Neurodiversity: autism, ADHD and thinking differently

What 'neurodiversity' actually means

Neurodiversity is, strictly, a description: human brains vary, and conditions such as autism, ADHD, dyslexia, dyspraxia and Tourette's are part of that natural variation rather than uniform errors. The neurodiversity movement, which grew out of autistic self-advocacy from the 1990s onward, takes that description and adds a political and ethical claim: that this variation deserves accommodation and respect, not only cure-seeking or suppression.

This does not mean the movement claims neurodivergent conditions never cause difficulty. Many autistic and ADHD people experience real, sometimes severe, challenges with sensory overload, executive function, communication or independent living. The neurodiversity framing argues that support should focus on reducing unnecessary barriers and distress, rather than trying to make someone appear 'normal' for its own sake.

Diagnosis, and who gets missed

UK autism and ADHD assessment services have long, and in many areas worsening, waiting lists, both for children and adults. Diagnostic criteria and clinical tools were historically developed by observing hyperactive boys (for ADHD) and boys with obvious social differences (for autism), which means many girls, women and people who mask their traits went undiagnosed for decades. It is now common for adults, including many women, to receive an autism or ADHD diagnosis in their thirties, forties or later, sometimes after their own child is diagnosed first.

A late diagnosis often brings relief and a new framework for understanding a lifetime of experiences, alongside grief for years spent without appropriate support or understanding.

A diagnosis at forty does not create a new condition. It gives a name to one that was always there.

Where the law sits

Autism and ADHD can both meet the legal definition of disability under the Equality Act 2010 (or the equivalent Northern Ireland legislation) where the condition has a substantial and long-term adverse effect on someone's ability to carry out normal day-to-day activities. This is not automatic; it depends on individual impact, not diagnosis alone. Where it does apply, employers, schools, colleges and service providers have a duty to make reasonable adjustments.

• Written instructions alongside verbal ones, to reduce reliance on working memory.
• Permission to use noise-cancelling headphones or take sensory breaks.
• Flexible or later start times, or the option to work from a quieter space.
• Extra processing time in meetings, exams or assessments.
• Clear, literal communication rather than reliance on unstated social rules.

Common misunderstandings

Autism is often wrongly assumed to mean a lack of empathy or a lack of interest in other people; many autistic people feel empathy intensely but express or communicate it differently from non-autistic norms. ADHD is often reduced to 'can't sit still', which misses inattentive presentations that look more like daydreaming, disorganisation or difficulty starting tasks, especially in adults and in girls, who are frequently missed by school-based ADHD screening built around visible hyperactivity.

Both conditions can coexist with each other and with other conditions such as dyslexia, dyspraxia and anxiety, a pattern sometimes described as being 'AuDHD' or having overlapping neurodivergent traits.

Language: identity-first and person-first

Many autistic adults and their organisations, including the National Autistic Society's community consultations, favour identity-first language ('autistic person') over person-first language ('person with autism'), on the grounds that autism is an integral part of identity rather than an add-on. Preferences vary by individual and by generation, and by condition — ADHD language conventions differ somewhat from autism ones. The safest general approach in professional or public writing is to ask the individual or community in question, and to accept that no single choice will please everyone.

Key takeaways

• Neurodiversity describes natural variation in brain function; the neurodiversity movement argues this variation should be respected, not only treated.
• Autism and ADHD are both covered by the Equality Act 2010 where they have a substantial, long-term effect on daily activities.
• Late diagnosis, especially in women and girls, is common because diagnostic tools were historically built around how autism presents in boys.
• Reasonable adjustments at work or school (clear instructions, quiet space, flexible deadlines) often cost little and help far more people than are formally diagnosed.
• Not every autistic or ADHD person embraces every part of the neurodiversity framing; there is genuine internal debate, particularly around severe support needs.

Further reading

• Autism (National Autistic Society)
• ADHD information (ADHD Foundation)
• Neurodiversity at work (ACAS)