The relationship between work-related rumination and evening and morning salivary cortisol secretion.

The perseverative cognition hypothesis suggests that worry/ruminative thinking prolongs stress-related physiological activation. This study explored the association of work-related rumination with salivary cortisol sampled at 10 pm and the cortisol awakening response (CAR) the following morning. On a mid-week evening, 108 school teachers completed a small diary about their work-related thoughts and gave a saliva cortisol sample at 10 pm. The following morning, they gave four additional saliva samples: at awakening and at 15, 30 and 45 min after awakening, along with a rating of their anticipatory thoughts about work. The CAR was calculated as the percentage increase in cortisol secretion from awakening to 30 min, and the sample was divided at their respective medians to classify participants into low and high rumination groups. Cortisol secretion was found to be significantly greater in the high compared with the low ruminators at 10 pm, and this effect was not related to leisure activities or work patterns during the evening. For the morning measures, high ruminators demonstrated a flattened CAR relative to the low ruminators, and this effect appeared to be associated with sleep disturbance during the night. Ruminating about work-related issues is associated with cortisol secretion, and our findings support the perseverative cognition hypothesis.