['Stressful life events are associated with mood disorders in adults in clinical settings. Less described in the literature is the association between common life stressors and a wide range of psychopathology in young adolescents. This study uses a large non-clinical sample of young adolescents to describe the associations among worry or stress about common life events/difficulties, mental health and substance use.', 'Data on lifetime stress or worry about common life events/difficulties (i.e., romantic breakups, family disruption, interpersonal difficulties, and personal stress (health, weight, school work)), symptoms of depression, conduct disorder symptoms, and substance use were collected from 1025 grade 7 students (mean age 12.9 years; 45% male). The association between each source of stress and each mental health and substance use indicator was modeled in separate logistic regression analyses.', 'The proportion of adolescents reporting worry or stress ranged from 7% for new family to 53% for schoolwork. Romantic breakup stress was statistically significantly associated with all the mental health and substance use indicators except illicit drug use. Family disruption was statistically significantly associated with depression symptoms, marijuana use, and cigarette use. Interpersonal difficulties stress was statistically significantly associated with depression symptoms. All sources of personal stress were statistically significantly related to depression symptoms. In addition, health-related stress was inversely related to binge drinking.'] Are common stressful life events and difficulties associated with mental health symptoms and substance use in young adolescents?