BARCELONA, Spain ― Binge eating disorder (BED) is part of the recently published fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), marking its first appearance in any DSM. But what about binge eating obesity ― is it a type of food addiction? Should it be added to the next version of the DSM? Or is food addiction itself even a real disorder?
These are just some of the questions that were brought up during a presentation here at the 26th European College of Neuropsychopharmacology (ECNP) Congress.
Suzanne L. Dickson, PhD, told meeting attendees that because obesity has reached global epidemic proportions, there is an urgent need for understanding the mechanisms for uncontrolled food intake.
She noted that recent data have suggested that brain reward pathways that are involved in alcohol and drug addiction are also essential elements of the ghrelin responsive circuit. And ghrelin has been shown to both signal hunger and increase food intake.
"Based on these and other recent findings, could obesity be a food addiction? A subgroup of obese patients indeed show 'addictivelike' properties with regard to overeating…but this does not automatically mean they are addicted," said Dr. Dickson, who is a neuroscientist at the Sahlgrenska Academy at the University of Gothenburg, Sweden.
After the presentation, she told Medscape Medical News that more evidence is needed.
"Food consumption, unlike alcohol, cocaine, or gambling or Internet gaming behaviors, is necessary for survival. But we don't completely understand why certain vulnerable individuals become addicted, transferring something rewarding to becoming addicted to it. For drugs, it's much easier to separate what's going on," said Dr. Dickson.
"For now, we need to ask: in our modern environment where food is so plentiful, has food no longer become our friend when it is something we can become addicted to?"
More Research Needed
Dr. Dickson noted that past research has shown that 10% to 20% of obese individuals have BED, but the disorder also often occurs in people of normal weight.
The term "food addiction" was created by the media and some sufferers to better explain certain behaviors, and more research is needed to support adding the term as a formal diagnostic category, she added.
"The evidence itself is insufficient to support the idea that food addiction is a mental disorder. We do not have a clinical syndrome of food addiction so far, and it is very important to establish the validity of a condition before putting it forward for inclusion in the DSM."
Still, she pointed out that recognizing certain behaviors (such as gambling) as addiction is "a major step forward" and should help decrease stigma for these people.
Dr. Dickson is currently the coordinator for her university's integrated Neurobiology of Food Intake, Addiction, and Stress (NeuroFAST) project. One of the areas that NeuroFAST has looked into is the impact of palatable foods, such as chocolate, on brain centers involved in reward and addiction. They have compared overeating with drug addiction to try to answer whether obesity could result from a food addiction that resembles an addiction to drugs and/or alcohol.
"We had to ask if the evidence supports food addiction for more than a small proportion of the population," added Dr. Dickson.
"But I have to say that in man, there is no solid evidence that any food, ingredient, combination of ingredients, or additive (with the exception of caffeine) causes us to become addicted to it. That is different from drugs, which we know engage the brain and cause us to become addicted to them," she explained.
"Still, if we move away from food and concentrate on the individual, we can see that certain obese individuals express addictionlike behaviors."
Dr. Dickson went on to mention that a study published inthe Archives of General Psychiatry in 2011 discussed the Yale Food Addiction Scale, with validation from functional magnetic resonance imaging (fMRI).
"Looking at the brain response to anticipating or receiving a chocolate milk shake, they found some evidence that those patients who had a high food addiction scale rating had different responses to the drink than did those who had a low rating. But where are the cutoffs if we are going to use fMRI to help us?" she asked.
"I think increased research into BED and food addiction is needed, and it will facilitate new diagnosis and therapeutic advances for obesity prevention and treatment," she concluded.
"Stop Speculating and Overdiagnosing"
"I think from the perspective of DSM and diagnosis and classification, the main message for clinicians is to stop speculating and overdiagnosing things like food addiction or food disorders," session moderator Hans-Ulrich Wittchen, PhD, from the Institute of Clinical Psychology and Psychotherapy at the Technical University of Dresden, Germany, told Medscape Medical News.
"It's too early. It's premature. It should be limited to what we know. And that is: binge eating is a stable behavior, and there should be intervention. Whether this is a behavioral eating disorder or part of a food addiction syndrome that we might diagnose in 10 to 15 years from now, we don't know," he added.
Dr. Wittchen, who was not involved with Dr. Dickson's presentation or research, was involved with the development of DSM-5.
"Eating disorders are considered more behavioral syndromes. The question is: does the fact that many of the eating disorders show many of the same compulsive and addictivelike behaviors justify putting them into the substance group in the manual?"
He noted that it is more important to find out what is going on with a particular patient instead of "getting caught up in semantics."
"It's difficult to say whether any of these food components have created some disturbance that would justify calling it addiction. Is this a brain disease by definition? I don't think so. That goes too far," he said.
"I think we should just understand what we can do to improve suffering in all of our patients."
In a press release, Hisham Ziauddeen, PhD, from the Wellcome Trust–Medical Research Council Institute of Metabolic Science at Addenbrooke's Hospital at the University of Cambridge in the United Kingdom, agreed with Dr. Wittchen overall. He noted that although the idea of food addiction is appealing, there is little evidence so far showing that it exists in humans.
"It is a very important idea to explore, but it is essential that we have sufficient research to conclusively support it before we hurry to recognize it as a genuine condition and start thinking of ways to tackle and treat it," he said.
Health Policy Implications
Still, Ashley Gearhardt, PhD, assistant professor of clinical psychology at the University of Michigan in Ann Arbor, noted in the same release that giving food addiction a formal diagnosis could someday lead to important implications for healthcare policy.
Dr. Gearhardit was lead author of the Yale Food Addiction Scale study mentioned earlier by Dr. Dickson and spoke at a later symposium at the conference about food addiction and BED.
"The idea that certain foods might be able to trigger an addictive process in vulnerable individuals is a hotly debated topic. If food addiction exists, it may alter the way we think about the role of the brain in obesity, which might open up development of novel pharmaceutical treatments," she said.
"Policy successes and failures from the addiction field might also guide approaches to this worldwide public health crisis."
26th European College of Neuropsychopharmacology (ENCP) Congress. Press briefing given October 7, 2013.
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Cite this: Is 'Food Addiction' Real? - Medscape - Oct 16, 2013.