nitive impairment, inability to concentrate, and fatigue. 
Prominent and severe sleep disturbances can occur in association with intoxication
with the following classes of substances: alco hol; caffeine; cannabis; opioids; sedatives,
hypnotics, or anxiolytics; st imulants (including cocaine); and other (or unknown) sub-
stances. Prominent and severe sleep disturbances can occur in association with withdrawal