Autonomic reactivity and psychopathology in middle childhood.

BACKGROUND Better indicators are needed for identifying children with early signs of developmental psychopathology. AIMS To identify measures of autonomic nervous system reactivity that discriminate children with internalising and externalising behavioural symptoms. METHOD A cross-sectional study of 122 children aged 6--7 years examined sympathetic and parasympathetic reactivity to standardised field-laboratory stressors as predictors of parent- and teacher-reported mental health symptoms. RESULTS Measures of autonomic reactivity discriminated between children with internalising behaviour problems, externalising behaviour problems and neither. Internalisers showed high reactivity relative to low-symptom children, principally in the parasympathetic branch, while externalisers showed low reactivity, in both autonomic branches. CONCLUSIONS School-age children with mental health symptoms showed a pattern of autonomic dimorphism in their reactivity to standardised challenges. This observation may be of use in early identification of children with presyndromal psychopathology.