Anxiety, ADHD, or Autism? What Testing Reveals When the Signs All Look the Same
Is it autism, ADHD, or anxiety? Dr. Joanna Kennedy explains how psychological testing tells the difference in children.
"We're pretty sure it's just anxiety."
Sometimes that's exactly right. And sometimes it's the opening line of a much more interesting conversation.
Anxiety is a fair first guess. It's the explanation parents hear most, the one teachers reach for, the one that fits almost any struggling child if you squint. The squinting is the problem. Autism, ADHD, and anxiety share so much surface behavior in children that separating them by observation alone is close to impossible, even for the adults who love the child and see them every single day. A kid who avoids the group, can't hold still, or unravels when plans change might be carrying any one of the three. Often more than one.
The distinction is important. Support built around the wrong explanation doesn't simply fall flat. It can teach a child that help doesn't work. So here's how the people who do this professionally actually pull these apart, starting in the testing room itself.
What a Clinical Psychologist sees that the rest of us miss
Dr. Joanna Kennedy, PsyD, a licensed clinical psychologist here at Pinnacle Counseling and Testing Center, has built her career around this question. She conducts developmental and psychological assessments for children and teens, including autism evaluations using the ADOS, and before joining Pinnacle she trained at Rady Children's Hospital's Autism Discovery Institute. When a family arrives certain the answer is anxiety, she doesn't argue with them. She watches.
They might be anxious, they might not want to look at me, they might not have much to say. But I'm really looking at how they're having a back-and-forth conversation, how they're responding to little things like dropping a pen. The quality of the social interaction.
Dr. Joanna Kennedy, PsyDLet's say a pen falls off a desk. Most children look up, or laugh, or say something about it. What a particular child does in that unscripted half-second can tell a clinical psychologist more than an hour of prepared questions. With ADHD, she tracks a different current entirely: a child who repeatedly misses what she just said, or who offers comments belonging to some other conversation. Not nervousness. Attention that keeps leaving the room.
One behavior, read three ways
Beneath the shared surface, these three conditions run on different machinery, and that machinery is what an evaluation actually maps. Take one of the most common referral concerns we hear at our Escondido office.
Dr. Kennedy describes her job as holding the diagnostic criteria against everything she observes directly and everything parents and teachers report, hunting for what's unique to each condition rather than what's shared. Restricted and repetitive behaviors, repetitive hand movements, and sensory processing differences point far more specifically toward autism than social withdrawal ever could. A pediatrician working inside a fifteen-minute visit, however sharp, simply isn't handed the time or the tools to run that comparison. That isn't a criticism of pediatricians. It's the reason psychological testing exists as its own discipline.
Anxiety wears disguises, especially in children
None of this makes anxiety a throwaway guess. It means anxiety in children is genuinely strange, and rarely resembles the adult version families expect. Dr. Clarissa Gosney, PsyD, a licensed psychologist at Good Day Mental Health in Ogden, Utah, who specializes in childhood anxiety, describes its most common childhood form as a child who can't quite advocate for their own needs or put distress into words at all.
It often looks like tummy troubles or tantrums.
Dr. Clarissa Gosney, PsyDThe stomachache the pediatrician can't explain. The blowup that arrives without warning. The slow retreat from activities a child once loved. Then there's the disguise that fools families most reliably, particularly with boys and with teenagers: plain old anger.
While moodiness is a common symptom with hormonal shifts during puberty, it can also be a sign of anxiety or depression. People with ADHD, whether children, teens, or adults, can seem to snap at what others may view as a minor annoyance.
Dr. Clarissa Gosney, PsyDCount the suspects behind one irritable thirteen-year-old: puberty, anxiety, depression, ADHD. ADHD involves differences in the prefrontal cortex, the brain's front office for planning, impulse control, and emotional regulation, so a minor annoyance landing on an overstimulated nervous system can produce a reaction that looks purely behavioral. Four candidate explanations, four very different responses. This is her argument for a formal diagnostic evaluation over the family guessing game, and it's a strong one.
Attention problems that have nothing to do with attention
School is where these mix-ups happen most, and Dallin Hendry, MEd, a doctoral student in school psychology at Utah State University, practicing under the supervision of Dr. Clarissa Gosney, PsyD, works at that exact intersection. He offers a correction to the most famous acronym in childhood mental health.
ADHD can be a misleading name. It's not so much a lack of attention as a lack of attention regulation. The attention is usually shifted onto something else.
Dallin Hendry, MEdA child with ADHD is always paying attention to something. The steering is what's different, not the engine. Anxious inattention arrives by another road altogether: a mind flooded with thoughts like "everyone will laugh at me" and "I'm going to fail this," leaving little bandwidth for the worksheet. From across a classroom, the two are indistinguishable. Both look like a kid staring past the page. Which is exactly why a real assessment includes asking the child directly what's happening inside, supported by questionnaires and structured observation, because inattention and anxiety are private experiences and the outside view keeps fooling everyone.
One case from his own assessment work makes the stakes concrete.
Sometimes what looked like a child refusing to work was actually a case of fight or flight, where they felt too overwhelmed and anxious to even begin. When we gave some coping strategies and accommodations, the attention concerns fixed themselves.
Dallin Hendry, MEdHad that child been waved through as ADHD on appearances, the plan might have led with stimulant medication for a nervous system that needed calming, not activating. He sees the same trap in report cards: a falling grade gets blamed on attention, when the real obstacle may be an undetected learning disorder or anxiety quietly taxing a child's ability to focus and learn. Grades announce that something is wrong. They stay silent on what.
The first diagnosis is sometimes just the loudest one
There's one more layer. These conditions frequently travel together, and the earliest diagnosis tends to go to whichever one makes the most noise, not whichever runs deepest.
Most often I'd say I see ADHD diagnosed first, and that masking, covering up autism.
Dr. Joanna Kennedy, PsyDA kindergartner's hyperactivity gets flagged within weeks. The quieter differences in how that same child connects socially may wait years for a close look. Dr. Kennedy sees the mirror image too: an autistic child identified early whose ADHD only becomes visible with age, eventually carrying both diagnoses accurately. Dr. Clarissa Gosney points to markers suggesting anxiety may be riding along with something larger rather than driving: diminished social reciprocity, restricted or repetitive behaviors, echoed or parroted speech (echolalia), constant fidgeting and drifting concentration even during calm moments, and heightened sensitivity in any of the senses. When worry arrives with that company, a careful clinical psychologist widens the search rather than closing the file.
Getting the order right
Why insist on this level of precision? Because when conditions overlap, sequence becomes strategy. Dr. Clarissa Gosney offers a case that shows the logic: a child whose anxiety grows out of ADHD, born from the repeated sting of regretting things blurted on impulse. Treat that child's worry alone and the impulsivity keeps manufacturing fresh material for it. Address the ADHD first, and the anxiety loses its supply line. Same two diagnoses, and everything hinges on knowing which one sits upstream.
That knowledge is what a comprehensive evaluation buys. Not a label for its own sake, but a map of which intervention goes first, which school accommodations actually fit, and what the adults around the child should do differently on Monday morning.
Before you book anything
If your family is circling this decision, here's the honest version of what you're signing up for. You don't need to arrive with the answer. Bring your observations, the specific moments that worry you, and let the evaluation do the sorting. And if the idea of a diagnosis itself feels heavy, this is what Dr. Kennedy tells worried patients.
At the end of the day, the goal of that diagnosis is to help us understand the child so that we can work on things they can do differently, but more importantly, so everyone around them understands them better.
Dr. Joanna Kennedy, PsyDWhat families want to know
Is it possible my child has two of these, or all three?
Not only possible but routine. Anxiety and ADHD are frequent companions, and autism and ADHD overlap often enough that finding one prompts the psychologist to check carefully for the other. Good testing keeps asking questions after the first plausible answer appears.
How young is too young for this kind of evaluation?
These assessments can begin to be discussed as early as age three. Whether testing is appropriate at that age is a case-by-case decision made with the evaluating psychologist, based on the specific concerns and the child's developmental stage.
Won't a label just follow my child forever?
An accurate diagnosis works less like a sticker and more like a key. It unlocks school supports, appropriately targeted therapy, and a shared understanding among the adults in your child's life. Families tell us the evaluation was a relief far more often than a burden.
How do we explain testing to our child?
Frame it as time with someone whose whole job is figuring out how kids' brains work best, mostly through activities, puzzles, and conversation. Nothing to study for, no way to fail, no needles anywhere. Most children walk out having enjoyed themselves.
Do you see families outside Escondido?
Yes. We regularly work with families across North County San Diego and southwest Riverside County, including Temecula, Murrieta, and Menifee. Comprehensive child testing is scarce across this region, so families often travel a bit further than they'd like for it.
Ready for real answers instead of best guesses?
Dr. Joanna Kennedy provides comprehensive developmental and psychological assessment for children, teens, and adults in Escondido, serving North County San Diego and southwest Riverside County.
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