Though not an official diagnostic term, what are often called the positive symptoms of schizophrenia refer to abnormal features that are present (as opposed to absent).
Common positive symptoms of schizophrenia include:
- Hallucinations: These include sensory illusions, in any sensory modality, that can take the form of seeing, hearing, or tasting things that aren’t really there. Auditory hallucinations are more common than visual hallucinations.
- Delusions: Delusions are distorted beliefs that, despite possibly having a kernel of truth, are not supported by the overwhelming evidence accessible to most other objective, non-psychotic observers.
- Thought disorder symptoms: Thought disorders are a general category of dysfunctional features that highlight a person’s break from reality, or indicate their illogical thinking patterns, including loose associations (i.e., bizarre links between two events that are related in a person’s mind).
- Disorganized speech: Speech that does not make logical sense or is incoherent is often referred to as disorganized speech. This can possibly include nonsense syllables or the repetition of the same word or phrase over and over.
- Disorganized behavior: Disorganized behaviors do not fit a given situation, like undressing on a busy street corner.
- Movement symptoms: Disturbances in typical movement may either take the form of simple repetitive movements—like tics—or the lack of movement altogether (also called catatonia).