Catatonic behavior is a marked decrease in reactivity to the environment. This ranges from resistance to instructions (negativism); to maintaining a rigid, inappropriate or bi- zarre posture; to a complete lack of verbal and motor responses (mutism and stupor). It can excitement). Other features are repeated stereotyped movements, staring, grimacing, mutism, and the echoing of speech. Although catatonia has historically been associated with schizophrenia, catatonic symptoms are nonspecific and may occur in other mental disorders (e.g., bipolar or depressive disorders with catatonia) and in medical conditions (catatonic disorder due to another medical condition).
Negative symptoms account for a substantial portion of the morbidity associated with schizophrenia but are less prominent in other psychotic disorders. Two negative symp- toms are particularly prominent in schizophrenia: diminished emotional expression and avolition. Diminished emotional expression includes reductions in the expression of emo- tions in the face, eye contact, intonation of speech (prosody), and movements of the hand, head, and face that normally give an emotional emphasis to speech. Avolition is a decrease in motivated self-initiated purposeful activities. The individual may sit for long periods of time and show little interest in participating in work or social activities. Other negative symptoms include alogia, anhedonia, and asociality. Alogia is manifested by diminished speech output. Anhedonia is the decreased ability to experience pleasure from positive stimuli or a degradation in the recollection of pleasure previously experienced. Asociality refers to the apparent lack of interest in social interactions and may be associated with avo- lition, but it can also be a manifestation of limited opportunities for social interactions.
This chapter is organized along a gradient of psychopathology. Clinicians should first con- sider conditions that do not reach full criteria for a psychotic disorder or are limited to one domain of psychopathology. Then they should consider time-limited conditions. Finally, the diagnosis of a schizophrenia spectrum disorder requires the exclusion of another con- dition that may give rise to psychosis.
Schizotypal personality disorder is noted within this chapter as it is considered within the schizophrenia spectrum, although its full description is found in the chapter ”Person- ality Disorders.” The diagnosis schizotypal personality disorder captures a pervasive pat- tern of social and interpersonal deficits, including reduced capacity for close relationships; cognitive or perceptual distortions; and eccentricities of behavior, usually beginning by early adulthood but in some cases first becoming apparent in childhood and adolescence.
Abnormalities of beliefs, thinking, and perception are below the threshold for the diagno- sis of a psychotic disorder.
Two conditions are defined by abnormalities limited to one domain of psychosis: delu- sions or catatonia. Delusional disorder is characterized by at least 1 month of delusions but no other psychotic symptoms. Catatonia is described later in the chapter and further in this discussion.
Brief psychotic disorder lasts more than 1 day and remits by 1 month. Schizophreni- form disorder is characterized by a symptomatic presentation equivalent to that of schizo- phrenia except for its duration (less than 6 months) and the absence of a requirement for a decline in functioning.
Schizophrenia lasts for at least 6 months and includes at least 1 month of active-phase symptoms. In schizoaffective disorder, a mood episode and the active-phase symptoms of schizophrenia occur together and were preceded or are followed by at least 2 weeks of de- lusions or hallucinations without prominent mood symptoms.
Psychotic disorders may be induced by another condition. In substance/medication— induced psychotic disorder, the psychotic symptoms are judged to be a physiological con- sequence of a drug of abuse, a medication, or toxin exposure and cease after removal of the agent. In psychotic disorder due to another medical condition, the psychotic symptoms are judged to be a direct physiological consequence of another medical condition.