Some individuals with hoarding disorder live in unsanitary conditions that may be a log- ical consequence of severely cluttered spaces and/ or that are related to planning and or- ganizing difficulties. Animal hoarding can be defined as the accumulation of a large number of animals and a failure to provide minimal standards of nutrition, sanitation, and veter- inary care and to act on the deteriorating condition of the animals (including disease, star- vation, or death) and the environment (e.g., severe overcrowding, extremely unsanitary conditions). Animal hoarding may be a special manifestation of hoarding disorder. Most individuals who hoard animals also hoard inanimate objects. The most prominent differ- ences between animal and object hoarding are the extent of unsanitary conditions and the poorer insight in animal hoarding.
Nationally representative prevalence studies of hoarding disorder are not available. Com— munity surveys estimate the point prevalence of clinically significant hoarding in the
United States and Europe to be approximately 2%—6%. Hoarding disorder affects both males and females, but some epidemiological studies have reported a significantly greater prevalence among males. This contrasts with clinical samples, which are predominantly female. Hoarding symptoms appear to be almost three times more prevalent in older adults (ages 55—94 years) compared with younger adults (ages 34—44 years).
Hoarding appears to begin early in life and spans well into the late stages. Hoarding symp- toms may first emerge around ages 11—15 years, start interfering with the individual’s ev- eryday functioning by the mid—ZOs, and cause clinically significant impairment by the mid-30s. Participants in clinical research studies are usually in their 505. Thus, the severity of hoarding increases with each decade of life. Once symptoms begin, the course of hoard- ing is often chronic, with few individuals reporting a waxing and waning course.
Pathological hoarding in children appears to be easily distinguished from develop- mentally adaptive saving and collecting behaviors. Because children and adolescents typically do not control their living environment and discarding behaviors, the possible intervention of third parties (e.g., parents keeping the spaces usable and thus reducing in- terference) should be considered when making the diagnosis.
Temperamental. Indecisiveness is a prominent feature of individuals with hoarding dis- order and their first-degree relatives.
Environmental. Individuals with hoarding disorder often retrospectively report stressful and traumatic life events preceding the onset of the disorder or causing an exacerbation.
Genetic and physiological. Hoarding behavior is familial, with about 50% of individu- als who hoard reporting having a relative who also hoards. Twin studies indicate that ap- proximately 50% of the variability in hoarding behavior is attributable to additive genetic factors.
While most of the research has been done in Western, industrialized countries and urban communities, the available data from non-Westem and developing countries suggest that hoarding is a universal phenomenon with consistent clinical features.
The key features of hoarding disorder (i.e., difficulties discarding, excessive amount of clutter) are generally comparable in males and females, but females tend to display more excessive acquisition, particularly excessive buying, than do males.
Functional Consequences of Hoarding Disorder
Clutter impairs basic activities, such as moving through the house, cooking, cleaning, per- sonal hygiene, and even sleeping. Appliances may be broken, and utilities such as water and electricity may be disconnected, as access for repair work may be difficult. Quality of life is often considerably impaired. In severe cases, hoarding can put individuals at risk for fire, falling (especially elderly individuals), poor sanitation, and other health risks. Hoard- ing disorder is associated with occupational impairment, poor physical health, and high social service utilization. Family relationships are frequently under great strain. Conﬂict with neighbors and local authorities is common, and a substantial proportion of individ- uals with severe hoarding disorder have been involved in legal eviction proceedings, and some have a history of eviction.