Depressive mood state appears to mediate the association between gratitude and self-reported sleep quality metrics. We suggest, as one plausible model of these phenomena, that highly grateful individuals have lower symptoms of depression, which in turn leads to fewer presleep worries, resulting in better perceived sleep quality. Future work should aim to disentangle the causal nature of these relationships in order to better understand how these important variables interact.

High levels of trait gratitude are associated with lower levels of depressive symptoms, but the potential mechanisms underlying this relationship have not been extensively studied. One potential explanation for this relationship is that individuals with higher levels of trait gratitude may have a more positive cognitive style, such that they interpret, attend to, and remember events in a more positive rather than negative manner. This study aimed to explore whether one aspect of a positive cognitive style, a positive interpretation bias, is a mediator in the relationship between trait gratitude and depressive symptoms. During a single visit to the lab, we asked eighty-eight individuals (41 females) to complete a measure of trait gratitude (the Gratitude Resentment and Appreciation Test [GRAT]), two measures of interpretation bias (the Sentence Completion Test for Depression [SCD], and the Ambiguous Scenarios Test for Depression [ASTD]), and a measure of depressive symptoms (the Beck Depression Inventory [BDI-II]). The results of the mediation analyses indicated that a positive interpretation bias partially explained the relationship between trait gratitude and depressive symptoms. These findings suggest that trait gratitude may reduce depressive symptoms in part through its effects on positive thinking patterns. Future longitudinal studies will be needed to elucidate the causal relationship between these variables in greater detail. Keywords Gratitude . Cognitive bias . DepressionThe experience of gratitude is familiar to all of us; yet, relative to other constructs (e.g., hope, optimism) it has received less attention in positive psychology research to date (Wood et al. 2010). It has also been a more difficult construct to define consistently