ADHD: diagnosis, symptoms in children and adults
A child fidgeting in class. An adult forgetting their appointments for the third time this week. Is it really ADHD? Understanding this neurodevelopmental disorder — its types, symptoms at each age, and its diagnosis — is the first step to acting effectively.
1. Definition and types of ADHD
ADHD — Attention Deficit Hyperactivity Disorder — is a neurodevelopmental disorder characterized by a trio of fundamental symptoms: inattention (difficulty maintaining concentration, frequent forgetfulness, disorganization), hyperactivity (need for movement, restlessness, inability to stay still), and impulsivity (acting before thinking, interrupting, making hasty decisions). These three dimensions can combine differently depending on the individuals, leading to the existence of three official clinical presentations.
Inattentive Type (30%)
Predominance of inattention without marked hyperactivity. Often diagnosed later, especially in girls.
Hyperactive-Impulsive Type (5%)
Rare in pure form. Dominant hyperactivity and impulsivity, secondary inattention.
Combined Type (65%)
The most common. Combines all three dimensions: inattention, hyperactivity, and impulsivity.
Neurobiology: why the ADHD brain functions differently
ADHD is not a question of lack of willpower or poor upbringing — it is a neurobiological reality documented by decades of brain imaging. Two main mechanisms are at play. First, a dysregulation of the dopaminergic and noradrenergic systems: these neurotransmitters, essential for motivation, reward, and executive control, do not function optimally in ADHD. Second, an immaturity or underdevelopment of the prefrontal cortex, the brain region responsible for planning, inhibitory control, and organization — with a maturation delay estimated at 3-5 years compared to peers.
🧠 ADHD is not a laziness problem
A metaphor often used by specialists: the ADHD brain has a Formula 1 engine with bicycle brakes. Energy, creativity, and the ability to hyperfocus on exciting topics are often above average — but inhibition, organization, and attention regulation in unstimulating tasks are profoundly impaired. This gap is the source of the paradox "can concentrate for 6 hours on a video game but not 10 minutes on homework".
2. Symptoms of ADHD in children
In children, ADHD often manifests in visible and disruptive ways — which sometimes makes it easier to spot, but also generates misunderstandings from the adults around them. Symptoms must be present before the age of 12, in at least two different contexts (home AND school), and significantly impact daily functioning.
The three dimensions in children
Difficulties with attention at school and at home
The inattentive child frequently loses their belongings (backpack, keys, pens), forgets their homework or the instructions given at home, jumps from one activity to another without finishing any, and is easily distracted by the slightest external stimulus. They do not seem to "listen" even when spoken to directly. These difficulties are not due to a lack of will — they reflect a genuine inability to maintain focus on unstimulating tasks.
The need for movement that cannot be restrained
The hyperactive child cannot sit still — they fidget, get up, run, or climb in situations where it is inappropriate. They talk a lot and loudly, have boundless energy, and constantly seek new stimuli. At home, they may seem always "plugged in," unable to settle down even to watch a movie. This motor hyperactivity tends to decrease in adolescence, often transforming into mental restlessness in adulthood.
Acting before thinking
Impulsivity manifests as frequent interruptions in conversations, difficulty waiting for their turn, responses given before the question is finished, and decisions made without considering the consequences. In class, this often translates into conflicts with peers ("he hit me for no reason") which are actually impulsive reactions to frustrations, not intentionally aggressive behaviors.
Impact and comorbidities in children
ADHD is not limited to the three cardinal symptoms. Its repercussions affect all aspects of the child's life: degraded academic results despite often normal or above-average potential, relational difficulties with peers (impulsivity generates frequent conflicts), and damage to self-esteem (a child who hears "you could do better if you tried harder" dozens of times a day ends up believing they are worthless).
Comorbidities are the rule rather than the exception: 30 to 40% of children with ADHD also have an anxiety disorder, 50% have significant sleep disorders, 30% have an associated learning disorder (dyslexia, dyscalculia), and 20 to 30% present an oppositional defiant disorder (ODD) that can mask the underlying ADHD.
3. Symptoms of ADHD in adults
Adult ADHD is profoundly different in its expression from childhood ADHD — and that is why it often remains undiagnosed. Motor hyperactivity has transformed. Society has forced adults to sit down, be quiet, and "act like others." But the ADHD brain has not changed.
How ADHD reinvents itself in adulthood
Adult inattention: invisible but costly
The adult with ADHD consistently arrives late to meetings, forgets important appointments, starts five projects simultaneously without finishing any, and massively procrastinates on boring tasks until a crisis occurs. Their inbox contains several thousand unread emails. They are creative, enthusiastic about new missions — but routine, follow-up, and administrative rigor represent a colossal effort that their colleagues are often unaware of.
Mental hyperactivity: a brain that never stops
The adult with ADHD does not get bored — they are constantly overwhelmed by thoughts, ideas, and projects that overlap. This constant mental agitation can resemble generalized anxiety and is often misdiagnosed. The difficulty in relaxing, in "just watching a movie without doing anything else," the constant need for stimulation (music + phone + TV at the same time) are manifestations of this internalized hyperactivity.
Adult impulsivity: lasting consequences
Adult impulsivity manifests in compulsive purchases (buying something unnecessary "because it was there"), frequent job changes (quitting a stable position on a whim), relationship conflicts (hurtful responses given "without thinking"), and sometimes risky behaviors. These behaviors are not character flaws — they are the adult translation of the same dysregulation of inhibitory control present from childhood.
I was diagnosed with ADHD at 43, after my son's diagnosis. Looking back on my life in light of this diagnosis — the lost jobs, difficult relationships, abandoned projects — everything suddenly made sense. It wasn't laziness. It was a brain functioning differently, without anyone ever giving me the keys.
4. Diagnosis and tests for ADHD
The diagnosis of ADHD is clinical — there is no blood test or MRI that confirms it. It relies on a multidimensional evaluation combining standardized questionnaires, cognitive tests, and a thorough clinical interview.
Screening questionnaires
| Questionnaire | Population | Duration | Usage |
|---|---|---|---|
| ASRS v1.1 (Adult ADHD Self-Report Scale) | Adults | 5 min | Screening — 6 items, available for free online |
| Conners Rating Scale | Children (parents + teachers) | 15–20 min | 27 to 48 items, pediatric gold standard |
| SNAP-IV | Children | 10 min | 26 items, aligned with DSM-5, multi-informant |
Cognitive tests: objectifying difficulties
Questionnaires provide a subjective picture. Cognitive tests objectify attention difficulties. The CPT (Continuous Performance Test) measures sustained attention, omissions (inattention), and commissions (impulsivity) over 15 to 20 minutes. DYNSEO offers two equivalents accessible for free: the Selective Attention Test (ability to identify targets among distractors) and the Processing Speed Test (reaction time and cognitive efficiency).
The Stroop Test assesses inhibition — naming the color of the ink of a colored word creates a cognitive conflict particularly revealing of the frontal dysfunction of ADHD. The WISC/WAIS (full-scale IQ) often reveals a "sawtooth" profile in ADHD, with a gap between verbal comprehension (often high) and processing speed (often low).
For an initial evaluation accessible immediately, DYNSEO also offers the Non-Medical ADHD Test — a screening tool that assesses symptoms according to DSM-5 criteria and can serve as a basis for discussion with a healthcare professional.
💡 The diagnostic process in practice
The formal diagnosis is made by a psychiatrist, child psychiatrist, or neuropsychologist after an evaluation of 3 to 4 hours. Waiting times are often 2 to 6 months. Starting with DYNSEO's online tests allows for preparation for this consultation with objective data and helps guide the questions to ask.
5. Treatment and solutions
Pharmacological approach
When ADHD is confirmed and severe, medication can transform the patient's life. Methylphenidate (Ritalin, Concerta) is the first-line treatment — it increases the availability of dopamine in the prefrontal cortex and improves attention, inhibition, and organization in 70 to 80% of patients. Amphetamines (Vyvanse, not available in France but used in other countries) are an alternative in case of non-response. Atomoxetine (Strattera) is a non-stimulant used when stimulants are contraindicated or ineffective.
Cognitive behavioral therapy and coaching
CBT (cognitive-behavioral therapy) adapted for ADHD works on time management, organizational strategies, emotional regulation, and positive reinforcement. ADHD coaching — distinct from psychotherapy — focuses on practical daily tools: planners, reminder systems, externalized routines, breaking down complex tasks. These approaches are essential, especially for adults, and yield the best results when combined with medication treatment.
✔ Lifestyle and ADHD: the most accessible levers
- Sleep: 7–10 hours for children, 7–9 hours for adults — lack of sleep dramatically worsens all ADHD symptoms
- Physical exercise: 45–60 min/day of aerobic activity — naturally increases dopamine, reduces hyperactivity, and improves executive functions
- Nutrition: avoid refined sugars (glycemic spike → dopaminergic crash), favor proteins in the morning, omega-3
- Structuring the environment: reduce distractions (clean desk, phone on silent), short and visible task lists
- Educational support: PAP (Personalized Support Plan), extra time on exams, placement at the front of the class
🎯 DYNSEO resources for ADHD
DYNSEO has supported over 5,000 families affected by ADHD and collaborated with over 100 schools to improve inclusion. Its resources cover all stages:
• Non-Medical ADHD Test — free online screening
• Selective Attention Test — objective measurement of abilities
• Training "Supporting a Child with ADHD" — keys and solutions for daily life
• Training "ADHD in Adolescents" — impulsivity and opposition
• Training "ADHD in Adults" — organization and managing impulsivity
FAQ — Frequently Asked Questions about ADHD
What exactly is ADHD?
ADHD is a neurodevelopmental disorder characterized by inattention, hyperactivity, and impulsivity. It is 75% genetic, present from childhood, and persists into adulthood in 60% of cases. It is not a lack of will but a different neurological functioning related to dopamine and norepinephrine.
What are the 3 types of ADHD?
The DSM-5 distinguishes the Inattentive type (30%, often diagnosed late, common in girls), the Hyperactive-Impulsive type (5%, pure rare), and the Combined type (65%, the most common, combining all three dimensions).
Does ADHD disappear in adulthood?
No. It persists in 60 to 70% of cases, although motor hyperactivity decreases. It transforms into mental restlessness in adults. Many are diagnosed only at 30-50 years old, often after their child's diagnosis.
Is ADHD curable?
ADHD is not curable but can be managed very effectively. The combination of medication + behavioral therapy + coaching yields the best results. Lifestyle (sleep, exercise, nutrition) plays a crucial complementary role.
Is ADHD hereditary?
Yes, strongly — heritability of 75%. If a parent is affected, the risk for the child is 40 to 57%. Genes involved in the dopaminergic and noradrenergic systems have been identified.
Girls and ADHD: why is the diagnosis often late?
Girls with ADHD predominantly present the Inattentive type (less visible than boys' hyperactivity) and often develop camouflage strategies. They are diagnosed on average 3 to 5 years later than boys, often after being labeled as "dreamy," "anxious," or "unmotivated."
Conclusion: understanding ADHD is changing the perspective
ADHD is not a character flaw or a parental failure. It is a documented neurological disorder that affects millions of children and adults, often without their knowledge. Making the right diagnosis — and making it early enough — changes life trajectories. Education, kindness, and the right support tools make a significant difference.
Start by objectively assessing your attention capabilities with the free DYNSEO ADHD test, then explore our training to best support the concerned child, adolescent, or adult.