A MEASUREMENT MODEL OF CORTISOL REACTIVITY OF HEALTHY OLDER ADULTS

Research on the physiological adaptation process has found that stress is associated with the rate of cortisol secretion, the main hormone t hat reflects stress. However, considerable variation among subjects ha s been reported. Using a sample of older adults (N = 46), we tested th e hypothesis that cortisol reactivity is composed of (1) a situation-r elated component representing hypothalamic influence on cortisol secre tion observed on three different occasions, and (2) a stable component representing a general trait responsible for cortisol responses obser ved from occasion to occasion. LISREL VIII was used to test this hypot hesis. Results indicated that a homogeneous reliability model was not supported by the data. A congeneric measurement model represented a be tter fit to the data. Results suggest that subjects have consistent pa tterns of response during separate experimental occasions. However, re sults do not suggest a consistent pattern of response over lime. The m ain implication of these results is that salivary cortisol measures ar e sensitive to experimental stress situations. As such, this noninvasi ve method may be useful in examining adaptive responses to stress.