ABSTRACT
The regulation of the Hypothalamus-Pituitary-Adrenal axis (HPA-axis) with its end product cortisol seems to be affected in several psychiatric disorders. Although findings are not conclusive, internalizing symptoms have primarily been associated with higher diurnal cortisol levels and externalizing symptoms with lower cortisol levels. In this study on nine-year-olds in Nicaragua (n=111), we investigated associations between child psychiatric symptoms, using the Child Behavior Check List (CBCL), and saliva cortisol levels collected in the morning and afternoon, also adjusting for potential confounders. In line with previous findings, internalizing symptoms were significantly associated with higher morning, but not afternoon cortisol levels. Surprisingly, externalizing symptoms were also significantly associated with higher morning cortisol levels. Possibly, this association between externalizing symptoms and cortisol levels may be characteristic of early ages, representing a higher exposure to external stressors. The study highlights the need for prospective studies, following the development of the HPA-axis and its association with psychiatric symptoms.