ADHD and Sensory Processing: Overlapping Symptoms Explained

Swimming in Sensory Referrals 

As a school-based occupational therapist, the term “sensory” gets thrown around a lot these days. Twenty years ago, talking about sensory processing could get you accused of practicing “voodoo” (true story!). Now, it feels like everyone and their brother has a sensory problem. This shift has left many of us juggling sensory referrals, trying to untangle the “ADHD vs Sensory “debate.

Is it “Sensory or Behavior or ADHD”

When observing students with ADHD, the question is no longer just whether this is a “sensory or behavior”. ADHD is no longer viewed as a behavioral condition.

Behavior is only the visible outcome of what’s happening inside the brain and body. Instead, we need to ask whether there’s an issue with sensory processing or executive functions beneath the observable behavior.

The Overlap Found in Sensory Testing

Differentiating between ADHD and sensory processing issues can be challenging because of the significant overlap in symptoms and classroom difficulties. Research indicates that these conditions often co-occur, with sensory processing problems present in about 60% of cases of ADHD (Panda et al., 2023). 

When evaluating a student’s participation and performance patterns in the classroom, therapists commonly use the Sensory Processing Measure (SPM) and the Sensory Profile 2 (SP-2). The results for students with ADHD often show high correlations in these assessments, indicating sensory processing issues.  

However, this overlap doesn’t necessarily mean a sensory problem is present; it could be executive function challenges manifesting similarly (Brown et al., 2021).

Interconnected Executive Functions

This is because ADHD causes neurodevelopmental differences in the development of executive function for self-regulation.

Recent research has highlighted the relationship between sensory processing and executive functioning in children. Studies show that difficulties in sensory processing and executive functions often go hand in hand (Brown et al., 2021).

Research demonstrates a statistically significant predictive relationship exists between sensory processing as measured by the Sensory Profile-2 and executive function as measured by the Behavioral Inventory of Executive Functions -2 .

They found typical responses to sensory experiences were related to appropriate abilities for executive function : whereas, increased sensory reactivity was related to decreased abilities for executive function along with an increased expression of impulsivity, reduced attention, and decreased on-task behavior.

Findings indicate that children’s sensory processing and their executive functioning are strongly associated, indicating a predictive relationship between the two (Brown et al., 2021). 

This means a child with ADHD may display sensory sensitivities or seeking behaviors due to executive function difficulties, not a separate sensory processing condition.

Heterogeneity of Presentations 

There are three “presentations” of ADHD according to the DSM-5: primarily inattentive, primarily impulsive, or combined. The heterogeneity of the three presentations often manifests with correlated heterogeneity in sensory responses.

Sensory Problems and ADHD Primarily Impulsive Presentation

Difficulty with the executive function response inhibition is a hallmark of the impulsive presentation of ADHD.

These students will have difficulty inhibiting motor, verbal, perceptual, and emotional responses. The regulatory challenges associated with the Impulsive Presentation of ADHD may cause individuals to have substantial difficulty processing and regulating responses to sensory input.

These students may appear to fit the sensory profile of “sensory sensitivity” or “sensory seeking” , especially when young, with many of the below “sensory” behaviors observed in the classroom .

Hyperactivity and need for constant movement

• Motor restlessness , constant movement
• Rocking , leg shaking or other repetitive movements
• Love for intense stimulation like spinning or swinging
• Appears enjoy deep pressure: weighted blankets, bear hugs, roughhousing, jumping, grinding teeth, chewing on objects

Difficulty with Grading of Movement

• Misjudging the weight of objects, breaking things, spilling drinks
• Gripping things too hard, often breaking pencil leads
• Pressured , Illegible handwriting that under and overshoots the baseline, ripping paper when erasing

Hypersensitivity

Difficulty with inhibition may lead to extreme or heightened reactions to sensory stimuli .

• Tactile sensitivity: discomfort with certain textures and materials, avoidance of certain clothing
• Sound sensitivity: Bothered by environmental noise, hypersensitivity to noise, hears sounds others may not notice
• Interoception: Appears to have difficulty maintaining body temperature, regulating appetite, transitioning from hyper to lethargic quickly
• Visual hypersensitivity: Headaches from lights, easily distracted by movement or decorations or clutter on page and environment
• Sensory overload: Problems with inhibiting attention to stimuli overwhelms the brain with sensory information. We can’t just ignore it.
• Emotional Dysregulation : Difficulty regulating emotional responses to sensations.

Common Sensory Problems Associated with ADHD Primarily Inattentive Presentation

Difficulty with working memory and sustained attention is the executive function hallmark of the Primarily Inattentive Presentation of ADHD. Executive function difficulties with working memory, sustained attention and set shifting may create difficulty with registering sensory input. These children may appear to have a sensory profile of high threshold or sensory under-responsivity.

Interoceptive Awareness and Internal Regulation Difficulties

Difficulty paying attention to internal body cues may lead to difficulty with:

• Body temperature awareness and regulation: Without attending to the internal cues these are the students who are sitting in the winter coat in the 80 degree classroom with a bright red face .
• Appetite and feeding: misses hunger and thirst cues until energy and mood drops.
• Toileting behaviors: not going to the bathroom until it’s an emergency. Students with ADHD may have more frequent toileting accidents .

Proprioception Difficulties

Difficulty attending to proprioceptive input may lead to difficulty with:

• Poor body awareness: frequent bumping into objects, clumsiness, mystery bruises
• Poor muscle coordination: difficulty with regulation of movement from environmental feedback, frequent slumping or leaning
• Poor grading of movement/ pressure: Misjudging the weight of objects, spilling drinks, breaking things, illegible handwriting, ripping paper when erasing

Sensory Registration Difficulties

Students may be inattentive or hyperfocused due to difficulty relating, shifting and updating attention which may lead to :

• Missing environmental stimuli: visual, auditory , proprioceptive input
• Appear Too Much: excessively loud or noisy, making noise just to make noise
• Appear to Not Hear You ” Exhibit delayed responses to sounds
• Auditory Processing: Have difficulty processing spoken words, especially multi-step verbal directions (working memory)
• Have a high pain tolerance

Differentiating ADHD and Sensory Processing Disorder

Although sensory processing disorder (SPD) or sensory modulation disorder (SMD) is not currently recognized as a standalone disorder in the DSM, researchers consider ADHD and SPD to be distinct conditions. Research (Miller et al., 2012) has highlighted key differences when comparing ADHD and SPD , however they lack usability in the classroom context. 

• Comparison of Sensory Processing Patterns: Children with SPD show significant sensory difficulties across various systems compared to those with ADHD (Miller et al., 2012).
• Pain Sensitivity: Children with SPD often report higher pain levels and prolonged pain sensations the those with ADHD (Pfeiffer et al., 2015).
• Habituation: Children with SPD exhibit exaggerated responses to sensory stimulation and slower habituation compared to typically developing children. In contrast, children with ADHD show variability in their response magnitude and faster habituation (Herbert & Pollatos, 2012).

Classroom Takeaway 

ADHD is the most heterogeneous condition encountered in school-based practice, one of the reasons it is so grossly misunderstood.  The symptom severity of ADHD is contextually dependent.

Differentiating between ADHD and sensory processing difficulties can be challenging due to the significant overlap in symptoms and classroom behaviors. Research indicates that sensory processing problems are present in about 60% of cases of ADHD.

Executive function and ” sensory processing ” skills are interconnected neural processes that work together to produce observable behavior. At this time there is no way to separate them out into neat little categories or hierarchies.

Understanding the relationship between sensory processing and executive functions is crucial for effective and timely intervention. When swimming through the sensory referrals this fall , therapists can consider :

• Students with ADHD: When a child with ADHD shows sensory difficulties in the classroom , therapists can use their sensory lens to educate caregivers and create informed accommodations and scaffolds to remove the participation barriers associated with both sensory and executive function challenges. Integrating the two will significantly improve the child’s ability to cue, direct, process and regulate sensory information for classroom participation, reducing the cognitive load on the child.

• Students without ADHD: For children without a neurodevelopmental diagnosis who are exhibiting “sensory”, consider the possibility of co-occurring executive function challenges. While it’s not our role to diagnose, a holistic view of the child may reveal underlying executive function challenges contributing to the “ sensory “ picture. 

By understanding the interconnectivity of sensory processing and executive functioning, educators and school based occupational therapists can create supportive environments that enhance learning and daily functioning for students with ADHD.

Executive function and sensory processing are interconnected neural processes that work together in one unique nervous system to produce observable behavior.

Learn More About Executive Functions

To dive deeper into ADHD and executive functions and discover actionable strategies that can make a real difference, consider joining our upcoming course cohort of “The EASE Framework.“

References: 

Bishop, C., Brown, T., & Yu, M.-L. (2023). The relationship between school-age children’s interoceptive awareness and executive functioning: An exploratory study. British Journal of Occupational Therapy, 86(2), 116-129. https://doi.org/10.1177/03080226221128184

Cesari, A., Galeoto, G., Panuccio, F., Simeon, R., & Berardi, A. (2024). Evaluation instruments for executive functions in children and adolescents: An update of a systematic review. Expert Review of Pharmacoeconomics & Outcomes Research, 24(4), 487-508. https://doi.org/10.1080/14737167.2024.2311872

Romero-Ayuso, D., Ortiz-Rubio, A., Vidal-Ramírez, C., Pérez-Rodríguez, S., & Triviño-Juárez, J. M. (2022). Emotional intelligence, executive functions and sensory processing in daily life in children aged between 8 to 11 years: A pilot study. Occupational Therapy in Mental Health, 39(2), 137-155. https://doi.org/10.1080/0164212X.2022.2089435

Brown, T., Swayn, E., & Pérez Mármol, J. M. (2021). The relationship between children’s sensory processing and executive functions: An exploratory study. Journal of Occupational Therapy, Schools, & Early Intervention, 14(3), 307-324. https://doi.org/10.1080/19411243.2021.1875386

Engel-Yeger, B., & Mevorach Shimoni, M. (2023). The contribution of atypical sensory processing to executive dysfunctions, anxiety and quality of life of children with ADHD. Occupational Therapy in Mental Health, 40(2), 103-122. https://doi.org/10.1080/0164212X.2023.2220975

Panda, P. K., Ramachandran, A., Kumar, V., & Sharawat, I. K. (2023). Sensory processing abilities and their impact on disease severity in children with attention-deficit hyperactivity disorder. Journal of Neurosciences in Rural Practice, 14(3), 509-515. https://doi.org/10.25259/JNRP_22_2023

Miller, L. J., Nielsen, D. M., & Schoen, S. A. (2012). Attention deficit hyperactivity disorder and sensory modulation disorder: A comparison of behavior and physiology. Research in Developmental Disabilities, 33(3), 804-818. https://doi.org/10.1016/j.ridd.2011.12.005

Pfeiffer, B., Daly, B. P., Nicholls, E. G., & Gullo, D. F. (2015). Assessing sensory processing problems in children with and without attention deficit hyperactivity disorder. Physical & Occupational Therapy in Pediatrics, 35(1), 1-12. https://doi.org/10.3109/01942638.2014.904471

Herbert, B. M., & Pollatos, O. (2012). The body in the mind: On the relationship between interoception and embodiment. Topics in Cognitive Science, 4, 692-704.