A Simple Smell Test Can Detect Autism In Children

Benjamin Simon

Detecting autism in young children can be difficult, since many of the indicators of autism are not obvious during behavioral development. But scientists recently discovered a non-verbal smell test that can accurately detect whether the participant is on the autism spectrum.

According to Science 20, the smell test works by determining which participants can tell the difference between a repulsive smell and a pleasant one. Humans naturally breathe in deeper when we smell something we like, such as flowers or chocolate. But when an unpleasant odor comes along, people tend to breathe in less--or even hold their breath. But this subconscious response is not triggered by people with autism. Previous research revealed that those with autism have a slight impairment in the brain that inhibits their "internal action models," which affect the brain's response to sensory stimuli.

According to Science News, the study was led by Noam Sobel from the Weizmann Institute of Science in Israel, along with Liron Rozenkrantz and a team of colleagues. Their research reveals that this autism impairment is significant enough to be recorded and reliable enough to confirm autism in young children.

The team ran the smell test with 18 children on the autism spectrum and 18 children who had developed normally. Using specially-made pediatric nasal cannulas, Sobel and his team fed both pleasant and unpleasant scents through the tubes and detected the sniff reaction of children with and without autism. Normally, developing children would react to the smell within 305 milliseconds, but children with autism did not react at all.

"The difference in sniffing pattern between the typically developing children and children with autism was simply overwhelming," Sobel said. "We can identify autism and its severity with meaningful accuracy within less than 10 minutes using a test that is completely non-verbal and entails no task to follow. This raises the hope that these findings could form the base for development of a diagnostic tool that can be applied very early on, such as in toddlers only a few months old. Such early diagnosis would allow for more effective intervention."

While the smell test may seem like a flawlessly effective way to detect autism, Sobel and his team claim it's not ready for clinical use yet. The team could accurately identify autism within young children 81 percent of the time, which is a significant figure, but not without a margin of error. Severe autism can also result in extremely unusual smelling habits due to the social impairments the child experiences rather than the chemistry of the brain.

Noam Sobel recently found out another fascinating about the sense of smell, determining that every individual's sense of smell is so unique that scientists can identify specific people simply by how they describe certain odors.

For more on autism, read about how autism might be linked to the age of the parents--but not necessarily as a cause of autism.

[Image credit: Sobel and Getty]