cutory. On the whole, however, associations  between delusions and particular medical
conditions appear to be less specific  than is the case for hallucinations.
In determining whether the ps ychotic disturbance is attributable to another medical
condition, the presence of a medical condition must be identified and considered to be the
etiology of the psychosis through a physiol ogical mechanism. Although there are no
infallible guidelines for determining whether th e relationship between the psychotic distur-
bance and the medical condition is etiological, several considerations provide some guidance.
One consideration is the presen ce of a temporal association between the onset, exacerba-
tion, or remission of the medical condition an d that of the psychotic disturbance. A second
consideration is the presence of features that  are atypical for a psychotic disorder (e.g.,
atypical age at onset or presence of visual or  olfactory hallucinations). The disturbance must
also be distinguished from a substance/medication-induced psychotic disorder or an-
other mental disorder (e.g.,  an adjustment disorder). 
Associated Features Supporting Diagnosis
The temporal association of th e onset or exacerbation of th e medical condition offers the
greatest diagnostic certainty that the delusions  or hallucinations are attributable to a med-
ical condition. Additional factors may incl ude concomitant treatments for the underlying
medical condition that confer a risk for psychosis independently, such as steroid treatment
for autoimmune disorders.
Prevalence
Prevalence rates for psychotic di sorder due to another medical condition are difficult to es-
timate given the wide variety of underlying medical etiologies. Life time prevalence has