ADHD: Beyond the Diagnosis

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

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.