Oxytocin – the "cuddle hormone" – may hold promise as a treatment for anorexia nervosa, according to two studies by a British-South Korean research team.
Oxytocin is a naturally occurring hormone released during sex, childbirth, breastfeeding and emotional bonding. Synthetic oxytocin, delivered via nasal spray, is being tested in patients with a variety of psychiatric disorders, including autism and anorexia.
In a study published Wednesday in the journal Psychoneuroendocrinology, anorexic patients given a dose of oxytocin via nasal spray became less fixated on images of high calorie foods and larger body shapes.
An earlier study by the same team found that anorexic patients given oxytocin were more able to face images of anger – and less likely to fixate on images of disgust.
The authors noted that patients with anorexia nervosa may have difficulty dealing with anger, perceiving it as "toxic" and unacceptable, "which may lead to anger suppression," they wrote. Conversely, anorexic patients tend to be oversensitive to images of disgust.
"Our research shows that oxytocin reduces patients' unconscious tendencies to focus on food, body shape and negative emotions such as disgust," said lead author Youl-Ri Kim, from Inje University in Seoul, in a release.
The findings raise the possibility that oxytocin treatment may moderate some of the social problems associated with anorexia and help reduce obsession with food and body weight, the authors wrote.
The use of synthetic oxytocin made headlines last year when a study from Yale University found that a single dose helped children with autism pick up on social cues.
But the benefits of oxytocin may depend on the patient's psychiatric state, other research suggests.
A 2013 study from Concordia University in Montreal found that healthy young adults given measured doses of oxytocin via nasal spray became oversensitive to emotional cues.
The researchers described hypersensitivity as a negative side effect of synthetic oxytocin.
"If your potential boss grimaces because she's uncomfortable in her chair and you think she's reacting negatively to what you're saying, or if the guy you're talking to at a party smiles to be friendly and you think he's coming on to you, it can lead you to overreact – and that can be a real problem," co-author Christopher Cardoso explained in a release. Will the findings hold true in anorexic patients?
It's a question researchers will need to answer before oxytocin becomes an accepted treatment for the life-threatening eating disorder.
Members of the British-South Korean research team theorize that oxytocin may help reduce the social difficulties and isolation experienced by anorexic patients.
"By using oxytocin as a potential treatment for anorexia, we are focusing on some of these underlying problems we see in patients," said Janet Treasure, a professor at King's College London's Institute of Psychiatry.
But she acknowledged the research is in the early stages. "We need much larger trials, on more diverse populations, before we can start to make a difference [in] how patients are treated," she said.