the diagnosis.
Substance intoxication or other subs tance/medication-induced disorders. Familiar sub-
stances may be sold in the black market as novel products, and individuals may experience
intoxication from those substances. History, to xicology screens, or chemical testing of the
substance itself may help to identify it.
Different types of other (or unknown) substance–related disorders. Episodes of other
(or unknown) substance intoxication may occur during, but are distinct from, other (or un-
known) substance use disorder, unspecified other (or unknown) substance–related disor-
der, and other (or unknown) substance–induced disorders. 
Other toxic, metabolic, traumatic, neoplastic, vascular, or infectious  disorders that impair
brain function and cognition. Numerous neurological and other medical conditions may
produce rapid onset of signs and symptoms mimi cking those of intoxica tions, including the
examples in Criterion B. Parado xically, drug withdrawals also must be ruled out, because, for
example, lethargy may indicate withdrawal from one drug or intoxication with another drug.
Comorbidity
As with all substance-related disorders, adolescent conduct disorder, adult antisocial per-
sonality disorder, and other subs tance use disorders tend to co-occur with other (or un-
known) substance intoxication.