The Effect of Everyday Stressors and the Perceived Stress Reactivity Scale on Variability in Sympathetic Arousal

This ecological momentary assessment study examined the effect of naturally occurring stressors and perceived stress reactivity on alpha-amylase, a proxy of sympathetic nervous system arousal. There are age-related changes in physiological systems sensitive to stress, so the sample included 174 adults ages 20-78 (M=48.65, SD=19.28). At the beginning of the study, participants completed the Perceived Stress Reactivity Scale (PSRS; Schulz et al., 2005). For 10 consecutive days, participants were prompted five times per day to report exposure to stressors. During the same 10-day period, participants provided seven saliva samples per day, assayed for alpha-amylase. Multilevel modeling was used to examine daily and momentary associations between stressors, the PSRS, and alpha-amylase activity. On a daily basis, stressors did not predict changes in the diurnal alpha-amylase pattern, but higher perceived stress reactivity predicted steeper diurnal slopes and lower total daily output. A significant cross-level interaction emerged showing people higher in perceived stress reactivity had steeper awakening responses on days they experienced more stressors than usual. On a momentary basis, alpha-amylase levels were higher on occasions when participants reported stressors. In addition, higher levels of perceived stress reactivity predicted lower overall alpha-amylase levels. Findings suggest that 1) stressors are associated with elevations in momentary but not daily aggregate levels of alpha-amylase, and 2) the PSRS has prospective validity as a predictor of stress-related fluctuations in diurnal alpha-amylase patterns. Age was not a significant moderator of the relationship between stressors and alpha-amylase, potentially suggesting the effect of stressors on alpha-amylase activity is age invariant.