Other disorders are related to, but distinguished from,
schizophrenia in terms of presenting symptoms and the duration or magnitude of
impairment. The DSM-IV-TR (APA, 2000)
categorizes these disorders as follows:
Schizophreniform disorder: The client exhibits the
symp-toms of schizophrenia but for less than the 6 months necessary to meet the
diagnostic criteria for schizophre-nia. Social or occupational functioning may
or may not be impaired.
Delusional disorder: The client has one or more
nonbi-zarre delusions—that is, the focus of the delusion is be-lievable.
Psychosocial functioning is not markedly impaired, and behavior is not
obviously odd or bizarre.
Brief psychotic disorder: The client experiences the
sud-den onset of at least one psychotic symptom, such as delusions,
hallucinations, or disorganized speech or be-havior, which lasts from 1 day to
1 month. The episode may or may not have an identifiable stressor or may
Shared psychotic disorder (folie à deux): Two people share a similar delusion. The person
with this diagnosis develops this delusion in the context of a close
relation-ship with someone who has psychotic delusions.
Two other diagnoses, schizoid personality disorder and schizotypal
personality disorder, are not psychotic disor-ders and should not be confused
with schizophrenia even though the names sound similar.