Creating and Classifying New Impulse-Control Disorders

Director, Principal Investigator, Seaver and New York Autism Center of Excellence, Esther and Joseph Klingenstein Professor & Chair of Psychiatry, Mt. Sinai School of Medicine

This interview was conducted by Peter Cook on November 22, 2006

Introduction

Although the realization of DSM-V is still some years away, planning meetings are already well underway, and among the proposed changes suggested is a new, broad category of conditions: the behavioral and substance addictions. The new category would comprise current impulse-control and substance-abuse disorders, as well as 4 new impulse-control disorders that have recently garnered increased attention: compulsive shopping, compulsive internet use, compulsive sexual behavior, and psychogenic excoriation (skin-picking). One proponent of the addition is Dr. Eric Hollander. “I’ve had an interest for some years now in impulsivity as a symptom domain that cuts across or drives a number of conditions,” Dr. Hollander explains. “There is a characteristic pattern in impulse-control disorders: people act on impulse to receive pleasure or gratification, their so acting reduces the arousal, and they feel guilt or remorse afterward. These behaviors can become repetitive or driven over time, and all share similar phenomenology, course of illness, treatment response, familiality, genetic factors, and brain circuits.” The underlying idea supporting the new, inclusive category, he says, is that many impulse disorders share basic characteristics with substance-abuse disorders.

Impulse-Control Disorders

Of late, evidence has mounted that compulsive shopping, specifically, is far more common than previously believed, and leads to substantial functional impairment. A study by Larry Koran, MD, and colleagues, in the October issue of the American Journal of Psychiatry (http://ajp.psychiatryonline.org/cgi/content/abstract/163/10/1806), found that individuals with shopping behavior 2 standard deviations above the mean had an increased probability for divorce and bankruptcy.

While consensus is growing that impulse-control disorders such as compulsive shopping are serious and in need of recognition, there continues to be debate on how best to categorize these newly proposed disorders. “Although it’s called compulsive shopping or buying, the disorder shares certain features with OCD and a suggested grouping for DSM-V of obsessive-compulsive related disorders,” Dr. Hollander says. “However, many people still don’t really understand that compulsivity and impulsivity are two sides of the same coin. Further, there’s reason to believe that impulse-control disorders such as compulsive shopping will prove useful as “clean” models for researching the pathophysiology and etiology of substance disorders.” Dr. Hollander and many of his colleagues believe it will be easier, and more fruitful from a research standpoint, to include impulse-control disorders with the substance disorders as opposed to the obsessive-compulsive related disorders in DSM-V.

A Valid Diagnosis?

“Originally, there was discussion on whether it made sense to create diagnostic criteria for a disorder the primary symptoms of which are common traits in the general population,” Dr. Hollander says. “Almost everyone shops, so the worry is that creating a disorder where shopping is the symptom could trivialize the condition and/or medicalize a part of human nature.” Some also suggested that the creation of a compulsive shopping diagnosis could be either driven by—or appear to be driven by—ulterior motive. Both clinicians and the pharmaceutical industry stand to benefit from the creation of new disorders. “There are always possible downsides to creating any new condition,” Dr. Hollander says, “but these same sorts of arguments have been leveled against social anxiety disorder and ADHD. ADHD is still not fully recognized in Europe, in fact. In the end, when a disorder is common and is associated with significant functional impairment—as is the case with compulsive shopping—the benefits of officially recognizing it outweigh the detriments.”

Compulsive shopping is surprisingly common, affecting 5%–6% of the population, or possibly an even greater percentage, depending on where the diagnostic threshold is set. “If we create a diagnosis for this disorder, then it will be screened for in a more systematic fashion, not only by clinicians, but in large scale epidemiological surveys as well,” Dr. Hollander says. “Then we’ll be able to determine in a reliable fashion how prevalent the disorder truly is. Larger studies will also help us better understand the pathophysiology of the disorder; researchers may be able to identify brain circuits associated with the disorder, or strong familiality, or identifiable genetic factors. There are likely brain-based changes associated with detrimental compulsive behavior, and they may be related to changes in substance-abuse disorders. Further, if specific, effective treatment is identified, it becomes even more important to diagnose these disorders. The bottom line must be to help the patient.”

Dr. Hollander also stresses the importance of establishing a discontinuity between traits common in the general population and symptoms of a necessary severity to merit a diagnosis. “We all shop, but, for most of us, shopping does not have both immediate and long-term deleterious effects on our lives. Proper diagnostic criteria would clearly delineate between trivial and severe symptoms.”

Treatment

Studies have shown some benefit from serotonin reuptake blockers in patients with compulsive shopping disorder, and studies are also underway with escitalopram. A number of studies examining pathological gambling have suggested that there may be different developmental trajectories to impulsivity, or different comorbid conditions that frequently co-occur with impulse-control disorders, that may to some extent shape the expression of, or modify treatment response in, these conditions, says Dr. Hollander. “Individuals who have a lot of compulsive and anxiety features seem to respond well to serotonin reuptake inhibitors. Those with some evidence for mood instability or a family history of bipolar-like symptoms tend to have preferential responses to mood stabilizers like lithium or valproate. Those individuals with family histories of addiction may benefit most from opiate antagonist treatments like naltrexone or nalmefene. Finally, those with comorbid ADHD may find a stimulant helpful for impulsivity.”

Conclusion

Dr. Hollander believes that there is solid support for creating a category of behavioral and substance addictions, and equally solid support for fleshing out diagnostic criteria for the 4 new impulse-control disorders not currently specified. Newly identified impulse-control disorders, such as compulsive shopping, are prevalent and are paired with significant functional impairment. Formal diagnostic criteria will lead to a better understanding, and, in the long-term, better treatment for patients suffering from these disorders. Finally, there is hope that the impulse-control disorders will be of use in researching the pathophysiology of substance-abuse disorders. “The same basic brain systems seem to be involved,” Dr. Hollander says. “It’s just the salient environmental factors that are different. Compulsive shoppers are less likely than drug-users to be taking substances that alter brain-circuitry, so they present a cleaner model for study.”

Disclosure: Dr. Hollander is on the advisory boards of Abbott, Ortho-McNeil, and Wyeth; and receives grant support from Abbott, Eli Lilly, Janssen, NIDA, NIMH, NINDS, OPD-FDA, Ortho-McNeil, Pfizer, Solvay, UCB Pharma, and Wyeth.