The Determinants of young Adult Social well-being and Health (DASH) study: Association between Total Difficulties Score and health behaviours at age 11–16 years: odds ratio and 95 % confidence interval for smoking, drinking alcohol and skipping breakfast, by gender. Total Difficulties Score derived from the Strengths and Difficulties Questionnaire [19]. Score summed from 20 items assessing conduct problems, hyperactivity, emotional symptoms, and peer problems. Odds ratios derived from logistic multilevel models for smoking and drinking alcohol measured at 11–13 and 14–16 years, and logistic models for skipping breakfast only at 11–13 years. Models adjusted for age, ethnicity, born in the UK or abroad, Family Affluence Scale [24], parental employment, family type, place of worship attendance, religious affiliation, parental care and parental control (measured by the Parental Bonding Instrument [22])