Specially trained service dogs may reduce stress in children with autism, according to a new study.
The results showed children with an autism spectrum disorder experienced a decrease in levels of the stress hormone cortisol after a service dog was introduced into the family. Autism spectrum disorders (ASDs) are a range of conditions in which kids have trouble communicating and interacting with others, and behave appropriately in social situations.
Previous research has shown these dogs can help autistic children in social situations and improve their daily routine. But the new study is the first to show the furry friends can have physiological benefits as well.
"Our findings showed that the dogs had a clear impact on the children's stress hormone levels," study researcher Sonia Lupien, a professor at the University of Montréal, said in a statement. "I have not seen such a dramatic effect before."
The dogs also improved the children's behavior, reducing the number of problems reported by parents.
The findings are published in the September issue of the journal Psychoneuroendocrinology.
Bringing in four-legged friends
Lupien and her colleagues measured the cortisol levels in the saliva of 42 children with an ASD. Normally, production of cortisol reaches peaks about 30 minutes after a person wakes up, a phenomenon known as the cortisol awakening response, and it decreases over the course of the day.
The children's cortisol awakening response was measured before, during and after the service dog was introduced. The dogs were specially trained to be obedient and remain calm even in chaotic environments.
In the two weeks before the dogs were brought in, the children's cortisol levels rose 58 percent during the first 30 minutes they were awake in the morning. But when the dogs were present, this awakening response was reduced to just a 10 percent rise. And when the dogs were taken away after four weeks, the cortisol awakening response jumped back up to a 48 percent increase.
Parents also reported a decrease in their child's problematic and disruptive behaviors, such as tantrums, when the dog was there. The average number of these behaviors dropped from 33, in the two weeks prior to the dog's presence, to 25 while the animal was part of the household.
The researchers noted that few studies have looked at cortisol levels in children, so the effect of the reduced cortisol on the child cannot yet be determined. However, studies in adults have linked increases in the hormone to increases in general stress, and decreases in the hormone to a positive mental state.
More research needs to be done on autistic children to figure out if these decreases in cortisol levels actually correspond to a change in a child's stress level, the researchers say. Earlier studies have found that autistic children are calmer and happier when a service dog is around, the researchers said.
Future studies should also examine why the dogs decrease cortisol levels. For instance, it could be that the dogs help children sleep better, which may have affected the cortisol levels, the researchers said.
"Introducing service dogs to children with ASD has received growing attention in recent decades," Lupien said. "Our results lend support to the potential behavioral benefits of service dogs for autistic children."
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