Cognitive mechanisms linking low trait positive affect to depressive symptoms: a prospective diary study.

Low trait positive affect represents an affective vulnerability to depression, but little research has examined mechanisms linking low trait positive affect to depressive symptoms. The current study investigated whether the cognitive strategies of dampening and positive rumination mediated the prospective association between low trait positive affect and depressive symptoms. Participants were 209 undergraduate students who participated in an eight-week online study. Depressive symptoms and trait temperament were assessed at baseline, followed by seven weekly questionnaires which assessed cognitive strategies in response to weekly events and weekly depressive symptoms. Data were analysed using multilevel modelling following the mediation approach proposed by Nezlek. Results indicated that low trait positive affect significantly predicted less positive rumination but not greater dampening in response to weekly positive events. Less positive rumination in response to weekly positive events partially mediated the association between low trait positive affect and greater depressive symptoms across the study.