Daily rumination and diurnal cortisol patterns in Latino adolescents: The moderating role of sex

Latinos make up the fastest-growing ethnic minority group in the United States and are at higher risk for the development of internalizing symptoms in adolescence than other ethnic groups. Rumination has been identified as a transdiagnostic risk factor associated with several internalizing disorders such as depression, anxiety, and comorbidities of the two. Indicators of risk for chronic stress and internalizing disorders can also be observed from the hypothalamic-pituitary-adrenal (HPA) axis (e.g., diurnal cortisol slopes [DCS]; cortisol awakening responses [CAR]). Notably, no studies have examined within-group heterogeneity in the association between rumination and the DCS in Latino populations, and literature on the relation between rumination and the CAR is mixed. Leveraging self-reported rumination and gold-standard salivary cortisol collection procedures, the current study elucidated associations between daily rumination and diurnal cortisol in an adolescent Latino sample (N = 209) and examined sex as a potential moderator of this association. Results indicated a significant, small association between night-before rumination on problems/stress and next-day DCS; on days where participants ruminated more than usual regarding their problems/stress, they experienced, on average, a flatter DCS the following day. Sex differences were detected in the effects of same-day rumination and the CAR, such that greater rumination on feelings was associated with a smaller CAR the same day, but only for males. Findings inform future research regarding potential bidirectional relations of daily rumination and the CAR, as well as how different foci of rumination may have differential associations with physiological stress systems of males and females.