ICD-116B24	HOARDING DISORDER Hoarding disorder
ICD-10F63.8	Other habit and impulse disorders
DSM-5-TRF42.3	Hoarding Disorder

1. Definition and nosology

Hoarding disorder (ICD-11: 6B24; DSM-5-TR: F42.3 Hoarding Disorder) — a persistent need to acquire or save possessions and persistent difficulty discarding them, leading to clutter of living spaces (to the extent that rooms cannot be used for their intended purpose). Categorized under the OCD spectrum.

2. History

• Frost R.O., Hartl T.L. (1996) — cognitive-behavioral model of hoarding.
• DSM-IV — Was noted as a subtype of OCD.
• DSM-5 (2013) and ICD-11 — formally established as a distinct diagnostic category (evidence base — distinct clinical manifestations, course, treatment response).

3. Epidemiology

• Lifetime prevalence: 2–6% (Samuels J.F. et al. Behav Res Ther 2008).
• In older adults, prevalence is higher (~6%).
• Gender: approximately equal; women predominate in clinical samples.
• Onset: adolescence (mean 11–15 years); severity increases with age.
• Comorbidity: MDD ~50%, OCD ~20%, GAD, social anxiety, ADHD.

4. Aetiology and pathogenesis

• Heritability 50%.
• Neurobiological — frontostriatal circuit disruption; activation patterns distinct from OCD (Tolin D.F. et al. reviews).
• Cognitive deficits — categorization, decision-making, attention (Frost & Hartl model).
• Emotional attachment to objects; loss trauma.
• In older adults — trigger for cognitive decline.

5. Clinical features

• Persistent difficulty acquiring objects (purchasing, obtaining free, gift) or storing them.
• The thought of discarding or releasing objects causes significant distress.
• Hoarding items and occupying the living space — rooms cannot be used for their intended functional purposes (the bedroom for sleeping, the kitchen for eating, etc.).
• Sometimes “animal hoarding” — the mass keeping of animals.
• Insight often poor — patient does not accept the problem.
• Health and safety risks — fire, infections, falls, social isolation, eviction.

6. Diagnosis

6.1 Unified diagnostic criteria

A. Persistent difficulty discarding or parting with acquired items, regardless of value.

B. This difficulty arises from a persistent need to keep items and distress associated with discarding.

C. Hoarding clogs the living area and significantly disrupts purposeful use of rooms.

D. Significant distress or functional impairment (including dangerous environment to self, family, others).

E. Excluding medical conditions (brain injury, dementia).

F. Not better explained by another mental disorder (OCD ‘obsessions’, MDD ‘lack of energy’, psychotic disorder delusions, autism ‘restricted interests’).

Qualifier: with excessive acquisition; insight (good / moderate — poor / absent).

6.2 Source-specific clarifications

• DSM-5-TR / ICD-11 — separate category; insight qualifier.
• “Animal hoarding” — although not a separate specifier, it is a clinically recognized variant; collaboration with veterinary and public health authorities is required.

6.3 Diagnostic algorithm

1. Clinical interview.
2. Home visit or photographic evidence — condition of living space (Clutter Image Rating).
3. Scale - Saving Inventory-Revised (SI-R).
4. Comorbidity and cognitive assessment (dementia exclusion in elderly — MMSE/MoCA).
5. Safety and health risk assessment.

6.4 Differential diagnosis

7. Examination and assessment

• SI-R (Saving Inventory-Revised), CIR (Clutter Image Rating).
• Medical and cognitive examination (MMSE/MoCA for elderly).
• Safety assessment.

8. Treatment

1. CBT for hoarding (Frost R.O., Tolin D.F., Steketee G.) — first-line; manualized 26-session protocol — motivation enhancement, cognitive restructuring, decision-making training, sorting and discarding exercises, home visits. Evidence: Tolin D.F. et al. Depress Anxiety 2015 RCT — medium-large effect.
2. SSRIs — evidence base is limited; SSRIs effective in OCD give a weaker response in hoarding. Adjunctive role.
3. Cognitive remediation — attention, categorization, decision-making training.
4. Buoyancy approach — supporting the patient's internal motivation; risk of re-cluttering after a forced clear-out.
5. Community intervention — public health, social service, fire safety.
6. In older adults — dementia screening and comorbid intervention.

Source-specific specifications

• Tolin D.F. et al. RCTs — CBT is effective; SSRIs limited.
• Saxena S. reviews — response to SSRIs is weaker than that observed in OCD.

Treatment methods

1. CBT for hoarding disorder (Hoarding) — Steketee (Steketee G.), Frost (Frost R.O.) — Manualized 26 sessions — motivational interview, decision-making training, sorting exercise, home visits, cognitive restructuring. IOCDF.
2. Saving Inventory-Revised (SI-R) — Frost (Frost R.O.) — 23 items; three subscales (acquisition, difficulty discarding, clutter).
3. Clutter Image Rating (CIR) — 9-point scale; photo-based assessment of room clutter level.
4. Group CBT — Cost-effective format; long-term support.

9. Prognosis

• Chronic course, severity increases with age.
• Significant improvement with CBT, but full remission rare.
• Comorbid dementia indicates a poor prognosis.

10. Myths and misconceptions

Myth 1: “Hoarding is just a ‘collector’ personality trait or laziness”

Evidence: Hoarding is a clinical disorder — Frost & Hartl cognitive-behavioral model; distinct neurobiology model; functional impairment and health risk. Unlike collectionism, items are not systematized and congest the living area.

Myth 2: “Forcibly cleaning the patient's home ends the problem”

Evidence: A forced clear-out without the patient's consent leads to severe distress, trauma, and re-cluttering within 12 months. Gradual sorting involving patient participation is recommended.

Myth 3: “Hoarding is a subtype of typical OCD; SSRIs are sufficient”

Evidence: DSM-5 and ICD-11 — separate category; response to SSRIs is poor compared to OCD; CBT manualized protocol is first-line.

Myth 4: “Keeping many animals ‘with good intentions’ is good for the animals”

Evidence: “Animal hoarding” — results in animals receiving poor hygiene, food, and medical care; high animal mortality, survivors in severe condition; requires intervention from veterinary and public health authorities.

Myth 5: “Hoarding in the elderly is ‘normal aging’”

Evidence: In elderly individuals, this may be a marker for frontotemporal dementia in particular; cognitive assessment is required.

Myth 6: “Once cleaned, the problem is solved”

Evidence: Hoarding is a chronic disorder; long-term treatment and community support are required.

11. Sources

1. WHO. ICD-11. 6B24 Hoarding disorder. 2024.
2. APA. DSM-5-TR. 2022.
3. Frost R.O., Hartl T.L. A cognitive-behavioral model of compulsive hoarding. Behav Res Ther 1996;34(4):341–350.
4. Steketee G., Frost R.O. Treatment for Hoarding Disorder: Therapist Guide. Oxford Univ Press; 2014.
5. Tolin D.F., Frost R.O., Steketee G. et al. Cognitive behavioral therapy for hoarding disorder: a meta-analysis. Depress Anxiety 2015;32(3):158–166.
6. Samuels J.F. et al. Prevalence and correlates of hoarding behavior in a community-based sample. Behav Res Ther 2008;46(7):836–844.
7. Saxena S. Pharmacotherapy of compulsive hoarding. J Clin Psychol 2011;67(5):477–484.