Based on the latest data by the Centers for Disease Control and Prevention (CDC), approximately 1 in 36 (~2.7%) children in the United States are diagnosed with autism spectrum disorder (ASD).1 Over the last few years, the increase in clinical ASD diagnoses has led some researchers to attribute this rise to mis- and overdiagnoses of the condition,2 and also, to the growing awareness among the general population and scientific community.3
We reached out to clinicians involved in the diagnosis and care of patients with ASD to get further insights on screening for and diagnosing autism in the US and the collaborative efforts that may result in more favorable patient outcomes.
The discussion panel included the following clinicians:
- Pediatric neurologist Ann Neumeyer, MD, medical director of the Massachusetts General Hospital’s Lurie Center for Autism in Lexington and associate professor of neurology at Harvard Medical School in Boston.
- Nora D. Friedman, MD, child, adolescent, and adult psychiatrist at Lurie Center for Autism and instructor at Harvard Medical School.
- Clinical neuropsychologist Suzanne W. Duvall, PhD, ABPP, associate professor of pediatrics and psychiatry, division of psychology, and associate director of clinical training, Clinical Psychology PhD Program, Institute on Development and Disability at Oregon Health & Science University (OHSU).
Ann Neumeyer, MD
Nora D. Friedman, MD
Are Diagnostic Criteria for ASD Misleading?
In 2013, the American Psychiatric Association (APA) developed standardized criteria —according to the Diagnostic and Statistical Manual, Fifth Edition (DSM-5) — to diagnose ASD by combining 4 conditions: autism, Asperger syndrome, childhood disintegrative disorder, and pervasive development disorder not otherwise specified (PDD-NOS).4
However, in a review, neuropsychologist David Rowland wrote that autism is more of a brain anomaly than a developmental disorder and that the National Institutes of Health (NIH)’s list of signs and symptoms may be too vague to confirm autism.5
Following the revision of the criteria that introduced the concept of a “spectrum,” the diagnosis of autism appears to be based on behaviors shared with other diagnoses of uncertain similarities.3,6 The broad definition of autism and overlapping symptoms with complex conditions have created challenging situations in practice, with false diagnoses — both false positives and negatives — affecting autism assessment.5,7
Based on these scenarios, we asked Drs Neumeyer and Friedman about diagnosing autism in clinical practice.
Q: What are some of the typical and atypical signs of autism that you have come across? What are your clinical pearls in identifying these signs and symptoms? How quickly must they be addressed?
Dr Neumeyer: The young children with language delay are often diagnosed early and the children who don’t have language delay often have delayed diagnosis or misdiagnosis. When I think about diagnosing autism, I think about the DSM-5 criteriafor autism4 that the child has to have: social communication delays, delays in social and emotional reciprocity, nonverbal communication, and maintaining relationships. Many children with autism who are considered “intelligent” have impaired relationships; however, unless you ask parents, they don’t tell you that.
With regard to health outcomes, one of the other things that is really important is that autism in many individuals is associated with sensory function, and patients become really picky about the foods that they eat, which can lead to nutritional deficiencies. Some patients with these nutritional deficiencies have poor bone growth and density, which can lead to osteoporosis.
Dr Friedman: ASD can be defined as deficits in social communication and interaction, as well as restricted and repetitive behaviors. We want to understand how these issues manifest across settings. As part of the diagnostic work-up, it is important to assess for co-occurring conditions, such as anxiety or attention-deficit/hyperactivity disorder (ADHD). We try to think holistically about the individual with ASD, talking with families about therapeutic and behavioral interventions, school and employment supports, and medication management if indicated. In addition, we aim to connect patients with services as quickly as we can.
Diagnosing Autism in Adulthood
Age at ASD diagnosis is directly related to achieving optimal outcomes, which may be improvements in cognition and language or adaptive behavior, as well as reduced costs for families, society, and the health care system as a whole.8 In recent years, studies have shown an increase in autism assessments among adults, including diagnoses in both adulthood and after the childhood-to-adulthood transition.9
In a 2023 study published in the International Journal of Mental Health Systems,8 the lived experience of patients with an ASD diagnosis in adulthood was noted. Some of the common themes in their ASD diagnostic journeys were observing differences and similarities between themselves and patients with ASD; barriers in diagnosis, such as cost of care and wait times; and emotional health.
Drs Neumeyer and Duvall presented fairly similar views on why autism diagnoses happen later in life, and the outcomes associated with them.
Q: Data from studies have indicated an increase in autism being diagnosed in adulthood, which can lead to poor health outcomes.8 Can you explain the reasons for these diagnostic delays, and how providers can address this?
Dr Neumeyer: Adults who are being diagnosed with autism are typically considered “intelligent” and who have been able to mask their symptoms or that their condition was misdiagnosed, for example, with anxiety, ADHD, or learning disabilities. There is a smaller group of older adults who are not diagnosed early because when they were younger, autism was just defined as very severe repetitive behaviors and lack of language skills.
Dr Duvall: The most common scenario is that individuals with more nuanced symptoms of autism can be missed in childhood and then go on to receive a diagnosis in adulthood, but in retrospect, the same behavior patterns or social communication [delays] were always present. Autism has a genetic component, thus sometimes, when we provide an ASD diagnosis to a child, the parent notes that they were “just like them” when they were a child and may go on to seek evaluation for an ASD diagnosis themselves.
Gaps and Barriers in Autism Evaluation
To identify barriers in receiving autism diagnosis, researchers at Stanford University, California, conducted a study that revealed sparse and uneven distribution of diagnostic resources in the US, which resulted in increased waitlists and travel distance. Specifically, patients from rural communities were less likely to be diagnosed than those from urban communities who lived closer to diagnostic centers, indicating a gap in access to care.10
In addition to this, the important role of pediatric primary care providers — the first point of care during early childhood — in helping access autism services has also been noted in a 2022 study published in Autism Research.11
Dr Neumeyer spoke further about the existence of barriers in the diagnosis of ASD.
Q: In the US, several clinical specialties are facing a shortage of pediatricians due to certain factors — increasing demand, lesser students opting for pediatrics as their specialty, and poor financial incentives — resulting in gaps in access to autism resources.10 Can you describe some of the most common barriers in achieving a timely and accurate autism diagnosis?
Dr Neumeyer: The number of individuals opting for the subspecialty of developmental behavioral pediatrics is very low, with many fellowships not being able to fill their slots.One of the results of that isthat it is the specialty that diagnoses and cares for children with neurodevelopmental disabilitiesand autism. So, we are in desperate need of more developmental behavioral pediatricians.
Every state in the US has different rules according to which it is decided who diagnoses autism; in Massachusetts, any MD or psychologist can make a diagnosis. One of the barriers in Massachusetts is that most pediatricians don’t feel comfortable or have the training to make a diagnosis. The way their practices are run, it is very difficult to make an autism diagnosis because they see patients quickly, and diagnoses require more time spent with patients. So, typically, psychologists, pediatric neurologists, and psychiatrists make a diagnosis in Massachusetts.
The other, more research-based, challenge is the lack of a biomarker for autism, so we can’t diagnose just with a test. There are some online companies that have been good at getting a validated diagnosis for autism, but those are new.
What’s Needed for Autism Diagnosis? Role of Collaboration Between Specialists
Experts agree that a multidisciplinary team of health care professionals and awareness of “red flags” by parents, families, and teachers can be an optimal diagnostic approach.8
Q: What is the role of each neurologist, psychiatrist, and psychologist in diagnosing autism? In addition, what collaborative efforts must be taken by the specialties to screen for and diagnose autism, and how should providers go about referrals for autism?
Dr Neumeyer: Generally, here, we start with a psychologist for evaluation of autism and the neurologist and psychiatrist work hand-in-hand, especially when there are atypical features or physical findings. It is very important to bring in the neurologist to make sure there’s no genetic involvement or other syndrome causing or associated with the autism. The psychiatrist can be very important when there are behavioral difficulties. The reality is that there are not enough child psychiatrists in the US, and so, many pediatric neurologists and pediatricians also treat the behavioral aspect of children with autism.
Dr Friedman: Ideally, patients undergo a multipronged evaluation. This can include [evaluation of] history, a clinical interview, observation, physical exam and work-up, and cognitive and/or developmental testing. Understanding a patient’s unique profile informs treatment planning. The available resources in a given area will, in part, dictate the specific clinicians whom a family sees, the subsequent referrals that are made, and access to services. Collaboration among team members is essential for optimal care for patients and their families.
Dr Duvall: In our interdisciplinary ASD-specific assessment clinic, 100% of the individuals coming in report that social difficulties are, at least, part of why they presented with this diagnostic question. However, only about 30% to 50% of the older children and teens who present for a comprehensive ASD assessment receive an ASD diagnosis, while rates in children younger than age 4 may be closer to 60% to 80%.
There is high variability across primary care providers and pediatricians around expertise in neurodevelopmental disorders. If caregivers are concerned, they should talk with their primary care provider to complete in office screening, such as questionnaires or behavioral observation, and then ask for a referral to a specialist for evaluation, as early interventions are often the most effective in supporting skill development.
