A taxometric exploration of the latent structure of hoarding.

Despite controversy regarding the classification and diagnostic status of hoarding disorder, there remains a paucity of research on the nosology of hoarding that is likely to inform the classification debate. The present investigation examined the latent structure of hoarding in three, large independent samples. Data for three well-validated measures of hoarding were subjected to taxometric procedures, including MAXimum EIGenvalue, Mean Above Minus Below A Cut, and Latent-Mode factor. Two symptom measures, one of which closely mirrors the proposed diagnostic criteria for hoarding disorder, and a measure of hoarding beliefs were analyzed. Sample 1 (n=2,501) was representative of the general German population, while Samples 2 (n=1,149) and 3 (n=500) consisted of unselected undergraduate students. Findings across all three samples and taxometric procedures provided converging evidence that hoarding is best conceptualized as a dimensional construct, present in varying degrees in all individuals. Results have implications across research and treatment domains, particularly with respect to assessment approaches, treatment response determination, and policy decisions. These findings underscore the need for further investigations on the nosology of hoarding, to help validate this construct as we move forward with respect to our research and treatment efforts, as well as the potential inclusion of hoarding disorder in the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5; American Psychiatric Association, 2012).