By Dr Daniel S. Cohen · Updated: 26 April 2026
Summary
ADHD (Attention-Deficit / Hyperactivity Disorder) is one of the most frequent neurodevelopmental disorders in childhood and adolescence. A meta-analysis of 179 studies places its global prevalence at around 7.2 %, and the average age of diagnosis is around 7 years. It is more visible in boys —with a boys-to-girls ratio of roughly 2:1— because boys tend to show more hyperactivity and impulsivity, while girls tend to present more inattentive profiles that go unnoticed for years.
Diagnosing it accurately and early is not a minor detail: untreated ADHD is associated with poorer academic performance, family and social conflict, increased risk of comorbidities in adolescence (depression, disruptive behaviour, substance use) and a high probability of persistence into adulthood.
What is ADHD in children and adolescents
ADHD is a heterogeneous syndrome of neurodevelopment whose core symptoms are attention deficit, hyperactivity and impulsivity. These symptoms are excessive for the child’s developmental age, appear in more than one setting (home, school, leisure) and produce real functional impairment.
Unlike other developmental concerns, ADHD symptoms decrease in novel, organised and interesting situations, and worsen in group settings or with monotonous tasks. This fluctuation —the child in front of a screen is not the same as the child in a maths class— often confuses families and educators.
Neurobiologically, ADHD is associated with a dysfunction of prefrontal dopaminergic and noradrenergic circuits, which are involved in attentional networks, inhibitory control and emotional regulation. It is not a problem of upbringing, willpower or effort: it is a different mode of brain functioning, well-characterised clinically.
Clinical presentations
The DSM-5-TR distinguishes three presentations of ADHD, which are not rigid categories and may shift over the course of a child’s development:
- Predominantly inattentive presentation. Inattention symptoms predominate: distractibility, careless mistakes, difficulty sustaining cognitive effort, forgetfulness. It is the most common presentation in girls and the one most frequently missed in childhood, because these children are typically quiet in the classroom and do not produce visible disruption.
- Predominantly hyperactive-impulsive presentation. Motor restlessness and impulsivity predominate, with fewer clear inattentive symptoms. It is more common in preschool age and in boys, and is usually detected early through disruptive behaviour at school and at home.
- Combined presentation. Combines sufficient symptoms of both inattention and hyperactivity-impulsivity. It is the most frequent presentation in school-age children.
These presentations are not fixed labels: a child with combined presentation in childhood may evolve into a predominantly inattentive presentation in adolescence, when motor hyperactivity decreases and attention deficit persists.
Signs by age
The clinical presentation of ADHD changes according to the developmental stage.
Preschool (3-5 years). Motor hyperactivity is the most visible feature: children who are “unstoppable”, climb in inappropriate places, do not finish games, become frustrated easily, break objects unintentionally. Impulsivity leads to repeated domestic accidents. Inattention is hard to assess at this age because sustained attention is not yet developed.
School age (6-12 years). This is the stage at which most diagnoses are made. Inattention becomes evident: careless mistakes, unfinished tasks, difficulty following long instructions, loss of school materials. Hyperactivity translates into getting up from one’s seat, talking excessively, not waiting one’s turn. Impulsivity generates conflicts with peers, repeated warnings and, in some cases, disciplinary sanctions. It is common for academic performance to fall below the child’s actual capacity.
Adolescence (12-18 years). Motor hyperactivity decreases and turns into internal restlessness. Inattention persists as the most enduring symptom: difficulty organising long pieces of work, procrastination, forgetfulness, low academic performance that contrasts with intellectual capacity. New risks emerge: substance use, risk-taking behaviour, marked family conflict, low self-esteem and, frequently, associated depressive or anxious symptoms.
The role of the school
The school is, alongside the family, the most relevant observer of the clinical picture. Teachers see the child for several hours a day in a structured environment, with demanding tasks and compared with a peer group. A substantial proportion of diagnoses arrive in consultation after a teacher’s comment or a school psychoeducational report.
Coordination with the school’s psychoeducational team —whether it is a public, semi-private, private or international school, such as the Liceo Francés, the British Council School, the International College Spain (ICS) or the American School of Madrid— is part of the routine clinical follow-up of ADHD in children and adolescents.
Coordinated school intervention —reasonable accommodations in assessment, classroom placement, task fragmentation, organisational support— is part of the treatment of ADHD and often has as much impact as medical or psychotherapeutic interventions.
Frequent comorbidities
ADHD in children and adolescents rarely comes alone. Comorbidities shift with age:
At school age:
- Language and learning disorders (dyslexia, dyscalculia).
- Oppositional defiant disorder.
- Anxiety disorders.
- Tics.
During the transition to adolescence:
- Depressive disorders.
- More severe conduct disorders.
In adolescence:
- Problematic substance use.
- Eating disorders (particularly bulimia and binge eating disorder).
- Onset of dysfunctional personality traits.
- In girls: predominance of emotional disorders and learning difficulties, with fewer visible behavioural problems.
Identifying and treating these comorbidities is as important as the principal ADHD diagnosis.
How evaluation works in consultation
The diagnosis of ADHD is clinical. It is established through:
- A detailed interview with the parents, exploring the child’s development, symptoms, family context and impact across settings.
- An interview with the child or adolescent, adapted to their age and developmental level.
- Information from the school (teacher’s report, psychoeducational observation, academic records).
- Physical examination: weight, height, blood pressure and screening for associated syndromes (fetal alcohol syndrome, Fragile X, among others).
- Standardised questionnaires validated for parents and teachers, as a support for clinical assessment and never as a stand-alone diagnosis.
- Complementary neuropsychological assessment, particularly useful in cases of diagnostic uncertainty, complex comorbidities or a dissociation between capacity and performance.
There is no single biological test (blood work, MRI, genetic) that diagnoses ADHD on its own. The evaluation is carried out by a child and adolescent psychiatrist or a clinical team experienced in the disorder, ideally coordinated with the family paediatrician and with the school’s psychoeducational team.
Treatment
Treatment of ADHD in children and adolescents is multimodal. Three pillars work in parallel:
- Psychoeducation for parents and child. Understanding what ADHD is, how it affects the child and which tools exist is the foundation of everything else.
- Behavioural and psychotherapeutic intervention. Parent training in management strategies, cognitive-behavioural therapy with the child, work on executive function, emotional regulation and self-esteem.
- Pharmacological treatment, when necessary. Pharmacological treatments for ADHD are authorised in Spain from age 6 and include stimulants (methylphenidate and lisdexamfetamine) and non-stimulants (atomoxetine and guanfacine). Methylphenidate is the first-line medication in most cases, with documented efficacy of 60-75 % in symptom reduction. The choice, dose and duration are individualised and always under the prescription and supervision of a psychiatrist. Routine clinical monitoring includes weight, height, blood pressure and heart rate.
Added to this is school-based intervention (reasonable accommodations, classroom placement, tutoring, task fragmentation) and, when needed, other complementary disciplines —speech therapy if there is a language disorder, educational psychology if there are learning difficulties, clinical nutrition if appetite is altered by medication.
In clinical practice, coordinated work between psychiatrist, psychotherapist, school and family within the same approach clearly improves outcomes compared with fragmented care.
Why early diagnosis matters
Untreated ADHD has an unfavourable course. Without intervention:
- Between 50 % and 80 % of children retain relevant symptoms in adolescence.
- Between 35 % and 65 % continue to present symptoms in adulthood.
- The risk of academic failure and chronic low self-esteem rises.
- The probability of comorbidity with depression, anxiety, eating disorders and, particularly in adolescence, problematic substance use (alcohol, cannabis, non-prescribed stimulants) increases.
A relevant and often overlooked finding: appropriate pharmacological treatment of ADHD reduces the later risk of substance use in adolescence. Far from “opening the door” to medication misuse, well-indicated treatment is a protective factor.
In the long term, approximately one-third of children with ADHD reach a good adaptation in adulthood. The remaining two-thirds present, to varying degrees, sustained academic, occupational, social or emotional difficulties. Diagnosing early changes that trajectory.
Common myths
- “It’s normal, all children are like that.” What characterises ADHD is the intensity, persistence and functional impact of the clinical picture, not the isolated presence of symptoms.
- “They’ll grow out of it.” False. The majority persist into adolescence and at least one-third into adulthood.
- “Medication numbs them or changes their personality.” False. At appropriate doses, ADHD medications improve attention and regulation, without altering personality or “drugging” the child.
- “Taking stimulants leads to drug use.” False. As mentioned above, the opposite is true: appropriate treatment reduces that risk.
- “It’s just a question of discipline or boundaries.” False. Discipline and boundaries matter, but on their own they do not resolve a neurodevelopmental disorder.
When to consult
Some signs, when sustained for at least 6 months and present in more than one setting (home, school, leisure), tend to point towards an evaluation:
- Motor restlessness or inattention clearly above what is expected for their age.
- Low academic performance that does not match the child’s capacity.
- Repeated complaints from school about behaviour, attention or social interaction.
- Persistent family conflicts around schoolwork, routines or rules.
- Low self-esteem, rapid frustration or associated emotional symptoms.
If you recognise yourselves in several of these situations as a family, it makes sense to discuss it with a psychiatrist experienced in child and adolescent ADHD, ideally embedded in a multidisciplinary team able to coordinate the work with the school, the paediatrician and the family. A full evaluation —whatever the final diagnosis turns out to be— tends to bring substantial clarity to the situation and open clinical options that had not been considered.
Conclusion
ADHD in children and adolescents is common, well identified clinically and better treated than is often believed. The key is not only confirming the diagnosis, but activating early a multimodal approach that combines psychoeducation, behavioural intervention, school support and, when necessary, pharmacological treatment. Doing so on time and in a coordinated way changes the developmental trajectory of the child: it protects academic performance, family and social relationships, and reduces the risk of future comorbidities.
About the author: Dr Daniel S. Cohen. Psychiatrist in Madrid, specialist in child and adolescent psychiatry and adult psychiatry. Medical Director of Clínica Colev. Registration No. 28/4003040 (ICOMEM). Consultations in English, French, Hebrew and Spanish. View professional profile.