546 Substance-Related and Addictive Disorders
are not seen in sedative-type withdrawal. Dilated pupils ar e also seen in hallucinogen
intoxication and stimulant in toxication. However, other si gns or symptoms of opioid
withdrawal, such as nausea, vomiting, diarrhea, abdominal cramps, rhinorrhea, or lacri-
mation, are not present. 
Comorbidity 
The most common medical conditions associated with opioid use disorder are viral (e.g.,
HIV, hepatitis C virus) and bact erial infections, particularly among users of opioids by in-
jection. These infections are less common in opioid use disorder with prescription opioids.
Opioid use disorder is often associated with other substance use disord ers, especially those
involving tobacco, alcohol, cannabis, stimulants, and benzodiazepines, which are often
taken to reduce symptoms of op ioid withdrawal or craving for opioids, or to enhance the ef-
fects of administered opioids. Individuals with opioid use disorder are at risk for the devel-
opment of mild to moderate depression that  meets symptomatic and duration criteria for
persistent depressive disorder (dysthymia) or, in some cases, for major depressive disorder.
These symptoms may represent an opioid-induc ed depressive disorder  or an exacerbation
of a preexisting primary depres sive disorder. Periods of depression are especially common
during chronic intoxication or in association with physical or psychosocial stressors that are
related to the opioid use disorder. Insomnia is common, especially during withdrawal. An-
tisocial personality disorder is much more common in individuals with opioid use disorder
than in the general population. Posttraumatic stress disorder is also seen with increased fre-
quency. A history of conduct disorder in childh ood or adolescence has been identified as a