Why Autism Diagnoses Are Often Delayed
How ADHD and sensory processing issues can prevent early intervention
Clinical Experts: Wendy Nash, MD , Catherine Lord, PhD
What You'll Learn
- Why do doctors often miss autism in early screenings?
- Why is it important for autistic kids to get the right diagnosis early on?
- What can parents do to make sure young kids get the right diagnosis?
For kids with autism, getting social skills training as a toddler can make a big difference. But often, children with autism don’t get diagnosed until after they’ve started school. Sometimes, that’s because they get diagnosed with ADHD or sensory processing issues first. These other diagnoses are often correct, but in order to get the right treatment, kids need an autism diagnosis too.
There are a number of reasons why early screenings don’t always catch autism. Doctors often hesitate to diagnose autism if it might be something else. They want to see how the child’s development goes first. Sometimes, kids who have both ADHD and autism just get diagnosed with severe ADHD. Then, nobody realizes there’s more happening until the child starts school and the social parts of autism become clearer.
Autism is also harder to diagnose than ADHD or sensory issues if you’re just seeing your child’s regular doctor. The assessment for autism takes half an hour plus a long interview with parents. So you won’t see it in a standard check-up. Autism also has a range of symptoms that look different in different kids. If your child’s doctor isn’t a specialist, they might not realize your child is showing signs of autism.
If you’ve got a young child you think might have autism, it’s best to take them to a mental health specialist with training and experience with autism in kids. You can also ask for a second opinion if you think your doctor is missing something. Early diagnosis is very helpful for kids with autism, so it’s best to be proactive instead of waiting to see how they develop.
For children on the autism spectrum, very early social skills training, preferably before school age, can have a major impact on later development. But a lot of kids are missing that crucial intervention.
For many, it’s not because they’re not getting diagnosed—it’s because they’re getting a different diagnosis first. Often, it’s ADHD, diagnosed by a pediatrician at age 2 or 3. Or parents are told that their child has sensory processing issues. Then, the autism isn’t picked up until the demands of school and social situations increase. One mother we know got both—sensory processing at 2 years old and ADHD at 4—before her son was diagnosed with autism just shy of his fifth birthday.
Those initial evaluations assessments are not necessarily inaccurate, as far as they go. It is estimated that 30 to 40 percent of children with an autism spectrum disorder do also have ADHD, and sensory processing challenges are so common in kids with autism, they are considered a symptom of the disorder. But they can delay an autism diagnosis if practitioners and parents stop there. And while these children are getting treatment for ADHD or sensory processing issues, they’re missing out on therapy that can have a much more important impact on their lives.
“Starting services early is too important to let a lack of a confirmed diagnosis get in the way,” according to Wendy Nash, MD, a child and adolescent psychiatrist who has treated many children on the spectrum.
Seeing beyond the quick diagnosis
“There is a tendency that once a patient has a diagnosis, because they have a number of symptoms that fit that diagnosis, clinicians can develop a bit of tunnel vision where some other findings might be overlooked,” says Amir Miodovnik, MD, a developmental pediatrician at Boston Children’s Hospital.
Dr. Miodovnik is the lead researcher on a study of autistic children, published in Pediatrics, which linked an initial diagnosis of ADHD to a delay of three years, on average, in the autism diagnosis. Children who had first been diagnosed with ADHD were nearly 30 times more likely to receive their autism diagnosis after age 6 than those for whom autism was their first diagnosis.
The study confirmed Dr. Miodovnik’s clinical experience. “We see a fair number of children we evaluate for autism spectrum disorder at an older age,” he says, “who previously have had an ADHD diagnosis.”
Catherine Lord, PhD, the veteran clinician-researcher in autism spectrum disorders now a professor and researcher at UCLA, has a similar concern that an early focus on sensory issues, while it may help kids some, may be delaying autism diagnoses. “We see kids who fall on the autism spectrum,” she reports, “and for years they’ve been going to speech and language therapy and occupational therapy for sensory issues, when they should have had people working with them on social skills.”
Why is autism overlooked in these early screenings?
There are a number of reasons why these initial autism evaluations don’t result in an autism diagnosis, explains Dr. Nash. To avoid delays, parents should be aware of them.
- Both clinicians and parents gravitate toward the diagnosis with the best prognosis. “Understandably, clinicians want a certain level of certainty before delivering a lifelong diagnosis of potential impairments,” she says. “So the initial approach is often to treat what’s treatable and then reassess. For example, ‘Let’s treat this as ADHD first and see how much of the poor eye contact is related to inattention.’ “
- Pediatricians want to give development a chance. It makes sense with children, since they do develop at different rates, says Dr. Nash. But doctors have a tendency to want to reassure parents, whose observations and worries are often discounted.
- Autism can’t be diagnosed in a quick office visit. One reason pediatricians may not pick up autism, Dr. Nash observes, is because the evaluation takes too long. The standard assessment tool, called the ADOS—the Autism Diagnostic Observation Schedule—takes 30 minutes. And it’s meant to be paired with a structured interview with parents about current and past symptoms, and that takes several hours.
- ADHD paired with autism can look like severe ADHD. “I hear the description ‘severe ADHD’ a lot, and, in my experience, it often turns out to be autism,” Dr. Nash explains. “If you put the two impairments together—the impulsiveness and the perseverative mindset—these kids can really get stuck in a loop, and they cannot get off, and that can be very disruptive.”
- Autism is a spectrum, with a wide range of behaviors. A non-specialist might not recognize its symptoms because they’re more varied and nuanced than he realizes. For example, a clinician might say a child had eye contact, or he was smiling, so he can’t be on the spectrum. But what characterizes autism, Dr. Nash notes, is how that eye contact is used in social interaction. “Kids with autism have a narrow range of affect. But sometimes the affect is a persistent smile. A child might be staring and smiling.” At that same time, what the clinician observes is just one moment in time; he may not see behaviors parents are picking up at home.
- Sensory issues are often picked up in preschools. Many of them have occupational therapists on staff, who are available to work with these children. Sensory problems may indeed be causing a child distress, but they are often not the whole picture, Dr. Nash notes. “When sensory processing becomes the primary or sole focus, the child loses out, loses valuable time.”
Dr. Nash urges parents of young children who suspect that they may be on the autism spectrum to make sure they get a full assessment by a professional who is trained and experienced in diagnosing the disorder—a pediatric psychiatrist, neurologist, or developmental pediatrician.
And if as parents you feel the diagnosis is still incorrect or inadequate to explain the behavior you see, you may want to seek out another opinion. It can be tempting to accept the efforts of friends, family, and even clinicians to avoid a label that can be scary, but a wait-and-see approach is not a good idea if autism is a possibility.
“Empower yourselves as parents,” Dr. Nash urges. “Advocate for your child.”