Investigating the mechanisms of hoarding from an experimental perspective.

BACKGROUND Acquiring and discarding objects are routine decision processes for most people. Despite the ubiquitous need to make such decisions, little is known about how they are made and what goes wrong when individuals acquire and fail to discard so many items that many areas of their home become unlivable (i.e., clinical hoarding). We hypothesize that clinical hoarding reflects a normal variation in the tendency to acquire and retain objects, only just at a more extreme level. METHODS To test this hypothesis, we examined 89 nonclinical, undergraduate students' performance on a novel experimental paradigm that measures decisions about acquiring and discarding everyday objects. To test our hypothesis, and validate our task as a possible research tool for studying hoarding, we related decisions on the task to a variety of measures known to correlate with clinical hoarding. The paradigm was sensitive to individual differences, as subjects varied widely in the quantity of objects they chose to acquire and retain under an increasing pressure to discard. In addition, we replicated expected relationships from the clinical hoarding literature between acquisition and retention tendencies and self-report measures of hoarding, indecisiveness, and obsessive-compulsive behavior. RESULTS Our data suggest that decisions about objects, even in a nonclinical undergraduate population, vary widely and are influenced by the same variables that influence clinical hoarding, but to a less extreme degree. CONCLUSIONS Future research with this experimental task can separately investigate the role of acquisition, retention, impulsivity, and sensitivity to constraints in clinical hoarding to inform our understanding of this disorder.