Clinical features and treatment characteristics of compulsive hoarding in Japanese patients with obsessive-compulsive disorder.

INTRODUCTION: Compulsive hoarding has been studied primarily in Western countries. Here we sought to examine compulsive hoarding in Japanese patients with obsessive-compulsive disorder (OCD). The heterogeneous nature of hoarding was also investigated.
METHODS: One hundred and sixty-eight OCD outpatients were initially assessed to determine the presence or absence of compulsive hoarding, and whether hoarding was primary or secondary to another symptom dimension for which they had received treatment for 1 year.
RESULTS: Of the participants, 54 patients were found to have compulsive hoarding. Hoarders were significantly more likely than non-hoarding patients to have more severe psychopathology including elevated severity of OCD symptoms, poorer insight, higher prevalence of comorbid schizotypal or obsessive-compulsive personality disorder, closer association with symmetry dimension, and poorer treatment outcome. Comparisons of subjects with primary and secondary hoarding found that the former group had more severe clinical features, while the latter group hoarded a wider variety of items, including apparently bizarre ones.
CONCLUSION: The prevalence and clinical characteristics of compulsive hoarding in OCD subjects was similar to those reported in Western countries, supporting its trans-cultural consistency. The distinction between primary and secondary hoarding in OCD is clinically useful, and may contribute to the debate about whether hoarding should be a separate diagnostic entity.