Beliefs about possessions associated with Hoarding Disorder: A systematic review and meta-analysis

There is substantial evidence highlighting the importance of beliefs about possessions in understanding and treating Hoarding Disorder. Despite this, there has not yet been a comprehensive review of this topic. The aim of the current pre-registered systematic review and meta-analysis was to synthesise the evidence base concerning the association between hoarding beliefs and hoarding symptom severity. Meta-analytic techniques were used to pool effect sizes concerning the association between hoarding beliefs and symptom severity (r, d) and narrative synthesis was applied to data which could not be included in the meta-analysis. 30 studies were eligible for inclusion in the review, with 24 studies contributing data for meta-analyses. Meta-analysis results indicated a small-medium significant association between beliefs about possessions and hoarding severity. This was generally consistent when considering specific belief types (i.e., emotional attachment, responsibility, memory, control) and specific hoarding symptoms (i.e., acquiring, difficulty discarding, clutter). Narrative synthesis confirmed that a range of beliefs about possessions were associated with hoarding symptoms amongst those with clinically significant hoarding symptoms. Results also suggested that, compared to other psychological constructs (e.g., emotional dysregulation), beliefs about possessions generally had more consistent and stronger associations with hoarding severity, or acted as mediators for constructs that had a large association with hoarding severity. Overall, the results provide support for the importance of beliefs about possessions in the future research and treatment of Hoarding Disorder.