Hoarding as a Behavioral Addiction

Overview

Hoarding disorder (HD) is defined as the acquisition of—and inability to discard—a large number of possessions, to a degree that precludes intended use of living spaces and creates significant distress or impairment in functioning. Hoarding can interfere with an individual’s ability to work, interact with others, and perform basic activities, such as eating or sleeping. In severe cases, it may lead to dangerous, even life-threatening living conditions. Hoarding also is associated with a profound public health burden. In a survey of local health departments, 64% of health officers reported receiving hoarding complaints, some of which resulted in a significant cost to the community. A large Internet survey of self-identified hoarding participants (N = 864) and family members (N = 655) revealed that compulsive hoarding is related to poor physical health, social service involvement, and significant occupational impairment.

Hoarding has been linked previously to anxiety disorders, specifically obsessive-compulsive disorder (OCD); however, it is now defined in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) as a discrete disorder. Consistent with prominent models of anxiety disorders, individuals who hoard frequently report feelings of anxiety when they are asked to discard or organize their possessions. They also may demonstrate avoidance and safety behaviors connected to their hoarding-related beliefs and fears. There is, however, a pleasurable or gratifying component associated with acquiring, collecting, and saving possessions that distinguishes hoarding from other anxiety-related problems.

This appetitive aspect of hoarding suggests that there are similarities between hoarding and behavioral addictions, which include several impulse control disorders (pathological gambling, pyromania, and kleptomania). In behavioral addictions, individuals experience pleasurable or gratifying feelings while engaging in the target behavior, followed by a decrease in arousal and feelings of guilt and remorse. An individual who compulsively collects items from yard sales and thrift stores may similarly feel a rush of positive emotion upon finding an item that she feels is unique or valuable, followed by feelings of regret when she reflects upon how much the clutter is overtaking her home and negatively impacting her life. Although the anxiety-related aspects of hoarding have been the subject of several investigations, the appetitive nature of this syndrome has been relatively understudied. Hoarding behavior is sometimes motivated by a desire to reduce anxiety; however, there are cases in which hoarding appears to be driven by anticipation of pleasure and impaired self-regulation. There also may be cases in which both avoidance and approach behaviors play a role. From a clinical perspective, this underscores the importance of functional analysis in determining motivation for hoarding and, more specifically, acquisition behaviors.

Classification and Comorbidity

Hoarding was long considered a dimension or subtype of OCD. Findings of moderate frequencies of hoarding behavior in OCD populations, ranging from 18% to 33%, supported this association. Moreover, several studies found that individuals who hoard report more OCD symptoms than nonhoarding individuals do. Frost and colleagues compared individuals with OCD who hoarded versus those who did not, and found that the two groups did not differ on the number of OCD symptoms displayed, although they both reported more OCD symptoms than did anxious and nonclinical control participants.

Despite this association, mounting evidence began to suggest that hoarding was distinct from other OCD symptom dimensions. Most factor analyses of OCD symptoms found that hoarding constituted a separate factor from other obsessions and compulsions. Furthermore, hoarding behavior has been reported in a variety of psychiatric disorders besides OCD, including schizophrenia, organic mental disorders, eating disorders, brain injury, and dementia. Finally, hoarding is typically a poor predictor of treatment outcome in both psychological and pharmacological treatments for OCD, although several recent studies have not confirmed this association. In light of the conflicting evidence regarding the diagnostic status of hoarding, Wu and Watson examined the relationship between OCD and hoarding in two large samples. They found that hoarding correlated only modestly with other OCD symptoms, which reliably correlated with each other. Furthermore, hoarding was not more strongly associated with OCD symptoms than other dimensions of psychopathology, such as depression. Subsequently, large epidemiological studies have demonstrated that hoarding difficulties are more prevalent than first thought, and are not definitively associated with one particular disorder. Together, this research led to the development of criteria for hoarding disorder, which were included in the DSM-5.

It is notable for the present discussion that not all individuals who hoard have comorbid symptoms reflective of typical OCD. In addition, hoarding beliefs and behaviors do not always fit the OCD model. Steketee and Frost noted that hoarding thoughts may not always impel the associated compulsive behaviors, may not be as intrusive as typical obsessions, and are not always viewed as ego-dystonic by the individual. In addition, many individuals who hoard lack insight into the severity of the consequences of their behaviors and can experience attenuated levels of distress compared with OCD clients. The lack of insight and ego-syntonic nature of hoarding is similar to that observed in some addictive and impulse control disorders, suggesting some overlap in phenomenology between hoarding and many behavioral addictions.

Hoarding and Impulse Control Disorders

Most relevant to the current chapter is the association between hoarding and the spectrum of impulse control disorders. Impulse control disorders are positively reinforcing to the individual and are associated with a wide variety of emotional states, including pleasure or gratification. They are characterized by repetitive behaviors and impaired inhibition of these behaviors, and include pathological gambling, skin picking, and trichotillomania. Researchers have suggested that impulse control disorders may best be conceptualized as part of an obsessive compulsive spectrum, as the urges and subsequent behavioral responses observed in impulse control disorders appear, at least superficially, similar to the excessive rituals observed in OCD. Problems removing unwanted thoughts and deficits in decision making may also represent commonalities between OCD and impulse control disorders.

A key difference between impulse control disorders and OCD, however, is that an individual with an impulse control disorder experiences feelings of pleasure and gratification while engaging in the target behavior, in contrast to the anxiety experienced when individuals with OCD engage in a compulsion. For example, the repetitive and often harmful rituals performed in OCD may appear similar to the wagering behaviors of compulsive gamblers. When significant monetary losses fuel chasing behavior, a compulsive gambler may feel compelled to gamble to avoid negative consequences in much the same way that rituals in OCD are performed in an effort to alleviate negative emotional states such as anxiety, shame, and guilt. However, gambling behaviors are clearly pleasurable and reinforcing. Individuals who hoard also derive a sense of pleasure and gratification from their acquisition behaviors, which may suggest that hoarding fits better among the impulse control disorders than its common conceptualization as a subtype of OCD.

Hoarding has been linked to poor impulse control in a variety of studies, suggesting the possibility of a common diathesis underlying both hoarding and certain impulse control disorders. Samuels et al. ⁸³ reported a greater frequency of trichotillomania and skin picking among hoarding compared with nonhoarding individuals with OCD. Rasmussen et al. found that hoarding individuals displayed poor response inhibition on standardized laboratory tasks relative to individuals with anxiety disorders, despite reporting similar levels of impulse control.

Frost et al. found that pathological gamblers reported significantly more hoarding symptoms than light gamblers and speculated that both hoarding individuals and gamblers may share similar concerns about the loss of potential opportunities. Hoarding individuals believe that items may be needed for some future use and, therefore, fear discarding items as this would represent a lost opportunity for the item’s use, with some research suggesting that even the sight of a possession can trigger this fear. Frost and colleagues have suggested that pathological gamblers may have difficulty refraining from purchasing chances because of similar beliefs and fears about losing an opportunity to gain financial benefit. Although Grant et al. found a low prevalence of impulse control disorders overall among individuals with OCD, OCD participants with a lifetime and current impulse control disorder were more likely to report hoarding symptoms. In addition, some research suggests that beliefs about possession and about buying are similar to the beliefs of those with compulsive hoarding. The association between hoarding and impulse control disorders is consistent with McElroy and colleagues’ conceptualization of a compulsive-impulsive spectrum but requires further exploration.

Hoarding and Compulsive Acquisition

Compulsive acquisition is a central component of hoarding, and is of particular significance when considering hoarding as a behavioral addiction. The compulsive acquisition component of hoarding consists, in part, of compulsive buying, which is classified as an impulse control disorder. Compulsive buying has been defined as chronic, repetitive purchasing behavior in response to negative events and or/feelings that is difficult to stop and results in harmful consequences. Similar to other impulse control disorders, compulsive buying is associated with a pattern of tension, pleasure, and subsequent feelings of guilt and remorse. A high level of compulsive buying has been found among individuals who hoard, and, conversely, a high level of hoarding symptoms have been found in compulsive buyers. A study comparing compulsive buyers with noncompulsive buyers found that compulsive buyers scored higher on both OCD and hoarding symptoms, but the relationship between buying and OCD was mainly mediated by hoarding. Of interest, this study found that while not all compulsive buyers suffer from compulsive hoarding, nearly all hoarding participants suffer from compulsive acquisition. Compulsive acquisition in hoarding, however, is not limited to buying, but includes collecting free things that are being given away or that have been discarded by others. However, Frost et al. found that these behaviors were related; a measure of compulsive buying behavior was associated with a compulsive acquisition of free items.

The relationship between hoarding and compulsive buying may be accounted for by shared cognitive deficits and emotional dysregulation. Both hoarding and compulsive buying appear to be closely related to impaired mental control and fears about decision making. In addition, evidence suggests that similar cognitive biases about the meaning of possessions exist in both hoarding individuals and compulsive buyers. Although O’Guinn and Faber suggested that compulsive buyers may derive more emotional pleasure from the process of acquiring items, in contrast to hoarding individuals, who retain a sense of satisfaction from items even once ownership has been established, Kyrios et al. found that compulsive buyers did hold beliefs about possession similar to those reported by hoarding participants. These beliefs included fears over lost opportunities to obtain objects, erroneous beliefs about the inherent value of possessions, and beliefs about personal responsibility for objects. Research on hoarding has suggested that the sight of a possession activates the fear of losing an opportunity.

Compulsive buying and hoarding also share problems with regulating emotions. Individuals who buy compulsively report difficulties accepting and coping with negative emotions, similar to the difficulties in managing emotional distress that hoarding individuals report, both in response to their objects and in day-to-day life. Compulsive buying and hoarding both appear to be driven by negative urgency—a tendency to react impulsively when experiencing negative emotion—which, in hoarding, intensifies emotional attachment to possessions. Compulsive buying and hoarding difficulties are also related to low distress tolerance, in particular a low perceived ability to cope with distress, and the tendency to become absorbed or overwhelmed by the experience of distress. Collectively, these findings suggest a diagnostic overlap between hoarding disorder and impulse control disorders.

Etiology/Biobehavioral Underpinnings of Hoarding

Over the past decade, much new evidence has emerged regarding the biological/neural underpinnings of hoarding. Several case reports have described cases of pathological collecting and saving that began after a brain injury, typically along with other changes in personality and social functioning. These cases suggest that hoarding may be related to frontal lobe dysfunction. Other evidence for the biological correlates of hoarding has come from three domains of research: neuroimaging, electrophysiology, and genetics.