nabis use and cannabis use disorder are highly comorbid with other substance use disor-
ders. Co-occurring mental co nditions are common in canna bis use disorder. Cannabis use
has been associated with poor er life satisfaction; increased mental health treatment and
hospitalization; and higher rates of depressi on, anxiety disorders, suicide attempts, and
conduct disorder. Individuals with past-year or lifetime cannabis use disorder have high
rates of alcohol use disorder (greater than 50%) and tobacco use disorder (53%). Rates of
other substance use disorders are also likely to be high among individuals with cannabis
use disorder. Among those seeking treatmen t for a cannabis use disorder, 74% report
problematic use of a secondary or tertiary su bstance: alcohol (40%), cocaine (12%), meth-
amphetamine (6%), and heroin or other opia tes (2%). Among those younger than 18 years,
61% reported problematic use of a secondary su bstance: alcohol (48%), cocaine (4%), meth-
amphetamine (2%), and heroin or other opiates (2%). Cannabis use disorder is also often
observed as a secondary problem among those with a primary diagnosis of other substance
use disorders, with approximately 25%–80% of those in treatment for another substance
use disorder reporting use of cannabis.
Individuals with past-year or lifetime diag noses of cannabis use disorder also have
high rates of concurrent ment al disorders other than substa nce use disorders. Major de-
pressive disorder (11%), any anxiety disorder (24%), and bipolar I disorder (13%) are quite
common among individuals with a past-year di agnosis of a cannabis use disorder, as are
antisocial (30%), obsessive-co mpulsive, (19%), and paranoid (18%) personality disorders.
Approximately 33% of adolescents with canna bis use disorder have internalizing disor-