The holidays are peak buying time, and perhaps the worst time of the year for people who simply can't control their urge to shop.
Now, research shows that the ease of online purchasing could be making things worse for people with so-called "buying-shopping disorder" (BSD).
BSD is still debated as a stand-alone diagnosis, and hasn't yet been included in the psychologists' bible, the Diagnostic and Statistical Manual of Mental Disorders.
But that's probably only because not enough good data on the condition exists, said the author of a recent study into online shopping addiction.
There's a "relative lack of published scientific literature," said Dr. Astrid Muller -- but psychologists have long dealt with such cases.
"There is well over 100 years of clinical history describing dysfunctional buying or acquisition excesses that interfere with daily life, and are associated with significant clinical distress and impairment in important areas of functioning," said Muller. She's head psychologist in the department of psychosomatic medicine and psychotherapy at Hannover Medical School in Germany.
BSD is defined as an "extreme preoccupation with shopping and buying [and] to impulses to purchase that are experienced as irresistible," Muller said.
The condition can cause real harm, including post-purchase guilt and regret, a sense of loss of control, family conflict over excessive purchasing, and financial distress.
According to Muller, BSD is thought to affect about 5% of people globally. And in the 21st century, it has moved online.
Reporting in the current issue of Comprehensive Psychiatry, Muller's group tracked the online shopping habits of 122 patients already diagnosed with BSD.
Study patients ranged in age from 20 to 68 (at an average of about 43), and more than 75% were women. All were already seeking treatment -- which usually takes the form of cognitive-behavioral therapy -- for their shopping addiction problem.
Participants were asked to complete a number of diagnostic questionnaires, including the so-called "Internet Addiction Test" and the "Pathological Buying Screener." All were also assessed for anxiety and depression.
In the end the team concluded that a third had developed an online shopping version of BSD. These individuals tended to be younger, and typically had more severe anxiety and depression.
According to Muller, people with BSD may have their reasons for preferring one shopping venue over another.
"Some individuals with BSD may always prefer shopping in brick-and-mortar-based stores because they appreciate the opportunity to touch merchandise, try out goods, enjoy the stimulating traditional retail environment, and experience comfortable social interaction with salespersons," she explained.
But some BSD patients may be especially attracted to online purchases, because shopping via the web involves such a huge variety of products. It's also easy, quick and has "the opportunity to buy unobserved and secretly," Muller said.
"All contribute to the migration of traditional buying-shopping disorder to the online retail market," she concluded.
Dr. Petros Levounis is chair of the department of psychiatry at Rutgers New Jersey Medical School, and chief of service at University Hospital in Newark, N.J. He wasn't involved in the new research, but said any new data on BSD is crucial.
"We're not close to having all the research we would like to have for issues like BSD, which is part of an emerging group of disorders called behavioral addictions," Levounis noted. "These include compulsive suntanning, gambling and compulsive internet gaming. But they also include behaviors that are usually part of everyday life, and which for most people are helpful. Things like exercising, eating, emailing, texting, and, yes, shopping.
"But what we do know is that for people who are addicted these behaviors are like a drug," said Levounis. "And the fewer the barriers to the addictive behavior, the greater the potential for negative consequences.
"So if you have BSD, and you find that you don't have to go to the mall to shop, if everything is just a click away, then that is very, very compelling," he said. "And it certainly has the potential to turn your disorder into even more of a problem than it was before."
There's more information about behavioral addictions at American Addiction Centers.