What is ADHD – Symptoms, Causes and Digital Inclusion for Those Affected

ADHD – Attention Deficit Hyperactivity Disorder – is one of the most common neurological developmental disorders. It affects children and adolescents as well as adults and manifests as persistent inattention, impulsivity and, in many cases, hyperactivity. Estimates suggest that 5–7% of children and 2–4% of adults worldwide are affected – making ADHD far from a niche condition, but a disorder with broad societal relevance.

ADHD is frequently equated with simple restlessness or a lack of discipline – a widespread misconception. The disorder has demonstrably neurological causes: the brains of those affected regulate neurotransmitters such as dopamine differently from those without ADHD. A related but distinct diagnosis is ADD (Attention Deficit Disorder without hyperactivity), in which motor restlessness is absent while inattention and attentional difficulties are equally pronounced.

For businesses and organisations with digital offerings, ADHD is relevant for a concrete reason: people with ADHD are among those users for whom accessible, low-stimulus, clearly structured websites make a significant difference. WCAG 2.2 explicitly addresses cognitive accessibility – and the German Accessibility Strengthening Act (BFSG) has made WCAG AA legally mandatory for large parts of the digital market since 28 June 2025.

What is ADHD? Definition, Presentation and Prevalence

ADHD is a neurobiological developmental disorder classified under the International Classification of Diseases (ICD-11) as a hyperkinetic disorder. Its presentation is heterogeneous: some individuals primarily show hyperactivity and impulsivity, others suffer mainly from inattention, and others experience all three core symptoms simultaneously. Attentional difficulties are the most stable feature across the lifespan.

The disorder emerges in childhood – symptoms often first become visible at school, when demands on concentration, self-organisation and impulse control increase. In approximately 60% of cases, ADHD persists into adulthood, often with a changed presentation: motor restlessness recedes while inner restlessness, forgetfulness and difficulties working in structured environments become more prominent.

• ✓ Prevalence in children and adolescents: 5–7% worldwide; in Germany, ADHD is one of the most common diagnoses in childhood and adolescence.
• ✓ Prevalence in adults: 2–4% of adults live with ADHD – many without a formal diagnosis.
• ✓ Gender differences: ADHD is diagnosed significantly more often in boys; in girls, the inattentive type predominates, which is less conspicuous and therefore more frequently overlooked.

ADHD Symptoms in Children, Adolescents and Adults

ADHD symptoms change across the lifespan. What appears in childhood as pronounced motor restlessness and impulsive behaviour at school often manifests more subtly in adulthood – as chronic restlessness, procrastination or difficulties in relationships and at work. Common to all age groups is the attentional difficulty: people with ADHD struggle to regulate attention, either unable to sustain it or becoming completely absorbed in topics that captivate them (hyperfocus).

• ✓ Inattention: Frequent careless mistakes, difficulty completing tasks, easy distraction by external stimuli, forgetfulness in daily life.
• ✓ Hyperactivity: Motor restlessness (fidgeting, leaving seat), difficulty sitting still – particularly pronounced in children at school; in adults often experienced as inner restlessness.
• ✓ Impulsivity: Acting without thinking, difficulty waiting, interrupting others in conversation, impulsive decisions.
• ✓ Impact on key life areas: School and training, work and career, family and relationships, social connections – ADHD affects all central areas of life when left untreated.
• ✓ Co-occurring conditions: Anxiety disorders, depression, reading and writing difficulties, and sleep problems occur at above-average rates in people with ADHD.

Causes and Diagnosis: What is Different in the ADHD Brain

ADHD has no single cause – it involves a complex interplay of genetic and neurobiological factors. Twin studies show a heritability of around 70–80%, making ADHD one of the most strongly genetically influenced mental health conditions. In the brains of those affected, the neural circuits regulating dopamine and noradrenaline are primarily involved – neurotransmitters that are critical for attention control, impulse regulation and working memory.

ADHD is diagnosed clinically by specialist professionals: child and adolescent psychiatrists, neurologists or clinical psychologists. The basis consists of structured interviews, standardised questionnaires, behavioural observations and – for children – reports from school and family. There is no blood test or imaging procedure that proves ADHD alone. Parents play a central role in the diagnostic process for children: their observations from everyday life form an essential part of the clinical assessment.

ADHD Treatment: Therapy, Medication and Everyday Strategies

Effective ADHD treatment is multimodal – combining several approaches tailored to the individual situation of those affected. The goal is not to cure the disorder but to reduce impairment in areas such as school, work and family life, while strengthening personal resources and competencies.

• 1 Behavioural therapy: The cornerstone of any ADHD treatment – helps those affected develop strategies for self-organisation, impulse control and managing everyday challenges.
• 2 Parent training: Parents learn to respond constructively to ADHD-typical behaviours in their children and to establish a supportive structure in daily life.
• 3 School-based support: Reasonable adjustments, structured task-setting and close coordination between school and family reduce the impact of the disorder on educational achievement and social participation.
• 4 Medication: Stimulants such as methylphenidate (Ritalin, Concerta) and amphetamines are well-evidenced and a recognised treatment option for moderate to severe ADHD – always in combination with other measures, never as a standalone therapy.
• 5 Everyday strategies: Regular physical activity, consistent daily routines, reduced stimulation in learning and work environments, and digital tools support those affected in daily life.

ADHD and the Web: How Digital Accessibility Helps Those Affected

For people with ADHD, the digital experience is often overwhelming: stimulus-rich websites with animated banners, confusing navigation, long walls of text without clear headings and competing content elements quickly overload the attentional system. Those affected lose the thread, abandon tasks or leave pages before reaching their goal.

The measures that help people with ADHD align closely with good accessibility practice: clear heading hierarchies, consistent navigation, sufficient white space, no auto-playing animations and a recognisable focus path. WCAG 2.2 addresses exactly these points – for example criterion 2.2.2 (moving content can be paused), 2.4.6 (descriptive headings) and 3.2.3 (consistent navigation).

• ✓ Clear structure: Logical heading hierarchy and consistent navigation help people with ADHD grasp content and maintain orientation.
• ✓ Stimulus reduction: No auto-playing videos, no flashing elements, no pop-ups that destroy focus.
• ✓ Focus mode: Directs attention to the currently relevant content and hides distracting page elements.
• ✓ Short, structured texts: Paragraphs of 3–4 sentences maximum, subheadings every 150–200 words and visual anchors assist reading.

Frequently Asked Questions about ADHD