- OBJECTIVE: This study examined the prevalence of, and association between, childhood abuse and psychiatric disorders in single and married mothers. METHOD: Single and married mothers who participated in the Ontario Health Survey, a province-wide study derived from a probability sample of the general population of Ontario aged 15 years and older (N=1,471), were included. Sociodemographic and mental health characteristics were collected by means of interviewer-administered questionnaires. A self-administered questionnaire was used to collect information on childhood physical and sexual abuse. RESULTS: Compared with married mothers, single mothers reported substantially lower incomes as well as higher rates of childhood abuse and all psychiatric morbidities examined (current and lifetime affective or anxiety disorders and substance use disorders). Childhood abuse had a consistent and significant association with adult mental health, even when other risk variables were controlled. No interaction among childhood abuse and marital status and outcome was found. CONCLUSIONS: Single mothers reported more childhood abuse and experienced higher levels of poverty and psychiatric disorders than married mothers. Childhood abuse was associated with more psychiatric problems in both single and married mothers. Research, clinical, and policy implications of these findings are discussed.