Understanding High Sensitivity, Autism, ADHD, and AuDHD

Where They Overlap and Where They Differ

As conversations about neurodiversity have expanded across social media and popular culture, many people who identify as highly sensitive have begun questioning whether their experiences overlap with, resemble, or even fall under conditions such as autism or ADHD. This has created a surge of confusion, but also a real hunger for clarity. In this article, I explore the relationship between Sensory Processing Sensitivity (SPS), autism, ADHD, and the increasingly popular term AuDHD, while honouring both the science and lived experience. My aim is not to divide, diagnose, or pathologise, but to offer a grounded, compassionate framework that helps you understand yourself more deeply.

Before we move into the distinctions, it feels important to say something at the outset that recent research is making increasingly clear: these traits and conditions are highly correlated; they exist on shared dimensions of human experience, and at the same time they are also distinct in meaningful ways. Holding both truths at once feels to me to be the most honest and accurate.

Why This Conversation Matters Now

Over the past decade, diagnostic language has entered everyday life at a rapid pace. Behaviours that were once seen as personality traits, stress responses, or signs of environmental overwhelm are now frequently interpreted as symptoms of neurodevelopmental disorders. Many people find this validating, and others feel more confused than ever. Beneath all of it, one question remains largely unexamined: What if some of what we call “disorders” are actually context-dependent responses shaped by biology, environment, culture, and experience?

I find myself reflecting on how readily mental, emotional, and physical distress can be framed as illness requiring biochemical intervention, while demographic factors, early experiences, chronic stress, trauma, and social context sometimes remain in the background. This is not a questioning of anyone’s diagnosis or of the medication and support that many people rightly depend upon, all of which can be genuinely life-changing and necessary; it is more a wish that the wider story around a person, the conditions they have lived within and the meaning their experiences hold, might be held alongside the clinical picture rather than left out of it. Diagnosis can be profoundly empowering and validating, and at the same time I find myself wishing that the compassion and accommodations a diagnosis unlocks were available to everyone who needs them, whether or not they hold a formal label.

At the same time, there has been a significant rise in identification with neurodiverse labels, particularly autism, ADHD, and the combination AuDHD. These terms are increasingly used as umbrella categories that group together a wide diversity of behaviours, emotions, processing styles, and stress responses. While this can create community, it can also obscure nuance if we do not reflect deeply on what drives these expanding categories and how context and meaning shape our understanding of difference.

Photo by Allef Vinicius on Unsplash

High Sensitivity as a Temperamental Trait

High Sensitivity, or Sensory Processing Sensitivity (SPS), is a temperamental trait found in approximately 20 to 30% of the population (Aron & Aron, 1997; Lionetti et al., 2018). SPS is characterised by:

• deep cognitive processing

• heightened empathy

• strong emotional responsivity

• sensitivity to subtle stimuli

• a reflective, cautious “pause-to-check” behavioural pattern (Aron et al., 2012)

SPS is not a disorder and is not listed in the DSM-5 (American Psychiatric Association, 2013). It appears in over 100 species, suggesting an evolutionary purpose, as a minority of individuals with heightened attunement enhances group survival (Aron & Aron, 1997; Wolf et al., 2008). As an HSP, you may feel deeply, reflect deeply, and perceive subtle cues others miss, and these are markers of a biologically sensitive nervous system, not signs of pathology.

Holding the Overlap and the Distinction Together

Sensitivity, autism, ADHD and other labels all exist on a continuum, and it is possible to sit across several overlapping dimensions of each. However, the distinctions are also real. Neuroimaging consistently suggests that HSPs and autistic individuals differ in how their brains respond to social and emotional stimuli, with HSPs showing heightened activation in empathy, reward and self-other processing networks (Acevedo et al., 2018), while autism is characterised by broader differences in social communication, reciprocity, restricted interests and patterns of sensory processing. In other words, sensitivity and autism belong to a broader landscape of neurobiological variation in which traits can cluster or correlate and also arise from distinct underlying processes - this matters for how a person is understood and supported.

Understanding ADHD in Relation to Sensitivity

Attention-Deficit/Hyperactivity Disorder (ADHD) is considered to be a neurodevelopmental condition recognised in both the DSM-5 (American Psychiatric Association, 2013) and the ICD-11 (World Health Organization, 2022), characterised by persistent patterns of inattention, hyperactivity, and impulsivity that emerge in childhood and frequently continue into adulthood. It is understood to involve differences in attention regulation, executive functioning, and the modulation of arousal, meaning that focus, working memory, organisation, and the capacity to sustain or shift attention can all be affected in ways that vary considerably from one person to the next. Although it is often described in terms of difficulty, ADHD also brings recognisable strengths, including creativity, hyperfocus on areas of genuine interest, spontaneity, and a capacity for nonlinear thinking, and its expression is profoundly shaped by environment, demands, and context rather than being fixed or uniform.

Recent research is showing us that the relationship between SPS and ADHD is more layered than a simple distinction allows. A growing body of empirical work points to measurable overlap between the two.

Panagiotidi, Overton and Stafford (2020) were among the first to examine the relationship between SPS and ADHD traits. Their work found a significant positive correlation between ADHD traits and HSP Scale scores, suggesting that sensitivity and ADHD-related characteristics tend to co-occur across the general population rather than being strictly separate categories.

Building on this, Schippers and colleagues (2024, 2025) conducted a series of studies on the relationship between ADHD and sensitivity. In a general population sample of nearly 700 people, they found that individuals with more ADHD characteristics also scored higher on a questionnaire measuring high sensitivity. This pattern held for both higher inattention and higher hyperactivity, and a smaller subgroup of participants with a formal ADHD diagnosis scored higher on the sensitivity measure than those without ADHD.

More recently, Greven and colleagues (2025) have proposed that the brains of high SPS individuals consistently assign greater precision to incoming sensory signals. This predictive processing model offers a theoretical bridge between SPS and ADHD while also helping to articulate where their underlying mechanisms diverge.

A 2025 review (Jurek et al., 2025) similarly concluded that individuals with ADHD show significantly higher sensory sensitivity, sensory avoidance, sensory seeking and low sensory registration compared to controls, and the authors explicitly raise the question of how this sensory profile relates to SPS.

What the Research Does and Doesn’t Tell Us

Taken together, this research supports several important conclusions, and I would invite you to hold them all at once rather than choosing between them.

First, it seems SPS and ADHD share measurable overlap (Greven et al., 2019; Schippers et al., 2025). They are correlated in the general population, and they can absolutely co-occur in the same person. However, SPS is associated specifically with heightened sensory sensitivity, whereas ADHD can involve both hyper and hypo-sensitivity. HSPs tend toward depth of processing and reflective decision-making, while ADHD is characterised by differences in attention regulation and executive function. The mechanisms appear to be related but not identical. Again, it seems sensitivity and ADHD belong to a broader landscape of neurobiological variation in which traits cluster, correlate, and sometimes converge, while still arising from partly distinct underlying processes.

Photo by Allef Vinicius on Unsplash

The Rise of AuDHD and the Complexity of Labels

The term AuDHD has grown rapidly through online communities and is not itself a formal diagnostic category, however, it reflects the lived experience of many people who meet criteria for both autism and ADHD. For many people, finding this language has been genuinely clarifying, offering a sense of recognition and belonging that formal systems have often been slow to provide, and that recognition deserves to be honoured. At the same time, the popularity of the term has sometimes led to a wide range of behaviours being grouped together quite quickly, and there can be value in pausing to ask what any given behaviour is expressing for that particular person.

Behaviours such as stimming are a meaningful and valid part of many autistic and ADHD lives, and they can also, for some people, be shaped by anxiety, stress, or the physiological need to discharge excess nervous-system energy. None of these possibilities cancels out the others, and naming them is not a way of explaining anyone’s neurodivergence away; it is simply an invitation to stay curious about the role that environment and context play in how our nervous systems express themselves.

This is also where the recent research becomes especially relevant. If SPS, ADHD and autistic traits all share dimensions of sensory reactivity and overstimulation, then we cannot assume that a person who feels overwhelmed by stimuli necessarily fits one box. They may sit on multiple overlapping continua, and the most useful question is not “which label am I” but “what is my nervous system actually doing, in what context, and what does it need”.

The Power of Context

Current research in neuroplasticity and epigenetics shows that nervous systems are not fixed but malleable, shaped moment to moment by environment, relationship, and experience. Daniel Siegel describes humans as “verb-like states” continually evolving rather than static entities. This means that diagnostic categories do not necessarily capture the full picture of a person’s lived reality.

Understanding yourself through a sensitive, biopsychosocial lens allows space for transformation. It reminds you that behaviours are not destiny, they are often adaptations.

Understanding, Not Fixing

I believe deeply that all lived experiences hold beauty, strength, and intelligence and yet suffering within these experiences is also real. The goal is not to fix anyone, but to understand what drives distress so we can reduce unnecessary suffering and support individuals in meaningful ways.

Many people find diagnoses like AuDHD validating, and that is completely valid. Others find themselves overwhelmed by labels. My aim is neither to reinforce nor deny identity terms, but to encourage deeper exploration, more nuance, and greater compassion.

Why Distinguishing HSP, Autism and ADHD Matters

Clarity matters because:

• people deserve the right support

• misdiagnosis can obscure underlying needs

• people deserve accurate, evidence-based understanding

• nuance helps reduce shame and increase empowerment

Being highly sensitive does not mean you are autistic, and being autistic does not mean you are highly sensitive.

Having ADHD does not mean you are highly sensitive, and being highly sensitive does not mean you have ADHD.

And yet the research is increasingly clear that these traits overlap, they are correlated, they exist on overlapping spectra, and some people genuinely sit at the intersection of more than one. All experiences are valid, and all deserve to be understood with care.

Moving Forward with Respect and Empowerment

Whatever you identify or don’t identify as, you deserve spaces where you are not pathologised but seen, supported, and celebrated. Your nervous system tells a story of adaptation, connection, and complexity, and your journey deserves to be held with understanding and respect.

References

Acevedo, B. P., Aron, E. N., Pospos, S., & Jessen, D. (2018). The functional highly sensitive brain: A review of the brain circuits underlying sensory processing sensitivity and seemingly related disorders. Philosophical Transactions of the Royal Society B, 373(1744), 20170161.

American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.).

Aron, E. N., & Aron, A. (1997). Sensory-processing sensitivity and its relation to introversion and emotionality. Journal of Personality and Social Psychology, 73, 345–368.

Aron, E. N., Aron, A., & Jagiellowicz, J. (2012). Sensory processing sensitivity: A review in the light of the evolution of biological responsivity. Personality and Social Psychology Review, 16, 262–282.

Greven, C. U., Lionetti, F., Booth, C., Aron, E. N., Fox, E., Schendan, H. E., Pluess, M., Bruining, H., Acevedo, B., Bijttebier, P., & Homberg, J. (2019). Sensory processing sensitivity in the context of environmental sensitivity: A critical review and development of research agenda. Neuroscience and Biobehavioral Reviews, 98, 287–305.

Greven, C. U., et al. (2025). Sensory processing sensitivity: Theory, evidence, and directions. Trends in Cognitive Sciences. (Advance online publication; formally published 2026, 30(6), 530–545.)

Jurek, L., Duchier, A., Gauld, C., et al. (2025). Sensory processing in individuals with attention-deficit/hyperactivity disorder compared with control populations: A systematic review and meta-analysis. Journal of the American Academy of Child & Adolescent Psychiatry. Advance online publication. https://doi.org/10.1016/j.jaac.2025.02.019

Lionetti, F., Aron, A., Aron, E. N., Burns, G. L., Jagiellowicz, J., & Pluess, M. (2018). Dandelions, tulips and orchids: Evidence for the existence of low-sensitive, medium-sensitive and high-sensitive individuals. Translational Psychiatry, 8(1), 24.

Panagiotidi, M., Overton, P. G., & Stafford, T. (2020). The relationship between sensory processing sensitivity and attention deficit hyperactivity disorder traits: A spectrum approach. Psychiatry Research, 293, 113477.

Schippers, L. M., Horstman, L. I., van de Velde, H., Pereira, R. R., Zinkstok, J., Mostert, J. C., Greven, C. U., & Hoogman, M. (2024). Associations between ADHD traits and self-reported strengths in the general population. Comprehensive Psychiatry, 130, 152461.

Schippers, L. M., Hoogman, M., & Greven, C. U. (2025). Sensory processing sensitivity and the association with attention-deficit/hyperactivity disorder (ADHD) traits, and ADHD-related strengths in the general population. Current Research in Behavioral Sciences, 9, 100193. https://doi.org/10.1016/j.crbeha.2025.100193

Wolf, M., van Doorn, G. S., & Weissing, F. J. (2008). Evolutionary emergence of responsive and unresponsive personalities. Proceedings of the National Academy of Sciences, 105(41), 15825–15830.

World Health Organization. (2022). International Classification of Diseases, 11th Revision (ICD-11).