Sunday, February 7, 2010

A Link Between Autism and Eating Disorders?

The Times in the UK has reported that autism and related conditions are being underdiagnosed in women and teenage girls, with many cases being confused with eating disorders or other problems.

Janet Treasure, an expert on eating disorders at the Institute of Psychiatry, King’s College London, said that women or girls on the autistic spectrum often focused on diet or calorie control, which became their obsession. About one in five women with an eating disorder is thought to be on the autistic spectrum.

A study led by Professor Treasure on 150 women with acute anorexia or bulimia suggests that up to 60 per cent also develop the psychological signs of autism. “Those who are severely underweight and unwell, with serious disruption of eating patterns, share a lot of the cognitive and emotional styles common to autism,” she said. “Their poor nutrition means that they can’t see the bigger picture, they focus on detail and have a rigid way of thinking, finding it hard to adapt.”

These psychological symptoms were lessened when most of the women gained weight. But “girls with autism are at high risk of getting into a pattern of behaviour that can cause a vicious cycle of problems”, said Professor Treasure. “It is important that people notice and try to stop it.”

Mark Lever, the chief executive of the National Autistic Society, said: “We are extremely concerned that many women with autism may be going undiagnosed. So many tell us that trying to get a diagnosis feels like an insurmountable hurdle and they have to fight tremendous battles to get the help, support and services they desperately need.

In April 2009, News Scientist reported that Simon Baron-Cohen of the Autism Research Centre in Cambridge, UK, is also measuring whether adolescents with anorexia score higher on autistic traits than healthy people, as he suspects that some may actually have undiagnosed Asperger's syndrome. "We have always known that Asperger's syndrome was diagnosed more often in males," he says. "The new question is whether it takes a different form in females, and can account for at least a subgroup of those who are diagnosed with anorexia."

If it does, this could have important implications for the way that anorexia is treated. "As well as treating the 'eating disorder' the clinician and the patient might [also] focus on social skills," says Baron-Cohen, although he adds that weight gain would remain a key target.

An article in Time in June 2009 reported that London researchers have been studying the commonalities between these two conditions for several years. On the surface, they appear entirely different — in autism, patients have difficulty connecting with people in the outside world, while in anorexia, sufferers seem consumed by other people's perceptions — but Maudsley researchers point out that the salient characteristics of each illness are similar.

For example, both anorexic and autistic patients have a tendency to behave obsessively and suffer from rigid ways of thinking. Tic disorders, which commonly affect people with autism, are found in 27% of people with severe anorexia. And in both conditions, patients have difficulty with "set-shifting," or changing course mentally.

The same article states that according to Dr. Eric Hollander, an attending psychiatrist at Montefiore Medical Center in New York City and an expert on autism, there is evidence that the "repetitive thoughts and behaviors, rigid routines and rituals and perfectionism" that characterise both autism and anorexia may be traced to the same regions in the brain.

If this is in fact the case, it would be beneficial to conduct further research into the link between anorexia and autism. Simon Baron-Cohen makes a valid point about using this information to reassess the way anorexia could potentially be treated.

1 comment:

  1. Thanks for an interesting post. A couple studies show that some of the cognitive traits associated with anorexia nervosa improve with normalization of eating and healthy body weight, pointing to the importance of addressing starvation for psychological, as well as physical health.

    Psychosom Med. 2010 Jan;72(1):73-9. Epub 2009 Dec 7.
    Emotional theory of mind and emotional awareness in recovered anorexia nervosa patients.
    Oldershaw A, Hambrook D, Tchanturia K, Treasure J, Schmidt U.

    King's College London, Institute of Psychiatry, Division of Psychological Medicine and Psychiatry, Section of Eating Disorders, London, SE5 8AF, UK.
    OBJECTIVES: To examine whether an impaired ability to infer emotion in people with autism spectrum disorder (ASD) and difficulty with emotional theory of mind (eToM) are limited to the ill state or if this condition is a stable deficit that persists with recovery in adults with anorexia nervosa (AN). This is in keeping with observations of similarities between the disorders. METHODS: Twenty-four participants fully recovered from AN were compared against a sample of currently ill AN patients (n = 40) and healthy controls (HCs) (n = 47) on forced-choice tasks assessing emotion recognition, basic or advanced eToM in other people, using sensory stimuli and on a written task measuring eToM ability for the self as well as for others. RESULTS: Recovered participants performed well on eToM tasks and were significantly better than currently ill patients at inferring emotions in the self and in others. However, participants recovered from AN had some slight impairment in emotion recognition relative to HCs, particularly when recognizing positive emotions. CONCLUSIONS: These findings indicate almost complete normalization of emotion recognition ability as well as the restoration of eToM in recovered patients, despite the observation of difficulties in both domains in currently ill patients. Findings suggest that similarities between AN and ASD in poor eToM are restricted to the currently ill AN state and such difficulties in AN may be a factor of starvation.

    Int J Eat Disord. 2009 May 11. [Epub ahead of print]
    In first presentation adolescent anorexia nervosa, do cognitive markers of underweight status change with weight gain following a refeeding intervention?
    Hatch A, Madden S, Kohn MR, Clarke S, Touyz S, Gordon E, Williams LM.

    The Brain Dynamics Centre, Westmead Millennium Institute and University of Sydney, Westmead Hospital, Westmead, Sydney, New South Wales, Australia.
    OBJECTIVE:: To determine the nature and severity of cognitive functioning impairment in adolescent anorexia nervosa (AN) when underweight and following weight gain. METHOD:: In 37 first admission adolescent (12-18 years) AN patients and 45 matched controls, general cognitive functions were assessed at baseline and follow-up using the IntegNeuro-computerized battery. AN participants were tested between days 3 and 10 of their admission when underweight, with retesting conducted after weight restoration. RESULTS:: When underweight, AN participants performed more poorly than controls on sensori-motor speed tasks and exhibited a susceptibility to interference, but had superior working memory. Once the weight is restored, individuals significantly improved relative to their own performance. Relative to controls, they were significantly faster on attention and executive function tasks, exhibited superior verbal fluency, working memory, and a significantly superior ability to inhibit well-learnt responses. DISCUSSION:: Cognitive impairments in adolescent AN appear to normalize with refeeding and weight gain. (c) 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2009.