Cortisol response to inoculation in 4-year-old children.

This study examined whether there was a cortisol response to inoculation or if pre-inoculation levels were already elevated due to an anticipatory response to going to the doctors' office. For 4-year-old children, a base saliva sample was obtained in the home on a non-stress day, and a pre-inoculation saliva sample was obtained in the doctors' office prior to the stress. Doctors' office pre-inoculation cortisol was higher than home-based cortisol, suggesting the occurrence of an anticipatory cortisol response to the impending stress. Post-inoculation cortisol levels (+20 min) were comparable to home-based cortisol, indicating that there was no cortisol response to the inoculation itself. While there was no mean increase in cortisol, individual differences in cortisol response existed. Cortisol increases were related to important aspects of child behavioral functioning, including internalizing and externalizing behavior ratings.