MIAMI — Compulsive hoarding occurs across disorders, according to a community-solicited study of people who reported hoarding behaviors and a wide range of comorbidities.
Traditionally, researchers assess a group of people with obsessive-compulsive disorder (OCD) and determine which ones endorse compulsive hoarding. In fact, hoarding is the most consistent and distinct subtype of OCD reported, Randy O. Frost, Ph.D., said at the annual conference of the Anxiety Disorders Association of America.
Studies using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) find that 7%–54% of OCD patients endorse hoarding, but more recent evidence suggests a distinction between the two (Clin. Psychol. Rev. 2004;24:283–313). A stronger co-occurrence of certain OCD symptoms, such as contamination and rituals, relative to hoarding, supports this theory (Behav. Res. Ther. 2005;43:897–921).
Dr. Frost and an associate performed a previous study and found “anxiety plays a smaller role in hoarding than in OCD, which is another reason we think they might be distinct” (Behav. Res. Ther. 2003;41:179–94). Dr. Frost is the Harold Edward and Elsa Siipola Israel Professor of Psychology at Smith College in Northampton, Mass.
Frequency of hoarding in populations with DSM-IV diagnoses is pretty high (OCD, dementia, schizophrenia, brain injury, etc.).
“No studies have examined diagnoses in samples of people who hoard—flipping it the other way around,” Dr. Frost said. So instead of looking for compulsive hoarding within a subset of people with OCD, he and his associates assessed a sample of 75 self-reported compulsive hoarders for OCD and other comorbidities. They specifically looked for anxiety, impulse control, and personality disorders in a sample not recruited from an anxiety clinic.
Most of the participants (75%) were female, and the mean age was 53 years. “We frequently see an older population when we solicit for hoarding versus other anxiety disorders,” Dr. Frost said.
In addition to a home visit, researchers assessed all participants with the expanded Anxiety Disorder Interview Schedule (ADIS-Lifetime) and the Saving Inventory-Revised (SI-R). In 35 of the patients, they also used the Structured Clinical Interview for DSM-III-R (SCID-II) and the Minnesota Impulsive Disorders Interview (MIDI).
“Only 31% of this hoarding sample had any clinically significant OCD symptoms, and another 16% had subclinical symptoms,” Dr. Frost said. “The rest look like what we might call 'pure hoarders.'”
A total of 31% met criteria for major depressive disorder, 25% for general anxiety disorder, and 16% for generalized social phobia, “which was still significant,” Dr. Frost said.
“When we look at the frequency of axis II diagnoses in hoarding, it is much smaller than we might expect given the general assumptions about hoarding,” Dr. Frost said. In this study, for example, 31% had an axis II personality disorder, such as obsessive-compulsive personality disorder.
More than 70% of the sample endorsed compulsive acquisition. This finding was a composite of 60% who reported compulsive buying behavior and 51% who reported compulsive acquisition of free items.
A total of 92% scored high for compulsive acquisition on a subscale of the SI-R (SI-R-acquisition). This was the percentage that exceeded by at least one standard deviation the mean acquisition score of 6.9 among a normal sample. Regarding the SI-R-clutter subscale, 96% of the participants exceeded the mean score of 12.8. Regarding the SI-R-difficulty discarding measure, 95% exceeded the mean score of 8.2. “We are seeing these things are very prevalent in this sample who hoard,” Dr. Frost said.