The profile of executive function in OCD hoarders and hoarding disorder

Abstract

Hoarding disorder is a new mental disorder in DSM-5. It is classified alongside OCD and other presumably related disorders in the Obsessive-Compulsive and Related Disorders chapter. We examined cognitive performance in two distinct groups comprising individuals with both OCD and severe hoarding, and individuals with hoarding disorder without comorbid OCD. Participants completed executive function tasks assessing inhibitory control, cognitive flexibility, spatial planning, probabilistic learning and reversal and decision making. Compared to a matched healthy control group, OCD hoarders showed significantly worse performance on measures of response inhibition, set shifting, spatial planning, probabilistic learning and reversal, with intact decision making. Despite having a strikingly different clinical presentation, individuals with only hoarding disorder did not differ significantly from OCD hoarders on any cognitive measure suggesting the two hoarding groups have a similar pattern of cognitive difficulties. Tests of cognitive flexibility were least similar across the groups, but differences were small and potentially reflected subtle variation in underlying brain pathology together with psychometric limitations. These results highlight both commonalities and potential differences between OCD and hoarding disorder, and together with other lines of evidence, support the inclusion of the new disorder within the new Obsessive-Compulsive and Related Disorders chapter in DSM-5.

Keywords: Cognition; Hoarding; Hoarding disorder; Obsessive compulsive disorder (OCD).

Fig. 1

Performance in OCD hoarders, compulsive hoarders without OCD and controls in the Intradimensional/Extradimensional shift task. Panel (A) shows extradimensional shift (EDS) errors. Panel (B) shows the errors before the EDS stage. Only OCD hoarders had significantly more EDS errors compared to controls and there were no differences in errors before the EDS stage.

Fig. 2

Performance in OCD hoarders, compulsive hoarders without OCD and control participants in the probabilistic learning and reversal task. Panel (A) shows the per cent of participants who passed in each group. Significantly more compulsive hoarders failed in Stage 2 and marginally more OCD hoarders failed compared to controls. Panel (B) shows the per cent of the correct stimulus chosen in the two stages of the task.