UCLA

Chronic exposure to high levels of stress in childhood pose risk for mental health problems. However, the effects of mild daily stress on youth psychological functioning is poorly understood. The three studies in this dissertation utilize intensive repeated data (e.g., daily diaries) to examine how children react to and recover from minor negative events on the same day or the next day. The first study examined children’s emotion reactivity to and recovery from school problems, and assessed their cross-sectional associations with internalizing and externalizing problems in 83 5th and 6th graders. Study used repeated ratings of school problems and positive and negative emotion completed several times a day over five consecutive weekdays. Youths reported more negative emotion and less positive emotion at school and at bedtime on days when they experienced more problems at school. Youths who tended to report more negative emotion on stressful days at school had more symptoms of depression, even after controlling for average levels of exposure to school problems. Youths who tended to recover by bedtime had fewer internalizing problems. The second study examined same day and next day mood responses to school problems over the course of 40 consecutive weekdays in a sample of 47 8-13-year-old youths. On average, youths reported more negative mood and less positive mood on days that they experienced more school problems. School problems were not linked to mood on the next day. Children who tended to report more negative mood or less positive mood on days when they experienced more school problems showed more internalizing problems three years later when they were 11-17 years old. The third study used data from the same sample of 47 children to test the within-and between-person effects of daily negative events – peer problems, academic problems and interparental conflict – on diurnal cortisol, a physiological indicator of stress reactivity. Three indices of diurnal cortisol were derived from saliva samples collected four times a day across eight days: same day diurnal cortisol slope, same day bedtime cortisol, and cortisol at wakeup the next morning. On average, children who reported more peer problems showed flatter slopes of cortisol decline from wakeup to bedtime. However, children secreted more cortisol at wakeup following days when they reported more peer or academic problems than usual. Interparental conflict was not significantly associated with diurnal cortisol. In sum, this dissertation showcases a novel application of intensive repeated methods in developmental psychopathology research. Using this methodology, studies found individual differences in reactivity to and recovery from daily problems, which in turn were associated with youth internalizing problems.