Adolescent effects on mothers' bedtime cortisol: Cognitive interference as a mediating mechanism

Prior studies have shown that parent and adolescent cortisol are associated across days and that this covariation may be adolescent-driven. This study extends this literature by (a) testing whether parents' cognitive interference (i.e., distracting and ruminative thoughts potentially due to worry) mediates the linkages between adolescent and next-day parent cortisol and (b) whether these linkages were moderated by parent gender or warmth. Daily diary data, including bedtime cortisol, were collected on two samples of employees and their adolescent-aged children (N = 318 dyads, M_{youth age}  = 13.18 years, 74% mothers). We tested mediation with autoregressive cross-lagged models. Moderated mediation by parent gender was found in our bedtime cortisol models. Higher adolescent bedtime cortisol levels were associated with higher next-day levels of mothers' cognitive interference. In turn, higher levels of mothers' cognitive interference were linked to higher mothers' same-day bedtime cortisol levels. These linkages were not significant for fathers. Cognitive interference did not mediate the associations between child and parent area under the curve or cortisol awakening response. No moderation was evident for parental warmth. Results suggest that mothers' cognitions play a key role in the transmission of elevated bedtime cortisol levels from adolescents to their mothers.