Longitudinal mediators of a randomized prevention program effect on cortisol for youth from parentally bereaved families.

We recently reported that a randomized controlled trial of a family-focused intervention for parentally bereaved youth predicted higher cortisol output 6 years later relative to a control group of bereaved youth (Luecken et al., Psychoneuroendocrinology 35, 785-789, 2010). The current study evaluated longitudinal mediators of the intervention effect on cortisol 6 years later. Parentally bereaved children (N = 139; mean age, 11.4; SD = 2.4; age range = 8-16 years; male; 61% Caucasian, 17% Hispanic, 7% African American, and 15% other ethnicities) were randomly assigned to the 12-week preventive intervention (n = 78) or a self-study control (n = 61) condition. Six years later (mean age, 17.5; SD, 2.4), cortisol was sampled as youth participated in a parent-child conflict interaction task. Using four waves of data across the 6 years, longitudinal mediators of the program impact on cortisol were evaluated. Program-induced increases in positive parenting, decreases in child exposure to negative life events, and lower externalizing symptoms significantly mediated the intervention effect on cortisol 6 years later.