While receiving the worm treatment, the participants showed a decrease in the repetitive behaviors that are common among people with autism, according to preliminary results from five of the patients that Hollander presented today (Dec. 12) at a meeting of the American College of Neuropsychopharmacology (the other five patients are still doing the trial). However, during the worm treatment, the patients did not show improvement in social or communication skills.
The Food and Drug Administration has not approved the worm treatment for autism. Scientists will need to demonstrate it's effective in larger trials first, Hollander said. "Clearly more work needs to be done, but this offers a new avenue for treatments," he told LiveScience.
Worms aren't the only type of therapy for autism Hollander is exploring. Another theory suggests high levels of stress on the mother during pregnancy can cause autism by leading to a spike in the stress hormone cortisol, which interferes with the development of a specific signaling pathway in the baby's brain. (7 Ways Pregnant Women Affect Their Babies)
Changes in this signaling pathway might explain why about a third of children with autism experience improvement in their symptoms when they have a fever, according to reports from parents.
In another study Hollander presented today, 15 children with autism, some of whom had a history of improvement due to fever and some of whom didn't, soaked in a hot tub at 102 degrees Fahrenheit (38.9 Celsius) or 98 F (37 C) for 30 minutes.
The children who had a history of improvement in their autism symptoms after fever showed some improvement in social skills after spending time in the 102-degree hot tub. Exactly why the heat may help remains unclear, but the temperature might affect certain enzymes that control whether genes are turned on or off in the brain, Hollander said.
Adesman called the study "clever" and "intriguing," but noted that it wasunclear whether children who don't see their autism symptoms improve from fever also benefit from the hot tub therapy.
Elaine Hsiao, a researcher at Caltech who studies autism and immunity said the research "lends support for immune-based therapies for ASD."
Growing research shows that microbes with the human body modulate brain function and behavior, Hsiao said. It will be important for researchers to figure out how the worm treatment leads to beneficial effects on behavior, whether it's through changing the immune system, the digestive tract, or other indirect effects, she told LiveScience.
Hollander also presented a third study today, which involved giving 34 high-functioning adults with autism a drug that blocks reuptake of the brain chemical norepinephrine, which may be activating the same brain circuits as fever does. These adults showed improvements in attention and executive function, Hollander reported, though he called for these findings to be replicated as well.
More from LiveScience:
Beyond Vaccines: 5 Things that Might Really Cause Autism 11 Facts Every Parent Should Know About Their Baby's Brain 5 Controversial Mental Health Treatments Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
This story originally appeared on LiveScience.com.