In a recent episode of In the Field: The ABA Podcast, I sat down with Nicole Stewart, a board certified and licensed behavior analyst with over 15 years of experience, to talk about what ADHD really looks like in kids and adults, and why it is so often overlooked in clinical work. Nicole's path took her from pre-med to the New England Center for Children, into clinical direction, and now into private practice, where she offers therapy, parent coaching, and ADHD focused training for organizations. She also co-hosts the podcast Reinforcing Conversations.
We talked about the neurobiology behind ADHD, why girls and high achievers are so often missed, and what it actually takes, clinically and organizationally, to support both learners and staff who have ADHD.
Nicole starts with the brain. ADHD comes down to how the brain regulates dopamine, one of the body's chemical messengers. Researchers are not certain whether people with ADHD have a dopamine deficiency or whether their receptors do not take in dopamine properly, but the result is the same: ADHD brains do not regulate dopamine well.
That has downstream effects on brain development itself, including the prefrontal cortex (where executive functioning lives) and the basal ganglia (where emotional reactions and impulses originate). Functional MRIs show that ADHD brains develop and activate differently than neurotypical brains.
Nicole draws a direct comparison to diabetes: just as the pancreas does not produce insulin properly in diabetes, the ADHD brain does not regulate dopamine properly. Both are medical diagnoses, not simply behavior patterns to extinguish.
ADHD shows up in three diagnostic classes: inattentive, hyperactive, and combined. Behaviorally, that can look like daydreaming, poor working memory, or difficulty recalling recent events, even when a person can recall highly specific details from years earlier if the right conditions trigger the memory.
Nicole compares this to computer storage versus processing speed: people with ADHD can store a lot of information, but pulling it up on demand is the harder part.
Hyperactivity is not always external. Internal hyperactivity, a constant stream of internal dialogue, often gets missed entirely, especially in the inattentive presentation, because the person does not look "hyperactive" in the way most people expect.
One of the clearest points in this episode: behavioral contrast between home and school is a major red flag that gets ignored too often. Nicole describes a common pattern where parents report significant struggles at home (meltdowns, needing constant reminders, emotional volatility) while teachers report a child who "sits still" and "does fine."
That contrast usually means the child is masking, holding it together through the school day and then falling apart once they feel safe enough to let their guard down. Standard assessments like the Vanderbilt rely heavily on teacher report, which means masked presentations, especially common in girls and high achievers, can result in missed or delayed diagnoses.
Nicole points to research suggesting kids with ADHD receive roughly four to five times more corrective feedback than their neurotypical peers for the exact same task. A typically developing child might need two reminders to put their shoes on; a child with ADHD might need seven.
That repeated correction is not because the child wants to be told seven times. It often reflects something else going on: distraction, difficulty initiating a task, low dopamine in that moment, or an unrelated need entirely. Over time, that disproportionate feedback compounds into internalized shame: "Why can't I do it? Why is mom always mad at me? I can't do anything correctly." The external corrections become internal ones, and that cycle is worth understanding before assuming a behavior plan needs a bigger reinforcer.
Nicole describes executive functioning as the brain's CEO, the set of skills behind higher order thinking: task initiation, working memory, cognitive flexibility, impulse control, planning, and task persistence. Executive functioning does not fully develop until around age 25, and people with ADHD can show up to a three year developmental delay in these skills.
That delay creates real mismatches. A child might be intellectually advanced in conversation while having the executive functioning of a much younger child, which leads adults to expect more than the child's brain is currently able to deliver.
Emotional regulation is closely tied to executive functioning. Nicole describes it as the ability to stay calm and persist through difficult emotions, and notes that many people with ADHD experience emotions as sudden, large waves rather than something that builds gradually. She also raises a clinical observation (not yet something she has researched formally): the fight or flight response in some ADHD clients seems unusually easy to trigger, so something as small as being bumped in a hallway can set off a disproportionate reaction.
Once a child has that reaction and gets told they are "fine" or overreacting, shame builds, and the child becomes hypervigilant about having the same response again, which paradoxically makes the reaction more likely the next time.
A key clinical point from this conversation: coping skills are frequently taught before emotional recognition, and that order does not work. Nicole describes the common but incomplete approach of handing a child a sensory bottle or a calm corner without first teaching them to identify what they are actually feeling and where they feel it in their body.
Different emotions call for different coping strategies. Anger might call for something physical, like ripping paper. Sadness might call for rest or quiet. A single generic coping tool will not match every emotional state, and kids need explicit teaching to connect a specific feeling to a specific, effective response.
Nicole also flags rejection sensitivity as common in ADHD, where neutral comments or events get internalized as personal rejection (a sibling's basketball game getting attention is interpreted as "mom loves them more").
This distinction comes up repeatedly in the episode. When a child with ADHD is not mastering a skill in discrete trials, the instinct is often to add more reinforcement: a denser schedule, more tokens, a bigger reward. Nicole pushes back on that default.
The better first question is whether this is a skill deficit (they do not know it) or a performance deficit (they know it but are not demonstrating it consistently). If the task itself is not engaging or the materials are not novel, no amount of external reinforcement will sustain attention long term, because ADHD motivation is heavily interest based.
The same distinction applies to adult staff. Nicole notes that with adults, clinicians often default to assuming a performance deficit (assuming the person is choosing not to comply) when it may actually be a skill deficit, particularly for staff who are undiagnosed or were never taught certain foundational skills.
When asked what strategy she sees most underused with this population, Nicole didn't hesitate: pairing. Establishing yourself as a conditioned reinforcer through a strong relationship is, in her experience, the single most effective lever for ADHD treatment.
When a child does not have a positive relationship with the clinician or their parents, every other strategy becomes less effective: long reinforcement schedules, discrete trials, challenging tasks, all of it. Build the relationship first, and the rest of the toolkit works better. Nicole notes she does not believe pairing should be treated as one strategy among many; given how disproportionately many corrective interactions kids with ADHD already experience, rapport is the foundation that makes everything else possible.
Nicole identifies the most common mistake she sees as a lack of individualization tied to ADHD specifically, separate from autism. If a learner with both autism and ADHD is shutting down during discrete trials, the fix is not automatically a bigger reinforcer. It might be that the task itself needs to be more enjoyable, the materials need to be more novel, or the format needs more variety, all of which can be harder to implement in a tiered ABA model where discrete trials are often chosen for ease of prep and instruction.
She also points to response effort as a factor that gets overlooked. Negative attention can be automatically reinforcing for ADHD brains, so if accessing a break requires a fight (escalating to aggression first), that pathway gets reinforced. Reducing the response effort to access regulation, offering a break proactively when a child appears dysregulated rather than requiring them to ask for it first, can reduce reliance on more severe behavior to get the same outcome.
On the organizational side, Nicole's starting point is training. When BCBAs® and RBTs® understand ADHD specifically, not lumped in with autism, individualization improves across the board. She places ADHD as a top priority among comorbid diagnoses, given how frequently it co-occurs with autism in more traditional ABA models.
She also points out a long standing diagnostic issue: before the DSM-V, autism diagnoses often absorbed every other symptom a child presented, including OCD like behaviors, anxiety, and ADHD. Without recognizing the actual comorbid condition, treatment becomes far more trial and error than it needs to be.
This episode does not stop at client care. Nicole also coaches adults with ADHD, work that grew out of her time as a BCBA® supervisor, where she found herself teaching trainees soft skills, executive functioning, time management, and emotional regulation that were never explicitly taught elsewhere.
For organizations supporting staff, she recommends:
ADHD is a medical and neurobiological condition, not just a set of behaviors to extinguish.
Masking in girls and high achievers can delay diagnosis and leave real struggles invisible.
Corrective feedback disproportionately affects kids with ADHD, often four to five times more than their peers, fueling shame and avoidance over time.
Pairing and rapport outperform bigger reinforcers or denser schedules when working with ADHD learners.
Universal design for learning benefits every learner and every staff member, not only those with ADHD.
Skill deficits and performance deficits require different solutions, and ADHD often hides as the latter.
Organizational training on ADHD, alongside autism and other comorbid diagnoses, improves individualization across the board.
ADHD shapes how learners and staff experience every part of ABA, from the therapy room to the supervision meeting. Understanding the neurobiology and individualizing accordingly is not optional, it is the work. To hear the full conversation with Nicole Stewart, listen to this episode of In the Field: The ABA Podcast.
For more resources on onboarding, supervision, and staff development, visit Sidekick Learning.