thoughts or perceptions, including hallucinations, delusions, thought disorder, and disorders of movement.
  • Negative symptoms represent a loss or a decrease in the ability to initiate plans, speak, express emotion, or find pleasure in everyday life. These symptoms are harder to recognize as part of the disorder and can be mistaken for laziness or depression.
  • Cognitive symptoms (or cognitive deficits) are problems with attention, certain types of memory, and the executive functions that allow us to plan and organize. Cognitive deficits can also be difficult to recognize as part of the disorder but are the most disabling in terms of leading a normal life.

There are several different types of schizophrenia, each with its own defining characteristics:

Paranoid schizophrenia, in which a person feels extremely suspicious, persecuted or grandiose, or experiences a combination of these emotions.

Disorganized schizophrenia, in which a person is often incoherent but may not have delusions.

Catatonic schizophrenia, in which a person is withdrawn, mute and negative, and often assumes very unusual postures.

Residual schizophrenia, in which a person is no longer delusion or hallucinating, but has no motivation or interest in life. These symptoms can be most devastating.

People with schizophrenia are not especially prone to violence and often prefer to be left alone. Studies show that if people have no record of criminal violence before they develop schizophrenia and are not substance abusers, they are unlikely to commit crimes after they begin to experience symptoms. Most violent crimes are not committed by people with schizophrenia, and most people with schizophrenia do not commit violent crimes.

This information is not meant to replace professional advice, diagnosis or care from a licensed mental health practitioner; its sole intent is for education.

Only an experienced mental health professional can make an actual diagnosis. If you believe you may be suffering from one of these disorders, please consult a mental health professional.