110 Schizophrenia Spectrum and Other Psychotic Disorders
depressive or bipolar disorder with psychoti c features. More specifically, schizoaffective
disorder can be distinguished from a depressive or bipolar disorder with psychotic features
based on the presence of prom inent delusions and/or hallucinations for at least 2 weeks in
the absence of a major mood episode. In cont rast, in depressive or bipolar disorder with
psychotic features, the psychoti c features primarily occur duri ng the mood episode(s). Be-
cause the relative proportion of mood to ps ychotic symptoms may change over time, the
appropriate diagnosis may change from and to  schizoaffective disorder. (For example, a
diagnosis of schizoaffective disorder for a se vere and prominent major depressive episode
lasting 3 months during the first 6 months of  a chronic psychotic illness would be changed
to schizophrenia if active ps ychotic or prominent residual symptoms persist over several
years without a recurrence of another mood episode.) 
Comorbidity
Many individuals diagnosed with schizoaffect ive disorder are also diagnosed with other
mental disorders, especially substance use d isorders and anxiety disorders. Similarly, the
incidence of medical conditions is increase d above base rate for the general population
and leads to decre ased life expectancy.
Substance/Medication-Induced
 Psychotic Disorder
Diagnostic Criteria  
A. Presence of one or both of the following symptoms:
1. Delusions.
2. Hallucinations.
B. There is evidence from the history, physical examination, or laboratory findings of both
(1) and (2):
1. The symptoms in Criterion A developed during or soon after substance intoxication
or withdrawal or after exposure to a medication.
2. The involved substance/medication is capable of producing the symptoms in Crite-
rion A.