Risk factors for childhood mental health symptoms: national longitudinal study of Australian children.

OBJECTIVE

To determine predictors of child externalizing (behavioral) and internalizing (emotional) symptoms in a national population sample.

METHODS

Data were collected in 3 biennial waves (2004, 2006, and 2008) from 2 cohorts in the Longitudinal Study of Australian Children, initially including 5107 children 0 to 1 year of age and 4983 children 4 to 5 years of age. The primary outcomes were child externalizing and internalizing symptoms. Relationships between potential risk factors and child mental health outcomes were described by using linear regression.

RESULTS

In unadjusted analyses, children's mental health symptoms were predicted by a large number of risk factors. In multivariate models, early childhood factors (birth through 5 years) explained 30% and 18% of variations in externalizing and internalizing symptoms, respectively, at 4 to 5 years of age. Middle childhood (5-9 years of age) factors explained 20% and 23% of variations in externalizing and internalizing symptoms, respectively, at 8 to 9 years of age. Harsh discipline was a strong consistent predictor of externalizing symptoms in both age groups, whereas poorer child physical health, maternal emotional distress, harsh discipline, and overinvolved/protective parenting (younger cohort only) predicted internalizing symptoms consistently.

CONCLUSIONS

National data on predictors of child mental health symptoms highlighted a small number of significant risk factors, situated in the family context and present from a very young age. This knowledge is informing population-level, randomized, prevention trials of family support programs.