Key Terms

anosognosia

not having insight or awareness into disease

auditory hallucination

altered perception of hearing in the absence of external stimuli

bizarre delusion

fixed false beliefs with content that is not reasonably possible in this world

cognitive symptoms

deficits in ability to think or reason

delusion

fixed false belief that cannot be changed in the mind of those who hold them despite evidence to the contrary

formication

hallucination that bugs are crawling on the skin

gustatory hallucination

false perception involving taste

hallucination

perception of sensory experiences without natural external stimuli, including auditory, visual, tactile, gustatory, and olfactory types

negative symptoms

“take away” from a person’s personality, including cognitive decline and apathy

non-bizarre delusion

fixed false belief containing content that is plausible but inconsistent with evidence

olfactory hallucination

false sensory experience involving the sense of smell

positive symptoms

changes to behaviors or content of thought, or the presence of symptoms, including hallucinations and delusions

psychosis

severe mental condition where a person loses the ability to recognize reality or has lost contact with external reality, causing a loss of function and disorganization of personality

schizophrenia

severe mental illness and disturbance involving a collection of cognitive, affective, and behavioral symptoms that negatively impact social, educational, or occupational functioning

tactile hallucination

false sensory perceptions involving the sense of touch

visual hallucination

false sensory experience that is seen