The Maltreatment and Adolescent Pathways (MAP) Longitudinal Project was funded by the Institute of Gender and Health of the Canadian Institutes of Health Research; the Provincial Centre of Excellence for Child and Youth Mental Health at the Children’s Hospital of Eastern Ontario; and the Ontario Ministry of Children and Youth Services. [...] The OSDUS team gratefully acknowledges the participating high school youth and the collaborating boards of education and the support of the Child, Youth and Family Program at the Centre for Addiction and Mental Health, particularly Dr. [...] For teens, alcohol remains the substance of (marijuana) is the most widely used drug among choice; almost half of the students in grade 12 (45.3%) adolescents and is associated with risks similar to those reported alcohol use in the past 30 days, and 30% of alcohol use. [...] The Prevalence of Substance Use among Youth with Maltreatment What is missing from the literature on child maltreatment Histories: in general, and in Canadian samples in particular, is an examination of the rates of substance use among youth Current Findings with histories of maltreatment compared with those Although almost 30% of adolescents in Ontario reported without such histories. [...] The when considering the association between (a) the inclusion of 1.00 within the confidence interval nullifies cumulative substance use score (i.e., the total number the relevance of the relative risk because it suggests of types of substances used), and (b) the type of that the relative risk is equally likely to be non-existent, or maltreatment experienced.