A latent State Trait Model of Cortisol in Normally Developing Youth

Research relating salivary cortisol levels with§internalizing and externalizing behavior problems in§youth has yielded inconsistent results, likely due to§the high day-to-day variation in stress regulation.§Understanding stability in this changing system may§require an analytical strategy that separates§variance in cortisol levels attributable to trait- or§"basal" versus state- or "situationally-specific §sources. Early morning saliva samples were obtained§from 654 youth (range 6-16 yrs ) on two successive§days one year apart. Latent state trait modeling§revealed that 70% of the variance in cortisol levels§could be attributed to state-like sources, and 28% to§trait-like sources. Higher levels of externalizing§problems were consistently associated with lower§basal cortisol in boys. This finding is consistent§with studies of at-risk and clinical groups. The§present findings confirm the relationship spans both§normative and atypical child development, and§supports speculations that boys with low cortisol may§be at risk for externalizing behavior problems.