Smell Test Helps Detect Autism

Researchers at the Weizmann Institute of Science in Israel led the study which examined the link between olfaction and autism spectrum disorder (ASD). A simple test could detect autism but maybe the sniffing one is simply not enough. Miss Rozenkrantz, member of the research team, added: “But before we can use it as a diagnostic test, we need to know at what age children start to develop a sniff response in the general population”.

In a trial, 17 boys and a girl with ASD and the same number of children who were developing normally were presented with nice smells and bad smells in a laboratory through special tubes under their noses.

What the scientists could not determine is whether the autistic children didn’t perceive the odors when other children did, or they had a problem with their sniffing instinct and behavior.

The researchers found that while children without autism adjusted their sniffing within 305 milliseconds of smelling an odour, the autistic children did not adjust their sniffing.

This drawing shows how children in the study were seated in front of a computer monitor while viewing a cartoon, with nasal airflow measured and pleasant and unpleasant odorants delivered via a nasal cannula and olfactometer. The average age of children in the study was seven years. However, autistic children did not alter the way they breathe in response to the various smells.

The team notes that past studies have suggested individuals with autism have impairments in areas of the brain responsible for sensory and motor coordination – known as “internal action models”, or IAMs. Children with more severe symptoms, especially for impairments in social communication, actually seem to inhale unpleasant smells longer than pleasant ones.

If the findings are substantiated by further research, the technique could help to diagnose children sooner.

Dr. Andrew Adesman, chief of developmental and behavioral pediatrics at Cohen Children’s Medical Center of New York in New Hyde Park, N.Y., remarked, “This study is in many ways provocative, since it suggests, in children with an autism spectrum disorder, that there may be a previously unappreciated relationship between their response to smells and their impaired social functioning”.

The researchers plan on testing whether the sniff-response pattern they’ve observed is specific to autism or if it also shows up people with other neurodevelopmental disorders.