Decluttering Minds: Psychological interventions for hoarding disorder - A systematic review and meta-analysis

Background: Cognitive Behavioural Therapy (CBT) is conventionally considered the primary intervention for Hoarding Disorder (HD), yet various psychological interventions have recently emerged. This study, pre-registered at Prospero (CRD42023427534), aims to comprehensively assess a range of psychological interventions, including CBT, for reducing HD symptomatology.

Methods: A systematic literature search using PubMed and SCOPUS identified 41 eligible studies comprising 47 samples (N = 1343). Risk of bias for RCTs was assessed using the Cochrane RoB2 tool, and methodological quality for all studies was evaluated using the Psychotherapy Outcome Study Methodology Rating Form (POMRF).

Results: Pre-post effects revealed a large reduction in HD symptomatology (g = -1.09), sustained at follow-up in 18 studies (g = -1.12, N = 588). Additionally, 8 Randomized Controlled Trials (RCTs) demonstrated a substantial end-of-trial reduction in HD symptoms compared to controls (g = -0.75). Meta-regression found no moderating effects for: demographics, medication use, number of treatment sessions, or study quality. Similarly, no differences were observed between group and individual therapy, therapy with or without home visits, or CBT versus other psychological interventions.

Conclusion: This study confirms psychological therapies are effective in reducing hoarding symptoms, while indicating no superiority for CBT. Despite the benefits, symptoms often persist above the clinical cut-off for HD, highlighting the enduring clinical challenges in achieving symptomatic remission. The findings underscore the need to address methodological limitations and possible age and gender bias in future research to enhance the efficacy and inclusivity of psychological interventions for HD.