جمع اوری و ساختار چند وجهی تکانشگری: بررسی میان فرهنگی

The proposed hoarding disorder represents a serious psychiatric condition and considerable public health burden. Although tremendous strides have been made in understanding the phenomenology and treatment of this condition, many features regarding the etiology and nosology remain unclear. In particular, the association between impulsivity and hoarding, as well as the differential role of impulsivity versus compulsivity has yet to be fully considered. The current investigation sought to fill this gap in the literature by examining the relationship between hoarding and impulsivity across two independent, cross-cultural investigations. Two separate conceptualizations of the impulsivity construct were considered, including the Barratt Impulsivity Scale and the UPPS Impulsive Behavior Scale. Across Study 1 (US young adult sample; N = 372) and Study 2 (German young adult sample; N = 160) results revealed that hoarding was associated with greater rates of impulsivity, despite controlling for theoretically relevant covariates. More fined-grained analyses revealed a differential relationship with respect to the various facets of impulsivity, such that hoarding was most strongly linked with attentional and motor impulsivity, as well as urgency (i.e., impulsive behaviors in response to negative affect) and lack of perseverance. When considered simultaneously, both impulsivity and non-hoarding OCD symptoms explained unique variance in hoarding. The implications of impulsivity for hoarding are discussed from a classification perspective, as well as from a vulnerability standpoint.

Hoarding Disorder is a serious and impairing psychiatric condition that is defined by considerable and impairing clutter, as well as difficulties with discarding and the acquisition of objects (Frost and Hartl, 1996; Frost et al., 2011). Hoarding symptoms and their repercussions can result in immediate health and safety risks within the home and may develop into a serious liability for the sufferer, their loved ones and the community (Frost et al., 2000). While recent strides have been made in understanding the phenomenology and treatment of hoarding (Pertusa et al., 2010), much remains to be explored with respect to the etiology and nosology of this disorder. Historically, hoarding has been considered a symptom of obsessive–compulsive personality disorder and was most closely linked with obsessive–compulsive disorder (OCD) (American Psychiatric Association, 2000; Mataix-Cols et al., 2010). These associations were based on the suggestion that hoarding shared a number of similar features with OCD including an “obsessional” focus on possessions, the “compulsion” to collect objects, and significant anxiety in response to discarding items (Steketee and Frost, 2003). Phenomenological studies on OCD also supported this perspective by demonstrating that hoarding is often a key symptom feature amongst OCD patients (Rasmussen and Eisen, 1988), and has been consistently identified as one of the hypothesized OCD symptom dimensions (Mataix-Cols et al., 2005). In contrast to the argument outlined above, research over the past ten years has increasingly and consistently called the association between hoarding and OCD into question (Pertusa et al., 2010). The current suggestion within the field is that hoarding should be considered a separate disorder (Mataix-Cols et al., 2010; Pertusa et al., 2008; Rachman et al., 2009; Saxena, 2008). First and foremost, effective psychopharmacological and psychotherapeutic treatments for OCD have had little efficacy for hoarding (Mataix-Cols et al., 2005). Researchers have also found that while a small subset of individuals who hoard are driven to do so by their symptoms of OCD (e.g., contamination, checking), the majority of individuals with primary hoarding cite ego-syntonic reasons for acquiring and saving behaviors, which do not fit the classical conceptualization of OCD (Pertusa et al., 2008). Perhaps one of the most striking findings in support of hoarding as a discrete disorder is the low base rate of comorbid OCD in individuals with primary hoarding disorder (17–33%), which is considerably lower than originally expected and lower than the reported comorbidity with depression, generalized anxiety disorder, and social anxiety disorder (Frost et al., 2011; Pertusa et al., 2010). Interestingly, it has been suggested that hoarding may have some overlap with impulse control disorders (Frost et al., 2011; Steketee and Frost, 2003). Similar to individuals with various addictions or impulse control difficulties, individuals with hoarding report experiencing pleasure or relief upon engaging in acquiring or saving behaviors (Steketee and Tolin, 2011). In particular, excessive acquisition behaviors in hoarding appear to share these characteristics (Frost et al., 2009). Those with hoarding also frequently view their symptoms as ego-syntonic, as opposed to ego-dystonic, more consistent with impulse control disorders. In support of a potential overlap, Frost et al. (2011) found that up to 78.3% of participants in a primary hoarding sample met clinical criteria for one impulse control disorder. Despite these findings, the direct relationship between impulsivity and hoarding has received little empirical attention. One investigation found that those with primary hoarding showed lower levels of response inhibition, a proxy measure for impulsivity, compared to control samples (Grisham et al., 2007). The role of impulsivity in hoarding has important nosological implications. Although it seems likely that hoarding disorder will be included in the upcoming DSM-5 under the Obsessive–Compulsive and Related Disorders section (American Psychiatric Association), the empirical support for this classification remains unclear. While hoarding might have been traditionally associated with OCD, it is possible that the disorder may have both impulsive and compulsive facets. Consistent with this, researchers have identified a potential category of disorders that appear to have both impulsive and compulsive features at their core, including OCD, Tourettes disorder, ADHD, pathological gambling, and compulsive buying. Familial and comorbidity investigations have revealed that these disorders tend to cluster in families, as well as co-occur within individuals, supporting evidence for shared mechanisms (Hollander et al., 2007; Stein et al., 2010). The current investigation sought to clarify the relationship between hoarding and impulsivity in two cross-cultural, young adult samples. Given that the vast majority of research on hoarding has been conducted in either the U.S. or England, relatively little is known about the nature of hoarding in other cultures. We therefore compared a U.S. sample to a similar and age-matched German sample. Germany was selected given the evidence that (1) hoarding has a similar prevalence rate in Germany and the U.S. (Timpano et al., 2011), and (2) the latent structure of hoarding is the same in the two cultures (Timpano et al., in press). In addition, hoarding has recently received greater scrutiny in Germany (Mueller et al., 2009b), resulting in both the availability of translated measures and a need to better understand this syndrome in that country. The reliance on young adult samples is supported by findings that hoarding symptoms most often emerge prior to the age of 20 (Tolin et al., 2010), as well as taxometric analyses that have examined the latent structure of hoarding (Timpano et al., in press), compulsivity (Olatunji et al., 2008), and impulsivity (Marcus and Barry, 2011). Each of these constructs represents a continuous spectrum, indicating that high scoring individuals do not reflect a discrete taxon and that symptoms are best captured by dimensional measures. Our first aim was to examine the association between impulsivity and hoarding. We utilized both a “classic” measure of impulsivity in Study 1, the Barratt Impulsivity Scale (BIS) (Patton et al., 1995), and a more recent conceptualization of this construct in Study 2, the UPPS Impulsive Behavior Scale (UPPS) (Whiteside and Lynam, 2001). This allows for a more detailed analysis of empirically supported facets of impulsivity. We hypothesized that hoarding symptoms would be associated with greater impulsivity in both the U.S. and German samples. Additionally, we hypothesized that individuals with hoarding symptoms above the mean (high hoarding group) would endorse greater impulsivity than individuals with hoarding symptoms below the mean (low hoarding group), after taking into account theoretically relevant covariates. In both studies we included generalized mood and anxiety symptoms, as well as non-hoarding OCD symptoms as covariates. In Study 1 we also considered alcohol use problems as a covariate, since these symptoms are associated with greater levels of impulsivity (Hawkins et al., 1992), and may be particularly relevant for a college-aged population (Ham and Hope, 2003). Our second aim was to examine the differential predictive power of impulsivity and compulsivity in relation to hoarding symptoms, and after controlling for covariates. We hypothesized that both impulsivity, characterized by either the UPPS or BIS, and compulsivity, characterized by non-hoarding OCD symptoms, would predict hoarding symptoms.