116 Schizophrenia Spectrum and Other Psychotic Disorders
severe). (See Clinician-Rated Dimensions of Psychosis Symptom Severity in the chap-
ter “Assessment Measures.”)
Note:  Diagnosis of psychotic disorder due to another medical condition can be made
without using this severity specifier.
Specifiers
In addition to the symptom domain areas identified in the diagnostic criteria, the assess-
ment of cognition, depressio n, and mania symptom domains is vital for making critically
important distinctions between the various schizophrenia spectrum and other psychotic
disorders.
Diagnostic Features
The essential features of psychotic disorder  due to another medical condition are promi-
nent delusions or hallucinations that are judged  to be attributable to the physiological ef-
fects of another medical condition and are not better explained by another mental disorder
(e.g., the symptoms are not a psychologically mediated response to a severe medical con-
dition, in which case a diagnosis of brief psychotic disorder, with ma rked stressor, would
be appropriate). 
Hallucinations can occur in any sensory modalit y (i.e., visual, olfactory, gustatory, tac-
tile, or auditory), but certai n etiological factors are likely to evoke specific hallucinatory
phenomena. Olfactory hallucinations are suggest ive of temporal lobe  epilepsy. Hallucina-
tions may vary from simple and unformed to highly comp lex and organized, depending
on etiological and environmental factors. Ps ychotic disorder due to another medical con-
dition is generally not diagnosed if the individual maintains reality testing for the hallu-
cinations and appreciates that they result from the medical conditio n. Delusions may have
a variety of themes, including somatic, gran diose, religious, and, most commonly, perse-