Schizophrenia Spectrum and Other Psychotic Disorders 89
domain of psychopathology. Then they should  consider time-limited  conditions. Finally,
the diagnosis of a schizophrenia spectrum diso rder 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 pers onality disorder captures a pervasive pat-
tern of social and interpersonal deficits, including reduced capacity for close relationships;
cognitive or perceptual distor tions; and eccentricities of behavior, usually beginning by
early adulthood but in some cases first becoming apparent in childhood and adolescence.
Abnormalities of beliefs, thinki ng, 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 desc ribed 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 an d includes at least 1 month of active-phase
symptoms. In schizoaffective disorder, a mood episode and the active-phase symptoms of
schizophrenia occur together an d were preceded or are followe d by at least 2 weeks of de-