these studies have largely relied on the retrospective reports of adults about maltreatment and substance use in childhood and adolescence,3,7,8 which decrease in accuracy with increasing age.20-22 Third, most studies have assessed clinical or convenience samples,7,8,13 limiting the potential to provide population estimates for the efficacy of any interventions or policy changes, and precluding conclusions of whether these associations would persist among more diverse samples. Fourth, no prior studies that we are aware of have examined effects across specific types of illicit drugs that could help in understanding the etiology of drug use problems and in targeting interventions to prevent adolescent drug use.23,24 Fifth, no studies have examined whether associations between PTEs and adolescent drug use are equivalent for individuals with or without comorbid psychiatric disorders, even though there is robust evidence of multifinality following exposure to PTEs,25-27 particularly for posttraumatic stress disorder (PTSD) and substance use.28-30 Finally, prior studies have not controlled for the potential confounding or moderating effects of parental substance misuse in estimates of substance use outcomes,9,13 or have treated parental substance misuse as a direct form of adversity.3,7,10 Parental substance misuse could confound the association between childhood PTEs and adolescent drug use because of its association
