Every kid has their quirks. They cut the tags out of their shirts, loathe the texture of bananas, or avoid fluorescent lights. But for some kids, sensory stimuli can be so overwhelming it impairs daily function. They can’t focus at school and meltdown in the supermarket. The itch of a T-shirt tag ruins their whole day. That’s what it’s like to have sensory processing disorder, or SPD — a controversial condition characterized by difficulty processing sensory information, including sound, touch, and taste.
Some people with SPD are quick to overload; what may sound to a neurotypical person like an innocuous ticking of the clock can cause in neurodivergent kids physical symptoms such as headaches, nausea, and vomiting, as well as severe emotional distress. But others may not respond to such stimuli at all: SPD also includes people who are under-responsive to environmental stimuli, those who only the loudest music or brightest colors seem to reach.
But an SPD diagnosis remains contentious. The most recent edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), which the American Psychiatric Association published in 2013, did not include SPD. Those familiar with the situation say that although the APA considered the condition, it ultimately concluded there wasn’t enough evidence at that time to support SPD as a standalone disorder.
The issue isn’t whether sensory processing problems exist (they do), but whether they’re a symptom of other disorders or a disorder in their own right. That’s because SPD is most commonly seen in children with autism, almost all of whom have some sensory processing problems. Sensory processing issues are also associated with attention-deficit/hyperactivity disorder (ADHD), anxiety disorders, and developmental coordination disorders. “It cuts across every diagnosis,” says Lindsey Biel, an occupational therapist and author of Raising a Sensory Smart Child.
Biel also believes SPD can and does appear on its own — something many healthcare providers don’t agree with. “Because there is no universally accepted framework for diagnosis, sensory processing disorder generally should not be diagnosed,” the American Academy of Pediatrics wrote in 2012 in its official statement on SPD.
This foundational disagreement makes sensory-based interventions tendentious, too. In its same policy, the AAP warned that research on sensory integration therapy, which can include activities such as wearing weighted vests or desensitizing patients to senses with brushes or balls, was “limited and inconclusive.” Although “occupational therapy with the use of sensory-based therapies may be acceptable as one of the components of a comprehensive treatment plan,” it urged caution among patients and providers. (The AAP told Fatherly it has plans to review its policy.)
“Right now there is a tendency for everyone to think everything is sensory because it’s a lot more comfortable to think, ‘Oh, it’s a sensory issue!’ and not ‘My child is behaving badly,’” Biel says. But new research is helping to define what SPD is — and isn’t — and what might be done to help kids and families struggling with the condition.
Alison Lane, Ph.D., an occupational therapist and professor at the University of Newcastle, Australia, where she studies sensory features of autism, says that some strategies, such as environmental modification and qi gong massage, show promise in autistic children. Others, such as weighted vests, have no substantive evidence to support them.
Even so, much of the existing science has serious limitations. Sensory interventions are currently based on small trials conducted primarily in autistic children, which could create a bias in understanding of the condition. The research hasn’t been nuanced, either. Study authors have tended to lump all sensory stimuli and purported solutions together, instead of evaluating them one by one. And many interventions lack a theoretical basis to explain how they might actually work in the mind and body to create change.
This is frustrating for parents who are dealing with a child’s sensory processing issues today. Without a formal categorization in the DSM-5, paying for treatment can be difficult. “Insurance is not going to cover it,” Biel says. Occupational therapists can often find a workaround, billing, for example, for the “functional deficits” children with SPD experience. But reimbursement limbo can still be a blow to families.
It’s hard in other ways, too. “These are really difficult problems that cause a lot of stress in family units,” Lane says. When kids routinely have meltdowns from seemingly innocuous stimuli, parents and siblings are affected by the fallout. As a result, Lane says, “they’re very susceptible to misinformation,” making more robust research all the more important.
If scientists like Lane can orchestrate bigger and better studies, they may soon be able to parse what interventions will reliably work for which patients and when — and reduce the confusion and false starts so many families experience when seeking treatment. Lane suspects the end result will be a personalized medicine approach that efficiently and effectively combines sensory, behavioral, and psychological interventions.
“Everybody wants to know, is my child going to get better? Can you fix this?” Biel says. “I can say, kids do get better, and they learn how to tolerate things.”