A thought disorder is a mental health condition that affects a person’s beliefs, thoughts, or perceptions. Thought disorders alter the way a person puts together ordered sequences of ideas and can affect a person’s behavior by causing them to experience paranoia, delusions, hallucinations, or other symptoms.
Thought disorders are usually diagnosed when a person’s behavior or speaking indicates problematic, illogical, or incoherent patterns of thinking. Thinking normally involves three parts: thinking about something, stringing thoughts together on what you are thinking about, and, finally, the delivery or flow of a thought pattern. A thought disorder disrupts one or more aspects of the thought process.
A thought disorder is distinct from speech disorders, which occur as a result of difficulty with speech patterns and production, rather than an underlying problem with thought processes. Schizophrenia is a type of thought disorder, and delusions—false beliefs that a person persists in believing despite conflicting evidence—can also be caused by thought disorders.