Scientists could soon help 'cure' anorexia using an already available drug

Anyone who’s suffered from an eating disorder, or knows someone who has, understands what an earth-shattering effect it can have.

More than one person dies every hour as a result of an eating disorder in the US, according to the National Association of Anorexia Nervosa and Associated Disorders (ANAD). This equates to more than 10,000 deaths a year in America alone.

Meanwhile, in the UK, some 1.25 million people are believed to be blighted by this family of illnesses, which includes bulimia and, perhaps most notoriously, anorexia nervosa.

Anorexia reportedly has the highest mortality rate of any mental illness – impacting people of every gender identity, race, and socioeconomic status.

And yet, a new study has offered hope that it could soon be cured.

Researchers at Canada’s McGill University have found that the condition may be linked to the “blunted” release of a specific chemical in the brain.

They studied male mice which had been engineered to host a rare genetic variant found in many sufferers of eating disorders and substance use disorders.

These mice were found to be deficient in a neurotransmitter, called acetylcholine, which is involved in learned behaviours, cravings, and reward, as Science Alertnotes.

This groundbreaking work "identifies a mechanism and a potential treatment to alleviate these severe psychiatric disorders," the McGill researchers, led by neuroscientists Mathieu Favier, wrote in a paper about their findings, which has been published in the journal Nature Communications.

They suggested that restoring acetylcholine levels could substantially help people struggling with anorexia, and this could be done using a drug already approved for the treatment of Alzheimer's disease.

An estimated 9 per cent of the US population, or 28.8 million Americans, will have an eating disorder in their lifetime(iStock)

Favier and his colleagues confirmed the link between the genetic mutation and substance use disorders in a cohort of patients, some of whom also had eating disorders.

They noted that these two forms of mental illness share some key characteristics, namely that they involve habits that are hard to break and compulsive behaviours – driven by restriction in the case of eating disorders, and by “rewards”, in substance abusers, since addictive drugs activate the brain's reward system, delivering a kick of dopamine and other “happy” compounds in the brain.

The team treated the genetically engineered mice with donepezil – an Alzheimer's drug that inhibits the enzyme that breaks down acetylcholine – and noticed some significant effects.

The animals reportedly began eating normally and fewer dropped weight after previously showing behaviours reminiscent of restrictive eating or bingeing.

"We found that it fully reversed the anorexia-like behaviour in mice, and we believe that it could potentially offer the first mechanism-based treatment of anorexia nervosa," confirmed fellow McGill neuroscientist Salah El Mestikawy, a senior author of the study.

"In fact, we are already seeing its effects on some patients with the disease."

Donepezil is already licenced for the treatment of dementia (iStock)

Ten patients have now been treated with low doses of donepezil as part of a Canadian pilot study, and randomised controlled trials, to test whether the treatment is more effective than a placebo at tackling anorexia nervosa symptoms, are also being planned.

But until these trials are completed, it is unclear how well the results of the animal study will translate into humans.

In other words, we won’t know whether or not restoring acetylcholine levels is an effective treatment strategy, however promising the McGill researchers’ findings may be.

It is also worth noting that Donepezil has some serious side effects, which is why the clinical trials are only testing low doses of the drug.

It is also important to stress that a number of factors underpin disorders like anorexia, both biological and psychological.

In 2019, scientists identified eight genetic markers associated with anorexia after analysing DNA samples from almost 17,000 patients with the illness and around 55,000 people without, Science Alert reports.

As the site notes, identifying these biological underpinnings can help to reduce the stigma associated with mental health conditions, “proving” that they are legitimate illnesses to which people may have a genetic or biological predisposition.

However, these conclusions must always be weighed up against psychological and environmental factors that can also contribute to the onset of certain disorders.

Ultimately, using acetylcholine inhibitors to treat anorexia nervosa and other obsessive-compulsive disorders may be steeped in controversy, and we should emphasise that no medication is a fix-all.

However, the use of appropriate medication, particularly when combined with relevant behavioural therapies, can prove very effective.

We can now just hope that new, successful treatments will continue to be found for some of our most complex issues and disorders.

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