ADHD, autism spectrum, and nonverbal learning disorder

Why it matters

ADHD, autism, and NLD affect attention, social communication, and information processing in ways that create distinctive barriers in digital environments. These are neurodevelopmental conditions — present from early development — and they affect a substantial portion of the population. Understanding them helps practitioners design for cognitive diversity. (BoK p. 23)

ADHD

ADHD is a neurodevelopmental condition affecting executive function — the system that controls attention, planning, and impulse regulation. The DSM-5 identifies two symptom clusters, either or both of which may be present: (BoK p. 23)

Inattention symptoms

Difficulty sustaining attention, following detailed instructions, staying organized, avoiding distractions, and completing tasks that require sustained mental effort. Inattention is more prominent in adolescent and adult presentations.

Hyperactivity-impulsivity symptoms

Excessive movement, difficulty staying seated, talking excessively, interrupting, and acting without forethought. These symptoms are more visible in younger children and may decrease with age.

ADHD affects approximately 5–10% of children and 3–5% of adults. Many people have primarily inattentive presentations (formerly called “ADD”) with little hyperactivity.

Accessibility implications

• Cluttered, busy interfaces are highly distracting.
• Long, multi-step processes without clear structure or save points increase the chance of losing track.
• Session timeouts that expire during normal task completion impose unfair time pressure.
• Short, chunked content with clear headings helps users re-orient after distraction.

Autism spectrum disorder

Autism spectrum disorder (ASD) is characterized by two domains of difference, both present from early development: (BoK p. 24)

1. Social communication and interaction: difficulty with back-and-forth conversation, social reciprocity, nonverbal communication (eye contact, gestures), and developing and maintaining relationships.
2. Restricted and repetitive behaviors or interests: insistence on sameness, highly focused interests, repetitive motor mannerisms, and unusual sensory responses (hyper- or hyposensitivity to stimulation).

ASD is a spectrum: individuals vary widely in language ability, intellectual functioning, and need for support. Some autistic people are non-speaking; others are highly verbal.

Accessibility implications for autism

• Predictable, consistent layouts reduce anxiety from unexpected changes.
• Literal, precise language avoids metaphors and idioms that can be confusing.
• Clear instructions without ambiguity.
• Sensory considerations: avoiding autoplay audio or flashing animations.

Nonverbal learning disorder (NLD)

NLD describes a neuropsychological profile with a striking contrast between strong verbal skills and weak nonverbal, spatial, and social processing. People with NLD typically: (BoK p. 24)

• Excel at reading decoding and rote verbal memory.
• Struggle with math (especially geometry and word problems), spatial tasks, and reading social cues.
• Have difficulty with novel, complex, or rapidly changing situations.

The BoK notes that NLD overlaps with the former Asperger syndrome profile. It is not a formal DSM-5 diagnosis but is widely recognized in neuropsychological practice.

Real-world example

An online form for a university program application has 47 fields across 8 pages with no save function. A student with ADHD loses their place repeatedly. A student on the autism spectrum is confused by an ambiguous question phrased as “tell us about yourself.” Both are excluded by design decisions that have nothing to do with the substance of the application — and both are addressable through structural improvements.