Loneliness & Cortisol in Chinese Undergraduates

The cortisol data were collected from 50 Chinese undergraduate participants across 2 consecutive weekdays. Participants were required to collect 6 samples on each day at (1) waking, (2) 30 min after waking, (3) 3 hr after waking, (4) 6 hr after waking, (5) 12 hr after waking, and (6) bedtime. Psychological data regarding loneliness, daily hassles, and depression were also collected using appropriate instruments. Compliance was monitored using the MEMS TrackCaps (WestRock). Cortisol data across the 2 days were aggregated for the computations of 3 complementary indices of the diurnal cortisol rhythm: AUCG, CAR and diurnal slope (DS). The effects of daily hassles, loneliness and their interactions were examined using multiple regression. The effects of gender, age, waking time, compliance and depression scores were controlled. Results indicate a positive association between loneliness and AUCG or the diurnal output of cortisol, and a significant interaction between daily hassles and loneliness in that higher loneliness is associated with a stronger positive relationship between daily hassles and AUCG. This pattern of findings tends to support the glucocorticoid resistance hypothesis (e.g., Cohen et al., 2012) as well as the differential-stress-buffering hypothesis (Cacioppo et al., 2003).