New research on rats seems to find a connection between yo-yo dieting and compulsive eating.
According to researchers at the Boston University School of Medicine (BUSM), a chronic cyclic pattern of overeating followed by undereating reduces the brain’s ability to feel reward and may drive compulsive eating.
The finding suggests that future research into the treatment of compulsive eating behavior should focus on rebalancing the mesolimbic dopamine system, the part of the brain responsible for feeling reward or pleasure, researchers say.
“We are just now beginning to understand the addictive-like properties of food and how repeated overconsumption of high sugar — similar to taking drugs — may affect our brains and cause compulsive behaviors,” said corresponding author Pietro Cottone, Ph.D., an associate professor of pharmacology and experimental therapeutics at BUSM and co-director of the Laboratory of Addictive Disorders.
To better understand compulsive and uncontrollable eating, Cottone and his research team performed a series of experiments on two groups of rats. One, the cycled group, received a high-sugar, chocolate-flavored diet for two days each week and a standard control diet the remaining days of the week, while the control group received the control diet all of the time.
The group that cycled between the palatable food and the less palatable food spontaneously developed compulsive, binge eating on the sweet food and refused to eat regular food, the researchers discovered.
Both groups were then injected with a psychostimulant amphetamine, a drug that releases dopamine and produces reward, and their behavior in a battery of behavioral tests was then observed.
While the control group predictably became very hyperactive after receiving amphetamine, the cycled group did not.
Furthermore, in a test of the conditioning properties of amphetamine, the control group was attracted to environments where they previously received amphetamine, whereas the cycled group were not.
Finally, when measuring the effects of amphetamine while directly stimulating the brain reward circuit, the control group was responsive to amphetamine, while the cycled group was not, according to the findings.
After investigating the biochemical and molecular properties of the mesolimbic dopamine system of both groups, the researchers determined that the cycled group had less dopamine overall, released less dopamine in response to amphetamine, and had dysfunctional dopamine transporters — proteins that carry dopamine back into brain cells — due to deficits in the mesolimbic dopamine system.
“We found that the cycled group display similar behavioral and neurobiological changes observed in drug addiction: specifically, a crash in the brain reward system,” Cottone said. “This study adds to our understanding of the neurobiology of compulsive eating behavior.
“Compulsive eating may derive from the reduced ability to feel reward. These findings also provide support to the theory that compulsive eating has similarities to drug addiction.”
“Our data suggest that a chronic cyclic pattern of overeating will reduce the brain’s ability to feel reward — feeling satiated. This results in a vicious circle, where diminished reward sensitivity may in turn be driving further compulsive eating,” said lead author Catherine (Cassie) Moore, Ph.D., a former graduate student in the Laboratory of Addictive Disorders at BUSM.
The study was published in the journal Neuropsychopharmacology.
Source: Boston University School of Medicine
A new Swedish study suggests children with inflammatory bowel disease (IBD) have a greater risk for psychiatric disorders. Researchers believe that more psychological support and longer follow-up is needed for the children affected and their parents.
Investigators explain that it is already known that adults with IBD (ulcerative colitis or Crohn’s disease) run an increased risk of psychiatric disorders. Now their new study shows that children with IBD also run a higher risk of mental health problems.
The research by investigators at the Karolinska Institutet in Sweden appears in JAMA Pediatrics.
For the study, Karolinska scientists assessed more than 6,400 children with IBD, born between 1973 and 2013. Using population registers, the researchers compared the risk of psychiatric disorders later on in life with both healthy children from the general population and with the patients’ own siblings.
Investigators believe the study methodology which compared patients with their siblings, allowed precise analysis of a large number of so-called confounders. Confounders such as socioeconomics, lifestyle and heredity are factors that are known to affect the risk of psychiatric disorders in children.
During an average follow-up period of 9 years, approximately 17 percent of the children with IBD were given a psychiatric diagnosis compared with just under 12 percent of the healthy children and about 10 percent of the siblings.
This means that the risk of psychiatric disorders was 1.6 times higher in children with IBD compared to Swedish children from general population. Likewise, the risk for the children with IBD was greater than for their siblings.
The higher risk applied to a number of psychiatric diagnoses such as depression, anxiety, eating disorders, personality disorders, ADHD and autism spectrum disorder. There was also a higher risk of suicide attempt after reaching adulthood.
“The study shows that children with IBD and their parents are in need of psychological support and longer follow-up,” said Dr. Agnieszka Butwicka, a researcher at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet.
“Special help could be offered to children who become ill at a young age and to children of parents with mental health problems.”
Investigators discovered the risk of mental health problems was greatest during the first year with IBD. The risk was particularly high for children who were diagnosed with IBD before the age of 6 years and for children of parents with psychiatric disorders.
However, although the study is an observation study an absolute link cannot be identified with certainty. Nevertheless, the results do indicate that IBD contributes to mental health problems.
“Because the risk for these children is higher compared with their own siblings, it is likely that it is IBD affecting their mental health rather than other factors such as socioeconomics, lifestyle or heredity in the family,” said Dr. Jonas F. Ludvigsson, a professor in the Department of Medical Epidemiology and Biostatistics.
Source: Karolinska Institute
New international research suggests factors that increase the risk of anorexia are likely to be metabolic as well as psychological. The new findings give hope to patients and their families as discovery of the linkage will provide new direction to clinicians and scientists looking for better treatments for the disease.
University of Otago, Christchurch researchers in New Zealand discovered some people are born with a biological predisposition to developing anorexia and that the disease affects the function of the brain as well as the metabolic system.
Investigators believe considering both genetic and biological factors will help clinicians and scientists develop better treatments for the disease with the highest mortality rate of any psychiatric disorder.
The findings, which appear in Nature Genetics, suggest people are born with a biological predisposition to developing the disease that affects function of the brain as well as the metabolic system.
Anorexia Nervosa Genetics Initiative (ANGI) researchers sampled the DNA of almost 17,000 patients and compared this with over 55,000 control cases (without anorexia nervosa) recruited from 17 countries across North America, Europe and Australia.
The lead researcher was Professor Cynthia Bulik, from the University of North Carolina and the Karolinska Institute (Sweden), who worked with more than 100 other scientists. Lead researchers from New Zealand included Dr. Jenny Jordan and genetics Professor Martin Kennedy.
The ANGI team found eight genetic variants significantly associated with anorexia nervosa, showing the origins of this serious disorder appear to be both metabolic and psychological. The researchers also found:
• The genetic basis of anorexia nervosa overlaps with traits associated with people’s ability to metabolize fats and sugars, and body mass index.
• Genetic factors associated with anorexia nervosa influence physical activity, which could explain the tendency for people with anorexia nervosa to be highly active despite their low-calorie intake.
• The genetic basis of anorexia nervosa overlaps with other psychiatric disorders such as obsessive-compulsive disorder, depression, anxiety, and schizophrenia.
Dr. Jordan says current treatments for anorexia nervosa are primarily psychological therapies that help patients with the critical but difficult task of regaining weight and re-establishing normal eating. There are no specific medications for anorexia nervosa.
“The ANGI findings give us a new way of looking at this disease. For example, many people diet but only a few develop anorexia nervosa with very low levels of weight and sometimes extreme levels of exercise.
The findings that there are genetic differences relating to metabolism in people with anorexia in our study helps make sense of that. It may also help explain in part why recovery is such a struggle. These findings, that it is not just a psychiatric condition, will be hugely validating for many with anorexia nervosa and their families” explains Jordan.
University of Otago, Christchurch’s Professor Martin Kennedy says the findings indicate that people are born with a genetic predisposition for developing the disease. What this means is that they are more prone to developing the disorder, although not everyone with those patterns of DNA will do so.
“Our hope is these fundamental genetic insights will point to better ways of preventing the disorder, and better medications that target the underlying biology. Nobody chooses to succumb to this awful disease, and we need these kinds of new insights to help people survive and move on with their lives.”
Source: University of Otago
A new study shows what happens in the brain when we give up.
The findings, published in Cell, offer new insight into the complex world of motivation and reward.
According to researchers, their findings could help people find motivation when they are depressed, as well as decrease motivation for drugs and other addictive substances.
Researchers at the University of Washington School of Medicine and Washington University School of Medicine, as well as colleagues at other universities, spent four years looking at the role of nociceptin in regulating motivation in mice.
Inside the brain, a group of cells known as nociceptin neurons get very active before a mouse’s breakpoint. They emit nociceptin, a complex molecule that suppresses dopamine, a chemical associated with motivation.
The nociceptin neurons are located near an area of the brain known as the ventral tegmental area. The VTA contains neurons that release dopamine during pleasurable activities.
Although scientists have previously studied the effects of fast, simple neurotransmitters on dopamine neurons, the new study is among the first to describe the effects of this complex nociception modulatory system, according to researchers.
“We are taking an entirely new angle on an area of the brain known as VTA,” said co-lead author Christian Pedersen, a fourth-year Ph.D. student in bioengineering at the University of Washington School of Medicine and the UW College of Engineering. “The big discovery is that large complex neurotransmitters known as neuropeptides have a very robust effect on animal behavior by acting on the VTA.”
The discovery came by looking at the neurons in mice seeking sucrose. The mice had to poke their snout into a port to get sucrose. At first it was easy, then it became two pokes, then five, increasing exponentially, and so on. Eventually, all the mice gave up, the researchers reported.
Neural activity recordings revealed that these “demotivation” or “frustration” neurons became most active when mice stopped seeking sucrose.
In mammals, the neural circuits that underlie reward seeking are regulated by mechanisms to keep homeostasis, the tendency to maintain internal stability to compensate for environmental changes.
In the wild, animals are less motivated to seek rewards in environments where resources are scarce. Persistence in seeking uncertain rewards can be disadvantageous due to risky exposure to predators or from energy expenditure, the researchers noted.
Deficits within these regulatory processes in humans can manifest as behavioral dysfunctions, including depression, addiction, and eating disorders, the researchers add.
According to senior author Dr. Michael Bruchas, a professor of anesthesiology, pain medicine, and pharmacology at the University of Washington School of Medicine, the findings could go a long way towards finding help for patients whose motivation neurons are not functioning correctly.
“We might think of different scenarios where people aren’t motivated, like depression, and block these neurons and receptors to help them feel better,” he said. “That’s what’s powerful about discovering these cells. Neuropsychiatric diseases that impact motivation could be improved.”
Looking to the future, these neurons could perhaps be modified in people seeking drugs or those who have other addictions, he added.
Source: University of Washington
Photo: At the point of giving up, neurons in green get very active and suppress dopamine, a chemical associated with motivation, researchers found. Credit: Max Huffman.
A new study finds that atypical eating behaviors were present in 70 percent of children with autism, 15 times more common than in neurotypical children. Researchers from Penn State College of Medicine believe the association suggests a child with unusual eating behaviors should be screened for autism.
Dr. Susan Mayes, a professor of psychiatry, said atypical eating behaviors may include severely limited food preferences, hypersensitivity to food textures or temperatures, and pocketing food without swallowing.
According to Mayes, these behaviors are present in many 1-year-olds with autism and could signal to doctors and parents that a child may have autism.
“If a primary care provider hears about these behaviors from parents, they should consider referring the child for an autism screening,” Mayes said.
Mayes said that the earlier autism is diagnosed, the sooner the child can begin treatment with a behavior analyst.
Previous studies have shown applied behavior analysis to be most effective if implemented during the preschool years. Behavior analysts use a number of interventions, including rewards, to make positive changes in the children’s behavior and teach a range of needed skills.
Dr. Keith Williams, director of the Feeding Program at Penn State Children’s Hospital, uses this form of therapy to help a variety of individuals with unusual eating behaviors. He said that identifying and correcting these behaviors can help ensure children are eating a proper diet.
“I once treated a child who ate nothing but bacon and drank only iced tea,” Williams said. “Unusual diets like these don’t sustain children.”
Williams also noted that there is a distinct difference between worrisome eating behaviors and the typical picky eating habits of young children. He explained that most children without special needs will slowly add foods to their diets during the course of development, but children with autism spectrum disorders, without intervention, will often remain selective eaters.
“We see children who continue to eat baby food or who won’t try different textures,” Williams said. “We even see children who fail to transition from bottle feeding.”
Mayes said that many children with autism eat a narrow diet consisting primarily of grain products, like pasta and bread, and chicken nuggets. She said that because children with autism have sensory hypersensitivities and dislike change, they may not want to try new foods and will be sensitive to certain textures. They often eat only foods of a particular brand, color or shape.
The research also showed that most children with autism who had atypical eating behaviors had two or more types; almost a quarter had three or more. Yet, none of the children with other developmental disorders who did not have autism had three or more.
According to Williams, this is a common, clinical phenomenon, and it has prompted him and his colleagues to recommend some children for further evaluation.
“When we evaluate young children with multiple eating problems, we start to wonder if these children might also have the diagnosis of autism,” Williams said. “In many cases, they eventually do receive this diagnosis.”
For the research, investigators evaluated the eating behaviors described in parent interviews of more than 2,000 children from two studies. They assessed the difference in the frequency of unusual eating behaviors between typical children and those with autism, attention deficit hyperactivity disorder and other disorders.
Williams said the study data shows that atypical eating behaviors may help diagnostically distinguish autism from other disorders. Even though children from both groups have unusual eating habits, they are seven times more common in autism than in other disorders, according to the study data.
“This study provided further evidence that these unusual feeding behaviors are the rule and not the exception for children with autism,” Williams said.
Source: Penn State
A new large-scale data study in the UK provides clarity on early warning signs associated with an eating disorder. Swansea University researchers believe their findings will help primary care physicians detect eating disorders earlier in the course of care.
Investigators discovered that people diagnosed with a disorder had higher rates of other conditions and of prescriptions in the years before their diagnosis. The study appears in the British Journal of Psychiatry.
In the UK eating disorders such as anorexia nervosa, bulimia nervosa and binge eating disorder affect an estimated 1.6 million people. In the U.S., more than 10 million people are affected although the true figures may be higher, as many people do not seek help.
Experts explain that eating disorders predominantly affect women but men are not without risk. Most people are diagnosed during adolescence and early adulthood. Eating disorders have the highest mortality of all mental illnesses, both from physical causes and from suicide.
Yet despite the scale of the problem, resources to treat eating disorders are scarce. There are very few specialized treatment centers. People affected are often young and vulnerable, and may avoid detection. However, the earlier a disorder can be diagnosed, the better the likely outcome for the patient.
Investigators believe this is an area where the new findings can make a big difference. The new knowledge can help primary care physicians understand what could be early warning signs of a possible eating disorder.
The research team, from Swansea University Medical School, examined anonymized electronic health records from primary care practices and hospital admissions in Wales. 15,558 people in Wales were diagnosed as having eating disorders between 1990 and 2017.
In the two years before their diagnosis, data shows that these 15,558 people had:
- higher levels of other mental disorders such as personality or alcohol disorders and depression;
- higher levels of accidents, injuries and self-harm;
- higher rates of prescription for central nervous system drugs such as antipsychotics and antidepressants, and;
- higher rates of prescriptions for gastrointestinal drugs (e.g. for constipation and upset stomach) and for dietetic supplements (e.g. multivitamins, iron).
Therefore, looking out for one or a combination of these factors can help physicians identify eating disorders early.
Dr. Jacinta Tan, an associate professor of psychiatry at Swansea University led the research. Tan is also a consultant child and adolescent psychiatrist. She comments:
“I cannot emphasize enough the importance of detection and early intervention for eating disorders. Delays in receiving diagnosis and treatment are sadly common and also associated with poorer outcomes and great suffering,” she said.
“This research contributes to the evidence about prevalence of eating disorders and begins to quantify the scale of the problem in the entire country of Wales. The majority of these patients we identified are not known to specialist eating disorder services.
“The increased prescriptions by GPs both before and after diagnosis indicates that these patients, even if not known to specialist services, have significantly more difficulties or are struggling. This underlines the clinical need for earlier intervention for these patients and the need to support GPs in their important role in this.”
Dr. Joanne Demmler, senior data analyst in the National Centre for Population Health and Wellbeing Research, based at Swansea University, noted, “This has been an absolutely fascinating project to work on. We used anonymized clinical data on the whole population of Wales and unraveled it, with codes and statistics, to tell a story about eating disorders.
This ‘storytelling’ has really been an intricate part of our understanding of this extremely complex data and was only possible through a very close collaboration between data analysts and an extremely dedicated and enthusiastic clinician.”
Source: Swansea University/EurekAlert