Schizophrenia is a mental condition that is characterized by dysfunctional perception of reality, with irregularities in the mood and manner of thinking. Some patients with schizophrenia do not exhibit normal expression in their faces, have monotonous voice, and seem to be apathetic. This is referred to as flat affect. Catatonic reaction refers to a motionless stupor and absence of any reaction to an external stimulus. Anhedonia is an inability to take pleasure in normally pleasurable things. Labile affect refers to an exaggerated show of emotions usually inappropriate to the situation.