This results in severely cluttered living spaces, distress, and impairment in personal, family, social, educational, occupational, or other important areas of functioning.

[7][8] Excessive acquisition is characterized by repetitive urges or behaviours related to amassing or buying property.

[9] It is recognised by the eleventh revision of the International Classification of Diseases (ICD-11)[10][11] and the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5).

[12] Prevalence rates are estimated at 2% to 5% in adults,[13] though the condition typically manifests in childhood with symptoms worsening in advanced age, at which point collected items have grown excessive and family members who would otherwise help to maintain and control the levels of clutter have either died or moved away.

[16] Other factors often associated with hoarding include alcohol dependence and paranoid, schizotypal and avoidant traits.

Frost and G. Steketee, a series of pictures of rooms in various stages of clutter—from completely clutter-free to very severely cluttered.

However, hoarding symptoms typically manifest in early childhood, and worsen to the point of becoming clinically significant during middle age.

In Japan, hoarder houses are known as "garbage mansions" (ごみ屋敷, gomi yashiki), and have become a topic of public alarm in Japanese mass media.

Different reasons have been given for this, such as the effects of family presence earlier in life and limits on hoarding imposed by housing situation and lifestyle.

[30] A second key part of this study was to determine if stressful life events are linked to the onset of hoarding symptoms.

Similar to self-harming, traumatized persons may create a problem for themselves in order to avoid their real anxiety or trauma.

As possessions cannot provide support in the way humans can and because saving excessively can frustrate other people due to its impact on their quality of life, individuals with hoarding disorder may be caught in a feedback loop.

[35] Research on internet-based CBT treatments for the disorder (where participants have access to educational resources, cognitive strategies, and chat groups) has also shown promising results both in terms of short- and long-term recovery.

[39][43] Therefore, it was suggested that future treatment approaches, and pharmacotherapy in particular, be directed to address the underlying mechanisms of cognitive impairments demonstrated by individuals with hoarding symptoms.

Mental health professionals frequently express frustration regarding hoarding cases, mostly due to premature termination and poor response to treatment.

Patients are frequently described as indecisive, procrastinators, recalcitrant, and as having low or no motivation,[39][43] which can explain why many interventions fail to accomplish significant results.

Emily Maguire wrote Love Objects in 2021, a novel about a woman with hoarding disorder that focused on the behavior and the consequences of a hoarder being exposed.

In Nikolai Gogol’s book Dead Souls (1842), wealthy Plyushkin displays hoarding behaviors.

[54] In Charles Dickens's Bleak House (1862), London shop owner Krook hoards items, primarily legal documents.