with various substance use diso rders, and the symptoms of the disorders may be similar
and overlapping. To disentangle symptom pattern s, it is helpful to  inquire about which
symptoms persisted during periods when some  of the substances were not being used.
Other (or unknown) substance/medication-induced disorder. This diagnosis should
be differentiated from instances when the indi vidual’s symptoms meet full criteria for one
of the following disorders, and that disorder is caused by an other or unknown substance:
delirium, major or mild  neurocognitive disorder, psychoti c disorder, depressive disorder,
anxiety disorder, sexual dysf unction, or sleep disorder.
Other medical conditions. Individuals with substance us e disorders, including other
(or unknown) substance use disorder, may present with symptoms of many medical dis-
orders. These disorders also may occur in the absence of other (or unknown) substance use
disorder. A history of little or no use of ot her or unknown substances helps to exclude
other (or unknown) substance use disord er as the source of these problems.
Comorbidity
Substance use disorders, including other (o r unknown) substance use disorder, are com-
monly comorbid with one another, with adol escent conduct disorder  and adult antisocial
personality disorder, and with suicid al ideation and suicide attempts.