
Jessica M. Davis, M.D., is often the first stop for parents of children under 5 who are suspected of having autism spectrum disorder. Deciding which kids to recommend for further assessment is a complex task. Autism is difficult to diagnose in anyone, and even more so in the very young.
“I’m looking for decreased eye contact,” she explains of her assessment checklist. “Speech delays, lack of nonverbal communication — gesturing — poor or decreased social interactions, repetitive body movements, repetitive play, or repetitive speech.”
While traits of autism tend to vary between boys and girls who are older, Dr. Davis sees no separation of traits in girls and boys in the under-5 age group.
“The red flag symptoms at this time for girls versus boys are not different,” she explains. “Also, there is not a way to differentiate symptoms based on gender per the existing criteria to diagnose autism, so I ask the same questions for both girls and boys.”
How is autism diagnosed?
Autism is a lifelong, neurodevelopmental disorder defined by cognitive differences and social difficulties. The cause of autism remains unclear, though a genetic component is increasingly suspected.
No two autism diagnoses appear in the same way, and the difficulty of making a diagnosis varies from person to person. That’s part of why the condition is famously hard to diagnose and involves a lengthy assessment process.
At Mayo Clinic, this process can be long. After an initial assessment, a multidisciplinary team of psychologists, social workers, pediatricians and psychiatrists work with combinations of assessment benchmarks to arrive at a diagnosis of autism spectrum disorder (ASD). Efforts are being made to streamline this process for children and families so an accurate diagnosis can be reached without such an extensive evaluation.
Teams are looking for early symptoms of autism such as:
- Speech and language developmental delays.
- Sensory difficulties, such as sensitivities to food textures, labels on clothes, bright lights, and loud, sudden sounds such as a motorcycle roaring past, a siren or the clank of cutlery dropped on a plate at a family gathering.
- Physical developmental delays, such as taking longer than peers to crawl or walk.
- Challenges with social interactions, including social cues, norms and etiquette, and finding it hard to connect with peers.
- Repetitive physical movements, such as flapping arms or hands, known as stimming.
- Disruptive behavior inappropriate to the social or educational setting.
- Highly focused special interests — for example, becoming obsessed with a Disney movie, helicopters or dinosaurs.
- Emotion dysregulation, such as a strong reaction to a peer taking a beloved toy.
- Highly ritualized daily routines, such as insisting on taking the same route to school or a bedtime checklist of wind-down rituals that must be followed by parents or the child cannot go to sleep.
- Fussy or restrictive eating.
- Low levels of eye contact.
- Nonverbal phases, known as selective mutism (as happened in Greta Thunberg’s childhood) can occur, triggered by changes in the family’s dynamic or circumstances.
- Fits of emotional overreaction or anger, known as autistic meltdowns, which may involve crying, shaking, screaming, hitting oneself and banging one’s head against a wall.
If a diagnosis is agreed on, the child’s autism is matched to the gradients of a broad autism spectrum, set out in the Diagnostic and Statistical Manual of Mental Disorders (DSM)-V in 2013. At one end of the spectrum are kids who are nonverbal, with intellectual and social impairments. This is often called low-functioning autism. At the other end of the spectrum are the autistic savants — think Elon Musk or the character Sean Murphy in the hit medical drama “The Good Doctor.” This is often called high-functioning autism. In between are individuals whose midrange traits and symptoms are still diagnosed as autism but may only be noticeable to those close to them.
Benefits of early diagnosis
In the 1980s, autism was diagnosed at a global rate of 6 per 10,000 people. Today that rate is 1 per 100 people. New Centers for Disease Control and Prevention research states that 1 in 44 American children has been diagnosed with ASD and this ranges across all racial, ethnic and socioeconomic groups.
Dr. Davis attributes the recent increase in assessment and diagnosis to improved assessment networks, a wider understanding of autism and the availability of more-concrete information. She doesn’t see it as a trend toward overdiagnosing. Increased rates of diagnosis also are unrelated to persistent myths about false autism causes such as vaccines, diet and so-called refrigerator mothers with cold and uncaring parenting styles.
In fact, Dr. Davis’ goal is always early autism diagnosis, to head off unnecessary challenges for kids who may reach adolescence undiagnosed with exponential associated risks, notably a sevenfold increased suicide risk as reported by the British Journal of Psychiatry. Backing up this risk, researchers at University of Virginia found that many female and gender-diverse adolescents whose autism has been overlooked are at greater risk of developing mental health conditions such as depression, eating disorders and anxiety — and of developing behaviors such as self-harm.
“This is why we are always trying to get the diagnosis at an earlier age,” says Dr. Davis. “I work with children with speech and language delays from 9 months to 5 years old. So that’s the population in which I’m trying to figure out whether children have autism. What happens is I triage children and if they meet criteria for an autism assessment, which is usually on average 1 in 2 kids that I triage, then I will send them to our bigger developmental team for a full assessment. Our goal is to try and get kids diagnosed before the age of 3 or closer to 2, as therapies can be more effective from that age on.”
How is autism treated in children under 5?
- Speech and language therapy.
- Occupational therapy.
- Physical therapy.
- Nutritional therapy.
- Applied behavior analysis.
- Sensory integration therapy.
- Developmental, individual-differences, relationship-based approach (DIR).
- Support groups and positive home-school collaboration.
What can parents do to help a child under 5 diagnosed with autism?
- Buy a weighted blanket for the child to wrap up in during a meltdown or period of stress.
- Keep routines as strict and familiar as possible, as autistic children thrive on familiarity and have difficulty during change.
- Maintain an honest dialogue with teachers and caretakers.
- Create a code word with the child when being overwhelmed in a social setting or in public — for example, banana — so it’s easier to help the child step away from challenging scenarios.
- Decorate the child’s bedroom with neutral colors and soft lighting to promote calmness.
- Set aside extra time to help the child understand what is learned at kindergarten.
- Be patient with special interests even if it means sitting through another video about dogs or space travel.
- Cut tags off all your child’s new clothes and make sure fabrics are not itchy or scratchy, as this can trigger sensory agitation.
- Cook your child’s favorite meals as often as possible and avoid experimentation in the kitchen.
- Understand that autism can make physical touch such as hand-holding and hugs feel claustrophobic — learn to ask questions such as, “May I give you a hug?”
- Get educated on autism and look for parent support groups online or in your area, as raising an autistic child has been proved to put a significant strain on families.
Does autism run in families?
If families have one child diagnosed with ASD, they understandably want to know if siblings or a future child may be at risk of having ASD. A 2017 study by Harvard Medical School projected the risk of a second child in the same family being diagnosed with ASD at 6.1% to 24.7%. This risk rises to 36% to 95% with identical twins.
In addition, a current trend in early autism diagnosis for a child is that one or both parents seek an assessment for themselves as a result of the process. This, on occasion, can lead to a parent’s diagnosis.
While these scenarios suggest — and early genetic research findings weakly confirm — genetic lines of autism in families, Dr. Davis is cautious not to assume genetics are entirely the cause of autism. There are likely multifactorial causes.
“We don’t use genetics as a frontline factor for autism diagnosis,” she explains. “But once a diagnosis is made, genetics is usually discussed with the family. It’s suggested that 20% of kids diagnosed can have genetic lineage, but that research is still in its infancy. We’re currently gathering data at Mayo Clinic in the hopes of finding links.”
The outcome of this research will certainly help families know if autism runs in their family tree. It also will play a small part in expediting early diagnosis, but Dr. Davis is under no illusions that it will make the jigsaw puzzle of autism assessment any less difficult to carry out.
“There are still so many unknowns in this area,” says Dr. Davis. “Trying to figure out the pieces of these children, that’s what is so fascinating about autism, because the children are all so very different.”

Relevant reading
Mayo Clinic Guide to Raising a Healthy Child
Comprehensive guide that addresses the challenging variety of issues that parents face today.
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