Working memory impairment in cannabis- and opioid-dependent adolescents.

Background: Cannabis and opioid use are associated with cognitive impairment, whether preexisting or substance-induced, but there have been few substance-specific assessments of cognitive functioning in adolescent substance users. Working memory impairment may be particularly important, as it has been linked to poorer performance in substance abuse treatment.

Methods: Working memory (Wechsler Intelligence Scale for Children-IV or Adult Intelligence Scale-IV) and baseline substance use were assessed in 42 youth (mean age = 17.