When a young child struggles to connect with others, parents often notice first. A mother might describe her child as “in their own world,” while another might say her child “can’t sit still long enough to play.” These early observations — sometimes subtle, sometimes pronounced — can lead to understandable confusion. Both Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) can appear early in development and share overlapping characteristics: inconsistent eye contact, distractibility, impulsivity, and difficulties in social settings. Yet beneath these surface similarities lie distinctly different functions driving the child’s behavior.
One child may be full of energy — darting between toys, speaking rapidly, and losing interest before a game even begins. Another might seem quiet and self-contained, content to repeat the same routines but slow to respond when spoken to. Both children might appear inattentive, socially inconsistent, or disengaged, and yet what drives these behaviors can be entirely different. Understanding not only what a child does but why they do it is at the heart of differentiating Autism Spectrum Disorder (ASD) from Attention-Deficit/Hyperactivity Disorder (ADHD). And for many children, these two conditions are not separate at all but intertwined, shaping how they experience, perceive, and respond to the world around them.
Autism and ADHD are among the most common neurodevelopmental conditions in childhood, and research has shown that their overlap is far more frequent than once believed. Studies estimate that between 30% and 50% of children with autism also meet criteria for ADHD, while 20% to 30% of children diagnosed with ADHD present with features of autism (Antshel & Russo, 2019; Yerys et al., 2019). This comorbidity is not surprising given that both conditions affect the developing brain systems involved in social functioning, attention, and regulation. However, each disorder retains distinct features that must be understood to provide accurate diagnosis and effective intervention. Recognizing when autism and ADHD co-occur—and understanding the function of the behaviors associated with each—is key to helping children reach their fullest potential.
In autism, social differences reflect a fundamental divergence in how the brain perceives and interprets social information. The world of people, with its nuanced expressions, gestures, and tone, is not always intuitively understood. A child with autism may fail to notice when a parent smiles or not recognize that eye contact conveys emotional connection. They may not automatically grasp the meaning behind another child’s invitation to play or the unspoken rules that guide turn-taking and shared enjoyment. These behaviors are not born from disinterest or defiance — they reflect a neurological difference in social perception. Neuroimaging studies show that children with autism display reduced activation in brain regions associated with social cognition, such as the fusiform gyrus and superior temporal sulcus (Pelphrey et al., 2011). The challenge lies in decoding social information, not necessarily in wanting connection.
In ADHD, the difficulty emerges from an entirely different mechanism. A child with ADHD generally understands social expectations but struggles to meet them consistently because of inattention, impulsiveness, and hyperactivity. They might interrupt a peer mid-sentence, lose track of what’s being said, or abandon a game halfway through. Their mind shifts rapidly, and their body often follows. The child’s social missteps arise from inconsistency, not misunderstanding. As Barkley (2015) describes, ADHD represents a developmental delay in executive functioning — the mental processes responsible for planning, regulating impulses, sustaining attention, and managing emotions. When ADHD and autism occur together, these overlapping vulnerabilities can compound one another, resulting in a child who not only struggles to interpret social information but also to maintain the focus and control required to use it effectively.
This interaction between perception and regulation creates a complex behavioral picture. The child may genuinely want to play with peers but misinterpret their intentions, become overstimulated by sensory input, and then impulsively retreat or react. What appears to be social avoidance may instead reflect both the processing challenges of autism and the attentional dysregulation of ADHD. For example, a child with autism alone may not initiate shared play because they do not recognize its reciprocal nature; a child with both autism and ADHD may try to initiate play but do so in a way that feels intrusive or poorly timed, leading to social rejection. Both outcomes reflect difficulty with social connection, yet their functions—and therefore the necessary supports—are distinct.
Eye contact is one of the earliest and most striking examples of this functional difference. For a child with autism, limited eye contact reflects a neurological difference in meaning-making. The eyes may not naturally draw attention or convey significance, making gaze less central to understanding others. In ADHD, inconsistent eye contact reflects fluctuating attention rather than absence of interest. The child may look away mid-conversation not because faces are confusing, but because their focus has shifted elsewhere. This distinction illustrates a broader theme: in autism, social connection may not emerge naturally because of differences in perception, while in ADHD, it falters because of challenges in sustaining engagement.
Play behavior also helps differentiate these patterns. A child with autism often demonstrates repetitive or highly specific play — lining up toys, spinning wheels, or fixating on particular objects or routines. Pretend play may be limited or scripted, reflecting differences in symbolic thinking and imaginative flexibility (Baron-Cohen et al., 2000). When ADHD co-occurs, the child’s play may appear more varied but also chaotic, characterized by disorganization and impulsivity. They may bounce between games, struggle to follow rules, or lose patience with peers. In children with both conditions, play may reveal a blend of features — rigidity and repetition punctuated by bursts of restless activity. Recognizing this pattern allows parents and clinicians to distinguish behaviors that arise from sensory or social-cognitive differences from those driven by impulsivity or poor self-regulation.
Language development offers another window into the interplay between the two conditions. Children with autism often exhibit pragmatic language deficits — the social use of language. They might repeat phrases (echolalia), speak in a mechanical tone, or fail to adjust their speech to fit context. A child with ADHD, by contrast, may talk excessively or interrupt frequently, their speech marked by impulsivity rather than atypical structure. When the two conditions coexist, communication may vacillate between both patterns — socially rigid one moment, impulsively scattered the next. These alternating styles can make it difficult for caregivers to know whether a child “can’t” communicate effectively or simply “can’t regulate” their communication in the moment.
Emotional and behavioral regulation often represent the area of greatest overlap and greatest challenge. Both children with autism and those with ADHD can experience emotional volatility, but the underlying causes differ. A child with ADHD may erupt in frustration when told “no,” acting impulsively and recovering quickly once the moment passes. A child with autism may have a similar outburst, but it often reflects sensory overload, unexpected change, or difficulty tolerating transitions. When both conditions are present, emotional regulation becomes a balancing act between external stimuli and internal control. The child may become overwhelmed by sensory experiences and simultaneously lack the inhibitory mechanisms to manage their reaction. Robertson and Baron-Cohen (2017) found that sensory hyperreactivity — common in autism — can amplify ADHD-related restlessness, creating a cascade of emotional and behavioral dysregulation that is often misinterpreted as defiance.
For these children, intervention must be multifaceted and deeply individualized. Evidence-based therapies for autism — such as Applied Behavior Analysis (ABA) and Naturalistic Developmental Behavioral Interventions (NDBIs) emphasize social communication, joint attention, and adaptive functioning (Zwaigenbaum et al., 2015). These approaches teach the foundational social skills that the autistic brain does not naturally acquire. For ADHD, treatment focuses on enhancing executive functioning and self-regulation through behavioral parent training, structured environments, and, when appropriate, medication. When autism and ADHD coexist, both domains must be addressed concurrently. Improved attention and regulation through ADHD-focused interventions can enhance participation in autism-based therapies, while structured social-learning strategies can reduce the interpersonal conflicts and frustration that accompany ADHD symptoms.
Receiving both diagnoses can feel overwhelming for families, but it often brings clarity rather than complication. Autism explains how a child perceives the social world, while ADHD explains how they navigate within it. One captures the processing differences that make social connection effortful; the other captures the regulatory difficulties that make consistency hard to sustain. Together, these diagnoses provide a more complete understanding of the child’s neurodevelopmental profile and point toward a treatment plan that is both comprehensive and compassionate.
What ultimately matters most is not the label but the insight it offers into a child’s needs. A child who seems inattentive may not be disinterested in them. They may be distracted by competing sensory input or overwhelmed by a social world that feels unpredictable. Another who appears withdrawn may be protecting themselves from overstimulation while struggling to organize their attention. When caregivers and clinicians look beyond the behavior itself and consider the function beneath it — what it communicates about how the child experiences the world — they move from correction to connection.
Understanding that autism and ADHD can exist separately or together reframes how we view difference itself. These are not disorders of will or motivation but variations in neurodevelopment that shape how a child learns, feels, and relates. Through early identification, integrated intervention, and patient understanding, children with both autism and ADHD can learn to engage meaningfully with others, regulate their worlds more effectively, and build on their inherent strengths. Every behavior tells a story, and when we take the time to listen to it, we see not just what a child is doing, but why — they begin to write that story with us, in connection rather than isolation.
References
Antshel, K. M., & Russo, N. (2019). Autism spectrum disorders and ADHD: Overlapping phenomenology, diagnostic issues, and treatment considerations. Current Psychiatry Reports, 21(5), 34.
Barkley, R. A. (2015). Attention-Deficit Hyperactivity Disorder: A Handbook for Diagnosis and Treatment (4th ed.). Guilford Press.
Baron-Cohen, S., Tager-Flusberg, H., & Cohen, D. J. (2000). Understanding Other Minds: Perspectives from Developmental Cognitive Neuroscience. Oxford University Press.
Pelphrey, K. A., Shultz, S., Hudac, C. M., & Vander Wyk, B. C. (2011). Constraining heterogeneity: The social brain and its development in autism spectrum disorder. Journal of Child Psychology and Psychiatry, 52(6), 631–644.
Robertson, C. E., & Baron-Cohen, S. (2017). Sensory perception in autism. Nature Reviews Neuroscience, 18(11), 671–684.
Yerys, B. E., Wallace, G. L., Sokoloff, J. L., & Kenworthy, L. (2019). Attention deficit/hyperactivity disorder symptoms moderate cognition and behavior in children with autism spectrum disorders. Autism Research, 12(2), 247–258.
Zwaigenbaum, L., Bauman, M. L., Choueiri, R., et al. (2015). Early identification and interventions for autism spectrum disorder: Executive summary. Pediatrics, 136(S1), S1–S9.*
