negative symptoms predominate presentation. This is
followed after a period of months or even years by a
period of acute exacerbation (the active phase) lasting
a month or longer, during which positive and disorga-
nization symptoms predominate. In the majority
(about 80%) of cases the course is chronic, character-
ized by at least some persistent negative symptoms
(the residual phase) as well as the occasional recur-
rence of positive or disorganization symptoms. The
total duration of symptoms (prodromal plus active
plus residual phases) should be at least 6 months. The
symptoms should occur in the absence of prominent
symptoms of depression or mania and should not be
the result of substance intoxication or withdrawal or
of general medical conditions. A number of com-
monly occurring subtypes of schizophrenia have been
identified based on their primary symptomatology,
including Paranoid Type (prominent delusions or hal-
lucinations), Catatonic Type (prominent disturbances
of volition), Disorganized Type (prominent disorgani-
zation symptoms), Residual Type (prominent negative
symptoms), and Undifferentiated Type (doesn’t fit one
of the other types). Age of onset is typically between
15 and 45 years; onset is about 5 years earlier in males
than in females. Schizophrenia can have a debilitating
affect on social adjustment, including impaired occu-
pational functioning; failure to establish intimate rela-
tionships and reduced fertility; increased mortality
owing to suicide, accident, and illness; and elevated
risk of serious violence. In about 50% of cases, there
is little or no improvement in social adjustment over
time; in about 30%, there is substantial improvement;
and in about 20%, there is good recovery or remission.
Good prognosis is associated with having achieved
adequate social functioning prior to onset of the disor-
der (e.g., absence of premorbid personality disorder),
acute onset (e.g., short prodromal phase, onset follow-
ing experience of a major life stressor), the presence
of abnormal affect (e.g., stormy affect, perplexity,
confusion), the absence of blunted or flat affect, and
the absence of a family history of schizophrenia. Early
detection and treatment may also be associated with
good prognosis.Schizophreniform Disorder. This differs from schizo-
phrenia only with respect to its course. Whereas the
total duration of symptoms in schizophrenia is at least
6 months, in schizophreniform disorder it is at least
1 month but less than 6 months. Two subtypes are rec-
ognized, With or Without Good Prognostic Features;
the former may be associated with a full return topremorbid social functioning, whereas the latter may
develop into full-blown schizophrenia (if psychotic
symptoms persist or recur).Brief Psychotic Disorder. This differs from schizophre-
nia and schizophreniform disorder in that the total dura-
tion of symptoms for all phases is less than 1 month,
followed by a full return to premorbid social and occu-
pational functioning. Three subtypes are recognized:
Two subtypes, With and Without Marked Stressors, are
diagnosed according to whether symptom onset occurs
shortly after and apparently in response to stressful life
events; the third, With Postpartum Onset, is diagnosed
in women when symptom onset occurs within 4 weeks
of giving birth.Schizoaffective Disorder. This differs from schizo-
phrenia only in that at some point during the active
phase of the illness, the person also suffers from
prominent symptoms of depression or mania (i.e.,
meets criteria for a major depressive, manic, or mixed
episode) but has had a period of at least 2 weeks in
which delusions or hallucinations were present in the
absence of mood symptoms. Two subtypes are recog-
nized, based on the nature of the mood symptoms:
Bipolar Type, if the mood disturbance includes at least
some symptoms of mania, and Depressive Type, if the
mood disturbance is limited to symptoms of depres-
sion. Schizoaffective disorder is associated with a bet-
ter long-term prognosis than schizophrenia, although
with a worse prognosis than mood disorders such as
major depressive disorder or bipolar I disorder.Delusional Disorder. This is characterized by promi-
nent nonbizarre delusions that persist for at least 1
month. The person may also exhibit prominent olfac-
tory or tactile hallucinations related to the content of
the delusions. The delusions should occur in the
absence of prominent auditory or visual hallucinations
and the absence of prominent mood symptoms, and
they should not be the result of substance intoxication
or withdrawal or of general medical conditions. Seven
subtypes are recognized, based on the predominant
theme of the delusions: Erotomanic, Grandiose,
Jealous, Persecutory, Somatic, Mixed, and Unspecified
Type. Delusional disorder may cause only limited or
restricted disturbance of psychosocial functioning.Shared Psychotic Disorder. This is diagnosed when
the person develops delusions similar to those exhibited
by a close acquaintance who suffers from a psychotic652 ———Psychotic DisordersP-Cutler (Encyc)-45463.qxd 11/18/2007 12:43 PM Page 652