RESUMEN
BACKGROUND: Hoarding is a disorder characterized by excessive acquisition and persistent difficulty in discarding possessions. The behaviour has adverse emotional, physical, social, financial, and legal outcomes for the person with the disorder and family members, and might pose a significant public health problem. Hoarding has been included as a distinct disorder in the Diagnostic and Statistical Manual of Mental Disorders Fifth edition (DSM-5). The prevalence of hoarding disorder is approximately 2-6% globally. The current state of the evidence does not offer clear understanding of the causes of hoarding behaviours. A systematic review of the extant literature was carried out to determine the possible causal factors of hoarding behaviours. METHODS: This review is conducted in line with PRISMA guidelines. The following electronic databases: Medline through Ovid, EMBASE and PsycINFO were searched for relevant articles published between January 2000 and November 2018. Only articles published in English language were included. Two reviewers independently scrutinized the studies and included them in this review. RESULTS: Our search strategy returned a total of 396 references. Preliminary findings suggest that individuals with hoarding behaviours may have a genetic susceptibility; abnormal neural activity in the fronto-temporal, para-hippocampal gyrus and insular parts of the brain has also been identified. Traumatic life experiences have also been posited to predispose individuals to hoard. CONCLUSION: Although the understanding of hoarding disorder hasgrown in recent years, greater efforts are still needed to clarify the etiology and mechanisms of hoarding disorder as these may help in planning of more holistic interventions to treat the problem.