PET Findings in Compulsive Hoarding

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Summary and Comment

PET Findings in Compulsive Hoarding

Individuals with OCD and prominent hoarding symptoms demonstrated a characteristic metabolic pattern, suggesting that these patients form a neurobiologically distinct OCD subgroup.

In 10% to 20% of patients with obsessive-compulsive disorder, the most prominent symptom is hoarding, which is now being delineated as a clinically distinct subtype of OCD (see Journal Watch Psychiatry Jul 22 2004). Hoarders are less responsive to SSRIs and cognitive-behavioral therapy than other OCD patients and have genetically distinct transmission patterns. Characteristics of compulsive hoarding include saving, collecting, perfectionism, disorganization, and procrastination; indecisiveness and avoidance are also often present. All of these may contribute to the "default" behavior of not throwing things away. Drawing retrospectively on data from a comparison of OCD and depression, researchers analyzed PET scans from 45 medication-free OCD patients and 17 normal controls. In 12 patients, the most prominent OCD symptom was hoarding; hoarding patients were significantly older than nonhoarders and controls.

Hoarding patients showed a characteristic metabolic pattern, with significantly lower metabolic activity in the right posterior cingulate gyrus and occipital cortex than controls, and with significantly lower metabolic activity in the dorsal anterior cingulate gyrus and the right sensory motor cortex than nonhoarding OCD patients.

Comment: These authors had to adjust for depression severity, age, and scanner type because these data were drawn from an earlier study on OCD and depression, the groups had significant age differences, and two PET scanners were used. Thus, the findings require confirmation. Despite these shortcomings, the findings are consistent with the phenomenologic distinctions, suggesting that OCD hoarders may form a neurobiologically separate subgroup.

— Joel Yager, MD

Published in Journal Watch Psychiatry July 22, 2004