New research seems to show encouraging progress in helping treat the complex neurodevelopmental disorder autism. Two unrelated clinical trials, involving men and children with autism, suggest that using drugs to interact with a hormone called vasopressin could improve the social functioning of people living with the disorder, though one approach may be better than the other.
Vasopressin is used by the body to maintain kidney function and regulate the blood pressure of our arteries, and it’s already used medically for some kinds of circulation problems. But animal studies, primarily in rodents called voles, have shown that vasopressin in the brain also seems crucial to these animals’ healthy social behaviours, including bonding with their mates. In humans, research has also started to show that giving vasopressin to both healthy people and those with cognitive issues like dementia can improve memory and social skills like cooperation.
Karen Parker, a psychiatrist and behavioural scientist at Stanford University, was keenly aware of the research into voles’ social lives, having studied them in her early career. But she’s since expanded on that work as director of the university’s Social Neurosciences Research Program.
She and her team have found evidence that children living with autism spectrum disorder (ASD), as it’s formally known, have less vasopressin circulating in their spinal fluid than children without ASD. They also found that children with ASD with the lowest levels of vasopressin had the most severe symptoms, which can include speech and language difficulties, hypersensitive senses, and poor cognition and IQ.
Building on all of this, Parker and her team decided to conduct a double-blinded, randomised, and controlled trial of 30 children with ASD between the ages of 6 and 12. Over a period of four weeks, they either gave their subjects a nasal spray containing a form of vasopressin or a placebo.
Compared to those who received the placebo, they found that, on average, children with ASD given vasopressin had noticeably improved social skills, with little to no apparent side effects. These improvements included better social communication, more accurate recognition of people’s facial emotions, and a better “theory of mind,” or the concept of being able to guess what others are feeling or thinking. The results were not only based on surveys completed by their parents (the trial’s primary outcome), but also examinations by a doctor and tests of social cognition.
“This is a pilot trial, so it’s important to acknowledge that,” Parker told Gizmodo. “But there were significant improvements in kids on vasopressin. And we saw this convergent evidence on parent ratings, clinician evaluations, and laboratory tests of children’s performance.”
Parker added that this same sort of trial needs to be done with much larger groups of people and preferably by more than one research team before any of their results should be seen as concrete. Another consideration is that boys are diagnosed with ASD at much greater rates than girls, and though there’s some evidence that vasopressin’s social effects on ASD shouldn’t be gender-specific, her trial alone can’t tell us whether that’s really the case, given the small number of girls (5 in total) studied.
Meanwhile, another double-blinded, randomised, and controlled trial conducted by scientists from Roche — the Swiss-based pharmaceutical — found interesting but less clear results from their attempts to use drug treatment to improve the social functioning of adults with ASD. They gave 223 men with ASD either a placebo or varying doses of an experimental drug designed to block one type of cell receptor in the brain that links up to vasopressin, for 12 weeks.
Unlike Parker’s study, Roche’s trial did not meet its primary goal, meaning that men with ASD did not socially improve any more than those on placebo, based on a survey filled out by their caregivers. But there were some improvements seen with communication and socialisation in men who had gotten the second-highest and highest doses of the experimental drug, based on another questionnaire that clinicians give to the person directly.
Both trials were published in Science Translational Medicine on Wednesday.
As noted by both teams (who did not coordinate beforehand, according to Parker) in their papers, their approaches to interacting with vasopressin in the brains of people with ASD are basically the opposite of one another. But while Roche’s results should probably be treated with even more guarded scepticism than Parker’s, we know that ASD is a complex disorder with no clear causes or biological roots underlying the disease. So it’s still possible that blocking vasopressin may help some people with a certain kind of autism, while boosting vasopressin may help others.
In any case, these trials bring us closer to something we just don’t have right now—a medication that can directly treat and manage the core symptoms of ASD. Currently, behavioural interventions can help people with ASD better navigate the world socially, especially the earlier they begin therapy. But the only FDA-approved drugs for ASD are antipsychotics that are supposed to tamp down the irritability that people with the disorder often feel.
Parker and her team are already planning a larger trial of the vasopressin nasal spray in children with ASD, she said, and earlier work by her team has also pointed to low levels of oxytocin as a potential therapeutic target for some with ASD. She also hopes to start testing in monkeys the theory that giving vasopressin to high-risk children early in life could not only reduce their eventual symptoms of ASD but possibly even prevent it. Roche is also conducting its own trial of the same experimental drug in children between the ages of 5 and 17.
Discussing potential treatments for ASD does come with its own set of ethical issues, though. Many people in the autism community have started to speak out against the framing of ASD as an inherently harmful condition that needs to be cured or prevented; some also argue that more focus should be put on destigmatizing ASD rather than finding a treatment. Parker said she’s sensitive to these arguments, though she feels obligated to do what she can for those who walk into her office.
“I very much respect that movement,” she said. “What I will say is that parents and kids can come into the clinic and say they’re suffering. And we as clinicians are duty-bound to help them diminish that suffering.”