Reviewed by Alexandra Vierling, Pediatric Nurse Practitioner and Head of Medical Services at Soar Autism Center
Toddlers climb, run, melt down, and ignore their names sometimes. So when your child seems more active, more distracted, or harder to connect with than other kids, it’s hard to know what you are seeing. Is it attention-deficit/hyperactivity disorder (ADHD)? Autism spectrum disorder (ASD)? Both? Or just typical toddler behavior?
This ADHD vs. autism guide is for parents of children 18 months through age 6 who may be wondering if their child’s behavior is part of typical development, or if there may be something else in play. It explains why the same behavior can stem from different causes, why autism can be accurately evaluated years before ADHD, and what you can do now.
When we’re evaluating your child for any developmental concern, one behavior on its own doesn’t tell us much. We’re looking more for coupled behaviors and patterns over time. The most important thing to remember is that any diagnosis is not a reflection on your child’s upbringing or your parenting. It’s simply more answers to help you provide the support they need.
ADHD vs. Autism: The Short Version
- ADHD mainly affects attention, activity level, and impulse control. A child with ADHD typically wants to connect but has a hard time slowing down, waiting, or staying with one thing. Some of these children struggle with self-regulation and peer rejection as a result of impulsive behavior.
- Autism mainly affects social communication and connection, along with restrictive, repetitive behaviors, a strong need for sameness, and sensory differences.
Same Behavior, Different Reasons
In young children, many behaviors look identical from the outside. The question that helps most is why it’s happening. As you read, keep in mind this chart is a tool to begin a conversation with your child’s care team, not a way to diagnose any behavior; the patterns are general, every child is different, and some children show some of both. Additionally, many of these behaviors are expected in younger children, so also keep in mind how their behavior matches, or doesn’t, their peers.
| What you see | Typical toddler behavior | When it may point more toward autism | When it may point more toward ADHD |
|---|---|---|---|
| Not responding to their name | Tunes you out when busy with something fun, but turns when you call again or try a new way. Most babies look when called by their name by around 9 months. | Your child is deeply absorbed and doesn’t seem to notice voices, even familiar ones. Patterns that indicate difficulty forming personal connections. | Your child hears you but is already on to the next thing |
| Running off | Wanders toward whatever catches their eye, and usually stops or comes back when you call. Very common from 18 months to 3 years. | Heading toward something specific over multiple instances, like a fan, water, or a favorite spot. Or, running to avoid certain situations, often in a way that feels unsafe. | Darting in every direction, drawn by whatever is newest |
| Meltdowns | Tantrums are common from about 18 months to 3 years, especially when tired, hungry, or told no. They usually settle with comfort and a little time. | Triggered by a change in routine, being told no, a sound, a texture, or something not going as expected | Triggered by impulsivity, waiting, being told no, or having to stop something fun |
| Lining up or dumping toys | Both are common ways to play. Toddlers line things up or dump bins, then move on to other kinds of play. | Lining up, sorting, or repeating the same play the same way in a way that becomes rigid | Dumping, moving on quickly, and leaving a trail behind |
| Not playing with other kids | Under age 3, most toddlers play next to other kids more than with them. Back-and-forth play with other children grows between ages 3 and 4. | Less interest in sharing attention, smiles, or back-and-forth play, including with you and other familiar grown-ups. Often are more interested in a toy or object than the others in the room. They sometimes have difficulty understanding when a child is initiating interactions with them (you can reword that) | Wanting to join in, but grabbing, interrupting, or not waiting a turn |
| Talking | Words grow quickly between 18 months and age 3, and repeating words they hear is part of how toddlers learn to talk. | Delayed speech, echoing words, or using words mostly to ask for things | Lots of talking, interrupting, or blurting things out |
| Constant movement | Toddlers are busy. Lots of climbing and running is expected, and most can slow down for a favorite book, song, or snuggle. | Repeated movements like hand flapping, rocking, or spinning that seem to be calming or an outlet for excited energy | Climbing, running, and trouble sitting still, even when tired |
One behavior on its own rarely means much. Look for patterns. Does it happen often, in more than one place, and with more than one person? Does it get in the way of play, learning, or safety? If a few rows in the autism or ADHD columns sound like your child, note them in the one-week log below and bring it to your pediatrician.
Behaviors to Keep an Eye on or Ask your Pediatrician About
These go a step past typical toddler behavior. None of them means your child has autism or ADHD, but they’re worth writing down and bringing up at your next visit.
Signs of autism to ask about
- Rarely points, waves, or brings you things just to share them by around 18 months
- Few or no words by 16 months, or no two-word phrases by 24 months
- Rarely looks where you point, or doesn’t often turn when you call their name
- Gets very upset by small changes, or plays the same way every time
- Strong reactions to sounds, textures, or lights, or seeks out spinning or pressure again and again
Our guide to the signs of autism covers these in more detail.
Signs of ADHD in Toddlers to Keep an Eye On
An active toddler doesn’t have ADHD by default, they’re active by nature. However, if these observations don’t diminish as they get older or they get in the way of daily living or academic performance, or are bringing up questions of safety, it’s worth noting and mentioning to your pediatrician when your child:
- Is in constant motion and rarely slows down, even when tired
- Has a much harder time waiting, taking turns, or sitting through a short story than other children the same age
- Acts before thinking in ways that are unsafe, like running into the street again and again
- Shows these patterns in every setting, at home, daycare, and with family
At any age
If your child stops using words or skills they used to have, talk with your pediatrician soon. That’s worth a call, not a wait-and-see.
Can You Have Autism and ADHD?
Yes. A child can have both. A national population-based study estimated that 43.8% of U.S. children with autism also had attention-deficit/hyperactivity disorder. This co-occurring combination is often referred to as AuDHD.
When a child has both, the traits can pull in different directions. A child may crave sameness and also get bored quickly, or love one topic deeply and still find it hard to sit still. These differences can sometimes cause parents to fixate on questions around “is this ADHD?” or “is this autism?” when, in fact, it is both.
“We often hear families wondering whether their child has trouble holding a conversation because their brain is moving so quickly, or instead, if they’d prefer to be off in their own world. With AuDHD, it’s a bit of both,” says Alexandra “Lexi” Vierling, CPNP, PMHS, Head of Medical Services at Soar Autism Center.
A diagnosis of one doesn’t rule out the other, so if something still doesn’t fit after one diagnosis, it’s OK to ask about the other.
“Treating ADHD in an autistic child is not the same as treating ADHD in isolation,” said Alexandra “Lexi” Vierling, CPNP, PMHS, Head of Medical Services at Soar Autism Center. “Challenges with attention or regulation may also be influenced by communication differences, sensory experiences, sleep and other factors. When families, therapists and medical providers compare what they are seeing across settings, we can better understand what may be driving those challenges and develop a coordinated plan that supports the child’s daily life and therapy goals.”
What an Evaluation Looks Like
No single test looks at autism and ADHD at the same time. Clinicians look at how your child communicates, plays, moves, pays attention, and responds to people, over time and in more than one setting. The path looks different for each one, mostly because of timing.
Why Autism Can Be Evaluated Years Before ADHD
- Autism can be evaluated early. The American Academy of Pediatrics (AAP) recommends autism screening at the 18-month and 24-month well visits, and the early signs of autism often show up in the first two years. Soar Autism Centers that offer diagnostic evaluations see children starting at 18 months.
- ADHD is usually diagnosed later. The AAP’s ADHD diagnosis guidelines are written for children ages 4 to 18, because high energy and short attention are part of being very young. However, in some cases, ADHD is diagnosed earlier by specialists.
So many families of toddlers look into autism first, then revisit attention and activity level closer to school age.
If You’re Wondering About Autism
If you’ve noticed potential signs of autism in your young child and aren’t sure where to start, a typical path of next steps includes:
- Talking with your pediatrician. Screens for autism at the 18-month and 24-month well visits and listens to your concerns.
- Taking a quick screener, if your child is 16 to 30 months. The free Modified Checklist for Autism in Toddlers, Revised (M-CHAT-R) is a questionnaire you complete yourself to help decide whether to ask about a more formal evaluation.
- Requesting an autism evaluation. If your pediatrician or other care provider has recommended seeking an evaluation, or an autism screener has indicated the potential for autism, a formal diagnosis can help give you answers and access to resources. At Soar, we offer diagnostic evaluations, conducted by a licensed psychologist who leads a comprehensive intake conversation and uses the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) and the Vineland Adaptive Behavior Scales, Third Edition (Vineland-3).
- Enrolling in autism therapy. Once a formal diagnosis is received, families may take those results to any therapy provider they feel comfortable with. Early diagnosis of autism in young children can unlock access to autism care covered by insurance or other medical coverages and allows children to achieve higher outcomes and to learn key skills to help them more easily navigate the world around them.
If you want to see each step from first concern to results, getting an autism diagnosis for your child walks through the autism process.
If You’re Wondering About ADHD
If you have questions about ADHD, it’s a good step to start with your pediatrician as well as others who your child interacts with. Get input from your family, your child’s teachers, therapists, and other caregivers about their behaviors. This information can give you a sense of what’s typical behavior in a young child or what warrants a deeper look with your child’s medical team. It can also be useful in informing a formal diagnosis, as AAP guidelines recommend including this information within checklists or rating scales.
At Soar, through our medical services*, pediatric nurse practitioners with specialized training in developmental and behavioral pediatrics offer evaluation and management for co-occurring conditions with autism, like ADHD. These appointments help give you additional answers more quickly if new concerns or behaviors have arisen, since your whole care team will be in communication with one another, as well as with you.
You Don’t Need a Clear Answer to Get Help Now
Waiting to find out whether it’s autism, ADHD, or both can feel like being stuck. You are not.
- Early intervention looks at development, not labels. Every state and territory has an early intervention program for babies and toddlers under 3 with developmental delays or disabilities. Services are free or reduced cost for children who are eligible, and you don’t need a doctor’s referral to call your state’s program and ask for an evaluation.
- Routines and play help either way. Predictable routines, short and clear directions, and play built around what your child loves support children with autism, ADHD, or neither.
- Therapy usually follows a diagnosis. In most cases, a diagnosis is needed before therapy begins, which is one more reason not to wait on an autism evaluation when you have concerns. If you have concerns, an evaluation can give you answers and options, and your family decides what comes next.
A One-Week Log to Bring to Your Pediatrician
Pediatric visits are short. A week of notes shows the pattern better than memory can. Copy this table into your phone’s notes or print it:
| Day and time | What happened | Where, and who was there | What happened right before | How long it lasted |
|---|---|---|---|---|
| Example: Tues, 5 pm | Did not respond to name, kept spinning the wheels of a car | Living room, dad and sister | Came home from daycare | About 10 minutes |
Add one or two short phone videos of typical moments. Then bring these questions:
- What did my child’s 18-month or 24-month autism screening show?
- Does what I am describing sound more like attention, social communication, or both?
- Should we look into an autism evaluation now, or watch and check back? When?
- Can you connect us with our state’s early intervention program?
Wondering whether it’s time for an autism evaluation? Our care team can talk through what you are seeing, what an evaluation involves, and your options, with no referral needed. Make an appointment to schedule a call.
*Medical Services are not currently available in Pennsylvania at CHOP-Soar locations.
FAQs
What Is the Difference Between ADHD and Autism?
Autism mainly affects social communication, along with repeated behaviors, a need for sameness, and sensory differences. ADHD mainly affects attention, activity level, and impulse control. In general, children with autism often seek sameness and find connection harder, while children with ADHD often seek novelty and want to connect but struggle to slow down.
How Do Sensory Differences Show Up in Autism and ADHD?
Both can involve sensory differences. In autism, a child may be strongly bothered by certain sounds, textures, or lights, or may seek out specific sensations like spinning or pressure, and the reactions tend to be consistent. In ADHD, sensory seeking often looks like constant movement, touching everything new, or having aversions to textures. An occupational therapist can help identify your child’s sensory needs.
What Does AuDHD Mean?
AuDHD is a term some people use to describe having both autism and ADHD. It’s not a separate diagnosis. A child with both receives two diagnoses, and their support is planned around both.
At What Age Can ADHD Be Diagnosed?
The American Academy of Pediatrics’ diagnosis guidelines for ADHD are written for children ages 4 to 18, so most pediatricians wait until around age 4. If you have concerns about a younger child, it is recommended to seek out a developmental pediatric specialist. Autism can be evaluated much earlier, starting at 18 months.
When Is ADHD Awareness Month?
ADHD Awareness Month is in October. It’s a time to share reliable information about ADHD and reduce stigma, and a good reminder to ask questions if your child’s attention or activity level has you wondering.
Does Soar Help Children Who Have Both Autism and ADHD?
Yes. Soar’s therapy plans are built around each child’s whole profile and at Soar centers that offer medical services, pediatric nurse practitioners provide evaluation and management for co-occurring conditions like ADHD, working alongside your child’s therapists.
