Some families notice patterns. A child who can spend six hours building a complex Lego structure but cannot remember to bring a permission slip home. An adult who performs brilliantly under deadline pressure but has never successfully paid a bill on time. A parent who reads about ADHD in their child and recognises, for the first time, their own lifelong struggles.

These patterns are common. Current estimates suggest that up to 20 percent of the population is neurodivergent. That is one in five people.

The terms used to describe these patterns have changed rapidly in recent years. So has the science. This article provides an overview of what neurodivergence means, where the concept comes from, and what families need to know.

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Neurodiversity, Neurotypical, Neurodivergent: A Vocabulary

Neurodiversity refers to the full range of human brain types within any population. The term was coined in the late 1990s by Australian sociologist Judy Singer, an autistic advocate, to describe what she called the “infinite variation in neurocognitive functioning within our species.”

Just as biodiversity describes variation across plant and animal life, neurodiversity describes natural variation in human cognition, learning, and behaviour. This includes everyone, not only those who think differently.

Neurotypical describes the dominant neurotype in a given population. Neurotypical individuals show cognitive and behavioural patterns that are statistically common within their cultural context. The term is descriptive, not evaluative.

Neurodivergent (or neurodivergence) is an umbrella term for individuals whose neurotype differs from the dominant one. In clinical terms, this includes people with diagnoses historically called neurodevelopmental disorders (NDDs): autism, ADHD, dyslexia, dyspraxia (developmental coordination disorder), and tic disorders including Tourette syndrome.

A note on the word “disorder.” Heritability estimates for autism and ADHD hover around 80 percent (Astle et al., 2022). Conditions that run this strongly in families are not easily described as “errors” in development. Many researchers and neurodivergent individuals therefore prefer terms such as “differences” or “difficulties” over “disorders.” The debate is ongoing and consequential.

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Why the Language Change Matters

The traditional medical model describes autism, ADHD, and dyslexia using pathologising language: disorder, deficit, disturbance, limited capability. This language focuses exclusively on what deviates from a normative standard.

Neuro-affirmative language takes a different approach. It acknowledges that neurodivergent individuals typically show both strengths and challenges—a pattern often visualised as a “spiky profile.”

Examples are well-documented:

• Autistic individuals often show exceptional attention to detail and specialised skills in pattern recognition, music, or computation.

• Individuals with dyslexia frequently demonstrate strong visuo-spatial reasoning and practical problem-solving abilities.

• Individuals with ADHD may excel in high-pressure environments and show high levels of creativity and innovative thinking.

Using the term “difference” rather than “disorder” does not deny that neurodivergent people experience genuine functional impairment. Difficulty managing daily life across home, school, or work is a key reason families seek assessment. But the reframing shifts the clinical question from “What is wrong with this person?” to “What does this person need to function well?”

Research also suggests that language shapes self-concept. Children who hear themselves described as “disordered” may internalise different narratives than children who hear themselves described as “differently wired.” The choice of words is not merely semantic.

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The Transdiagnostic Revolution

One of the most significant recent developments in the study of neurodevelopmental conditions is the transdiagnostic framework.

Historically, diagnostic systems such as the DSM-5 treated autism, ADHD, and dyslexia as discrete categories—neat boxes with clear boundaries. The transdiagnostic perspective argues that these boundaries do not reflect biological or clinical reality (Astle et al., 2022).

Evidence includes:

• Genetic overlap. The same genetic variants are associated with multiple neurodevelopmental conditions.

• Cognitive overlap. Working memory deficits appear in both autism and ADHD. Processing speed difficulties appear across several conditions.

• Clinical overlap. Most individuals who meet criteria for one neurodivergent condition also show clinically significant traits of another.

The practical implication is straightforward. If a family member has one neurodivergent diagnosis, the probability of traits from other conditions is high. A thorough assessment will therefore examine attention, language, motor skills, sensory processing, executive function, and social communication—not just a single diagnostic label.

Astle and colleagues (2022) conclude that the categorical approach has outlived its usefulness and that transdiagnostic, dimensional models better match the data.

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The Spiky Profile

The concept of the “spiky profile” offers a useful visual metaphor.

Imagine a radar chart with axes representing cognitive domains: language, motor skills, executive function, memory, sensory perception, social communication, and attention.

A neurotypical profile typically appears relatively even across these domains—moderate scores without extreme highs or lows.

A neurodivergent profile is “spiky.” It shows peaks (areas of significant strength) and troughs (areas of relative difficulty). The neurodivergent population also shows considerably more variability between individuals than the neurotypical population. Two people with the same diagnosis may have entirely different spiky profiles.

For families, the spiky profile explains otherwise puzzling patterns. A child may perform advanced calculations in their head but cannot tie their shoes. An adult may write elegant prose but cannot estimate how long a task will take. These are not signs of laziness or inconsistency. They are characteristic features of neurodivergent cognitive organisation.

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Heritability and Family Patterns

Neurodivergence runs in families. Formal heritability estimates for ADHD and autism are approximately 80 percent (Astle et al., 2022).

Common patterns include:

• A parent who recognises their own childhood difficulties during their child’s diagnostic assessment.

• A parent who does not perceive their child’s behaviour as unusual because it mirrors their own.

• A grandparent, sibling, or cousin with a diagnosed or suspected neurodivergent condition.

For clinicians, family history is a relevant diagnostic clue. For families, understanding heritability can explain why multiple members share similar traits. It is not unusual for an adult to receive their own diagnosis only after their child is assessed.

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Risks of Unrecognised Neurodivergence

When neurodivergence goes unrecognised and unsupported, several outcomes are statistically more likely. These include educational underachievement, employment instability, relationship difficulties, and higher rates of anxiety, depression, and suicidality (Astle et al., 2022).

Crucially, these outcomes are not inevitable consequences of being neurodivergent. They are associated with lack of recognition, lack of appropriate support, and environments designed without neurodivergent needs in mind. Early recognition and appropriate accommodations are associated with significantly better outcomes.

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Physical Health: Beyond the Brain

Neurodivergence is not confined to cognition and behaviour. It is associated with several physical health conditions, including:

• Hypermobility and Ehlers-Danlos syndromes

• Dysautonomia, including postural tachycardia syndrome (PoTS)

• Epilepsy

• Chronic pain conditions

• Gastrointestinal disorders, including irritable bowel syndrome

• Metabolic conditions, including obesity and vitamin deficiencies

A recognised clinical phenomenon is “diagnostic overshadowing,” where physical symptoms are attributed to neurodivergence or mental health issues rather than investigated independently. Families should be aware that physical complaints from neurodivergent family members warrant the same thorough evaluation as anyone else’s.

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Self-Diagnosis: Benefits and Risks

Public awareness of neurodivergence has grown substantially, including through social media and online content. Many people now identify as neurodivergent based on self-assessment.

David and Deeley (2024) outline several considerations regarding self-diagnosis in neuropsychiatry. Symptoms such as poor concentration, social anxiety, or emotional dysregulation can have multiple causes, including thyroid disorders, bipolar spectrum conditions, or trauma responses. A self-diagnosis of neurodivergence may lead an individual to attribute all difficulties to that framework and miss an alternative, treatable condition.

Self-diagnosis also carries the risk of reinforcing maladaptive patterns or delaying effective intervention. However, the authors do not dismiss the value of self-identification. They note that self-identification is a reasonable starting point for a conversation with a healthcare professional—not an endpoint (David & Deeley, 2024).

For families considering formal assessment, the typical pathway includes a GP referral, screening questionnaires (such as the AQ-10 for autism or the ASRS for ADHD), and referral to a specialist diagnostic service. Waiting times vary considerably by region.

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Private Assessment and the Shared Care Problem

NHS waiting lists for neurodevelopmental assessments in the UK can extend to years. Some families choose private assessment as an alternative. This creates a specific problem.

Leaver and Müller-Sedgwick (2022) describe a “diagnostic gap.” A patient receives a private diagnosis and, in the case of ADHD, a prescription for a controlled medication. They then ask their NHS GP to take over prescribing under a shared care arrangement. The GP, who had no role in the assessment, faces an impossible position: decline and leave the patient without continuity, or accept responsibility for a diagnosis they did not make.

The British Medical Association does not recommend shared care with private providers unless those providers also deliver commissioned NHS services. However, blanket refusals are difficult to justify when patients have no timely NHS alternative. Leaver and Müller-Sedgwick (2022) conclude that the current situation is “untenable” and that neurodevelopmental conditions “deserve better.”

Families considering private assessment should ask providers directly whether they have a shared care protocol acceptable to local NHS GPs before proceeding.

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Summary

Neurodivergence is common, heritable, and associated with both strengths and challenges. The language used to describe it has shifted toward neuro-affirmative terms such as “difference” rather than “disorder.” The transdiagnostic revolution in research suggests that rigid categorical boundaries between autism, ADHD, and other conditions do not reflect biological reality (Astle et al., 2022). Self-diagnosis has both benefits and risks, and families should be aware of the latter (David & Deeley, 2024). For those seeking assessment, private pathways create specific challenges for ongoing care within publicly funded systems (Leaver & Müller-Sedgwick, 2022).

None of this changes the fundamental fact: neurodivergence is a form of human variation, not a defect. Families who understand this are better positioned to advocate effectively.