Secondhand smoke exposure and mental health among children and adolescents.

OBJECTIVE: To examine a potential association between biologically confirmed secondhand smoke exposure and symptoms of Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) (DSM-IV) major depressive disorder, generalized anxiety disorder, panic disorder, attention-deficit/hyperactivity disorder, and conduct disorder using a nationally representative sample of US children and adolescents.

DESIGN: Nationally representative cross-sectional survey of the United States.

SETTING: Continental United States.

PARTICIPANTS: Children and adolescents aged 8 to 15 years who participated in the National Health and Nutrition Examination Survey from 2001 to 2004.

INTERVENTION: Measurement of serum cotinine level to assess secondhand smoke exposure among nonsmokers.

MAIN OUTCOME MEASURES: The DSM-IV symptoms were derived from selected modules of the National Institute of Mental Health's Diagnostic Interview Schedule for Children Version IV, a structured diagnostic interview administered by trained lay interviewers.

RESULTS: Among nonsmokers, serum cotinine level was positively associated with symptoms of DSM-IV major depressive disorder, generalized anxiety disorder, attention-deficit/hyperactivity disorder, and conduct disorder after adjusting for survey design, age, sex, race/ethnicity, poverty, migraine, asthma, hay fever, maternal smoking during pregnancy, and allostatic load. Associations with serum cotinine level were more apparent for boys and for participants of non-Hispanic white race/ethnicity.

CONCLUSIONS: Our results are consistent with a growing body of research documenting an association between secondhand smoke exposure and mental health outcomes. Future research is warranted to establish the biological or psychological mechanisms of association.