Distorted judgments of the value of possessions are believed to drive excessive acquisition and difficulty discarding in hoarding. Aberrant valuation in hoarding disorder may manifest in an exaggerated endowment effect. We tested this supposition in two studies, using between- (Study 1) and within- (Study 2) subjects designs. We used nonparametric 2×2 ANOVA to contrast the strength of the endowment effect between healthy individuals and those with hoarding disorder. We also used quantile regression analysis to examine the relation between severity of hoarding symptoms and the endowment effect. The data did not reveal an elevated endowment effect among participants with hoarding disorder in either study. However, in both studies self-reported difficulty discarding, the hallmark feature of hoarding, as well as severity of overall hoarding symptoms, positively correlated with between-subject variations in the endowment effect. Symptom improvement following cognitive-behavioral therapy for hoarding did not correspond to a decrease in the endowment effect, potentially indicating a dissociation between hoarding severity and the endowment effect over the course of treatment. Overall, our results suggest the potential value in further study of the endowment effect in hoarding, particularly its trait versus state features and modifiability.Le texte complet de cet article est disponible en PDF.
Keywords : Endowment effect, Compulsive Hoarding Disorder, Difficulty discarding, Individual differences, CBT, Quantile regression analysis