ADHD: Beyond the Diagnosis
Attention deficit hyperactivity disorder (ADHD) affects approximately 5% of children and 2.5% of adults worldwide. Long reduced to the image of the disruptive child, ADHD is actually a complex neurodevelopmental disorder that affects attention, inhibition, emotional regulation and executive functions. This article explores the neurobiological foundations of ADHD, its three clinical presentations, current diagnostic criteria and misconceptions to deconstruct.
Attention deficit hyperactivity disorder (ADHD) affects approximately 5% of children and 2.5% of adults worldwide. Long reduced to the image of the disruptive child, ADHD is actually a complex neurodevelopmental disorder that affects attention, inhibition, emotional regulation and executive functions. This article explores the neurobiological foundations of ADHD, its three clinical presentations, current diagnostic criteria and misconceptions to deconstruct.
What Is ADHD?
ADHD (Attention Deficit Hyperactivity Disorder) is a neurodevelopmental disorder recognized by the World Health Organization and classified in the DSM-5. It is characterized by a persistent pattern of inattention, hyperactivity and impulsivity symptoms that do not match the expected developmental level and significantly interfere with social, academic or professional functioning.
ADHD is not a lack of willpower, poor parenting or a behavioral disorder. It is a structural and functional neurological difference that affects how the brain manages attention, motivation and self-regulation. Current research identifies particularities in the dopaminergic network, fronto-striatal circuits and prefrontal cortex.
Neurobiological Foundations
The Dopaminergic System
At the core of ADHD lies a dysfunction of the dopaminergic system. Dopamine, a neurotransmitter essential for motivation, reward and sustained attention, is less available in the synapses of people with ADHD. This particularity explains why they need more intense stimulation to maintain attention — and why they can paradoxically hyperfocus on exciting subjects (Volkow et al., 2009).
The Prefrontal Cortex
Neuroimaging studies show a maturation delay of approximately 3 years in the prefrontal cortex of children with ADHD (Shaw et al., 2007). This cortex is the seat of executive functions: planning, organization, inhibition of impulsive responses, working memory and cognitive flexibility. Its atypical development explains the majority of daily difficulties.
Norepinephrine
Norepinephrine, involved in arousal and vigilance, is also imbalanced in ADHD. This deficit contributes to attentional fluctuations, difficulty filtering irrelevant stimuli and performance variations depending on context.
Genetic Component
ADHD has an estimated heritability of 74% — one of the highest in psychiatry (Faraone et al., 2005). Several genes are involved, particularly those encoding dopamine receptors and transporters (DRD4, DRD5, DAT1). However, genetic expression is modulated by the environment: prenatal factors (tobacco, alcohol, maternal stress), obstetric complications and environmental toxin exposure.
Three Clinical Presentations
Inattentive Presentation (formerly "ADD")
Predominance of inattention without marked hyperactivity. Common in girls and adults, it is often underdiagnosed because it is less visible. Characteristic symptoms:
- Difficulty sustaining attention on long or repetitive tasks
- Frequent forgetfulness in daily life
- Regular loss of objects
- Easy distraction by external stimuli
- Difficulty following instructions through to completion
- Avoidance of tasks requiring sustained mental effort
Hyperactive-Impulsive Presentation
Rarer in isolation, it manifests as:
- Motor restlessness (inability to stay seated, fidgeting)
- Excessive talking
- Difficulty waiting for one's turn
- Interrupting others' conversations or activities
- Impulsive decision-making without measuring consequences
- Inner feeling of constant restlessness (in adults)
Combined Presentation
The most frequent form (approximately 60% of cases), combining inattention and hyperactivity-impulsivity. The intensity of each dimension varies between individuals and may evolve with age — motor hyperactivity tends to decrease in adolescence, replaced by inner restlessness.
Diagnosis
ADHD diagnosis relies on a thorough clinical assessment by a specialist (psychiatrist, developmental pediatrician, neuropsychologist). There is no single biological test. The evaluation includes:
- Detailed clinical interview: developmental history, current symptoms, functional impact
- Standardized questionnaires: ASRS (adults), Conners (children), DIVA 5.0
- Neuropsychological assessment: evaluation of executive functions, attention and working memory
- Differential diagnosis exclusion: anxiety disorders, depression, sleep disorders, thyroid disorders, giftedness
DSM-5 Criteria
At least 6 inattention symptoms and/or 6 hyperactivity-impulsivity symptoms (5 for adults), present for more than 6 months, appearing before age 12, observable in at least two different settings (school/work, home, leisure) and interfering with functioning.
Misconceptions to Deconstruct
| Misconception | Reality |
|---|---|
| "ADHD only exists in children" | 60 to 70% of children with ADHD retain symptoms into adulthood |
| "It's a parenting problem" | It's a neurobiological disorder with 74% heritability |
| "People with ADHD can't concentrate" | They can hyperfocus on exciting subjects |
| "Only boys are affected" | Girls are underdiagnosed (predominantly inattentive form) |
| "ADHD disappears with age" | It evolves but persists — motor hyperactivity decreases, executive difficulties remain |
| "Screens cause ADHD" | ADHD has neurobiological origins, but screens can worsen symptoms |
ADHD Strengths
ADHD is not just about deficits. Many people with ADHD exhibit distinctive strengths:
- Creativity: divergent thinking, ability to make unexpected connections
- Hyperfocus: intense and productive concentration on exciting subjects
- Energy: dynamism, enthusiasm, ability to initiate projects
- Resilience: habit of overcoming obstacles, adaptability
- Quick thinking: non-linear information processing, good crisis management
- Sensitivity: empathy, acute emotional awareness
Support should aim to leverage these strengths while compensating for difficulties, using a person-centered rather than disorder-centered approach.
Medical Disclaimer
The information presented in this article is provided for educational and informational purposes only. It does not constitute medical advice, diagnosis or treatment prescription. ADHD diagnosis must be made by a qualified healthcare professional after a complete assessment. Always consult a specialist before making any changes to your care.
Medical Disclaimer
The information presented in this article is provided for educational and informational purposes only. It does not constitute medical advice, diagnosis, or treatment prescription. If in doubt, always consult your physician or a qualified healthcare professional. The techniques described do not replace conventional medical treatment.