1 Department of Psychology, Concordia University, Montréal, Canada.
2 Center for Clinical Research in Health, Concordia University, Montréal, Canada.
3 Center for Research in Human Development, Concordia University, Montréal, Canada.
4 PERFORM Center, Concordia University, Montréal, Canada.

Sleep is a basic biological process supporting emotion regulation. The emotion regulation function of sleep may be particularly important in the context of chronic stress. To better understand how chronic stress and sleep interact to predict mood, 66 parents of children with autism completed daily diaries assessing parenting stress, negative mood, and sleep quality for 6 consecutive days. Hierarchical linear modelling revealed that daily negative mood was predicted by between-person differences in parenting stress and between-person differences in sleep efficiency. Further, between-person differences in sleep efficiency and within-person differences in sleep satisfaction moderated the impact of stress on mood. These data suggest that sleep disturbances may exacerbate the association between stress and mood in the context of chronic parenting stress. Further, high parenting stress appears to heighten the impact of transient sleep disturbances on mood.