cular disease, and other medi cal disorders may be associated  with a greater likelihood of
psychosis induced by prescription medicati ons as opposed to substances of abuse.
Diagnostic Markers 
With substances for which relevant blood le vels are available (e.g., blood alcohol level,
other quantifiable blood levels su ch as digoxin), the presence of a level consistent with tox-
icity may increase diagnostic certainty.
Functional Consequences of 
Substance/Medication-Indu ced Psychotic Disorder
Substance/medication-induced psychotic diso rder is typically severely disabling and
consequently is observed most frequently in  emergency rooms, as individuals are often
brought to the acute-care setting when it occu rs. However, the disability is typically self-
limited and resolves upon removal of the offending agent.
Differential Diagnosis
Substance intoxication or substance withdrawal. Individuals intoxicated with stimu-
lants, cannabis, the opioid meperidine, or phe ncyclidine, or those withdrawing from alco-
hol or sedatives, may experience altered percep tions that they recognize as drug effects. If
reality testing for these experiences remains inta ct (i.e., the individual recognizes that the
perception is substance induced and neither believe s in nor acts on it), the diagnosis is not
substance/medication-induced psychotic disorder. Instead, substance intoxication or
substance withdrawal, with perceptual disturbances, is diagnosed (e.g., cocaine intoxica-
tion, with perceptual disturba nces). “Flashback” hallucinations that can occur long after
the use of hallucinogens has stopped are diag nosed as hallucinogen persisting perception
disorder. If substance/medication-induced psychotic symptoms oc cur exclusively during
the course of a delirium, as in severe forms of alcohol withdrawal, the psychotic symptoms