ADHD in children and adults: symptoms, diagnosis and treatment

What is ADHD?

Attention deficit hyperactivity disorder, usually known as ADHD, is a neurodevelopmental condition. This means it is related to the way the brain develops and regulates certain functions from childhood onwards. It can affect attention, impulse control, organisation, motivation and, for some people, activity levels.

The words “attention deficit” and “hyperactivity” do not describe everyone in the same way. Some people are very restless and cannot stay still, whereas others mainly experience inattention. In adults, hyperactivity is sometimes less visible than it is in children. It may appear as a feeling of inner restlessness, difficulty remaining inactive or a constant need to move and keep busy. Clinicians generally distinguish predominantly inattentive, predominantly hyperactive-impulsive and combined presentations. The way these features appear can change with age and circumstances.

ADHD begins in childhood, even when it is only identified much later. A child may have compensated through a highly structured routine, strong academic ability or constant support from people around them. Difficulties may become more noticeable when demands for independence increase, such as during secondary school, university, a first job, parenthood or a period with many competing responsibilities.

How many people are affected?

International studies generally place prevalence at around 5 to 8 children in every 100. For adults, a commonly used estimate is approximately 3 in every 100, although some estimates approach 5 in 100 depending on the definition and population. A global analysis of adult ADHD estimated persistent adult ADHD at 2.58%, while the World Federation of ADHD International Consensus Statement reports approximately 5.9% in young people and 2.5% in adults.

These figures do not mean that ADHD necessarily disappears at adulthood. Symptoms decrease for some people, change form for others or continue to interfere with everyday life. Diagnosis rates also depend on access to care and on whose signs are recognised.

What causes ADHD?

There is no single cause. Heredity plays a major role: ADHD occurs more frequently in some families, and research shows a substantial genetic contribution. This does not mean that one “ADHD gene” determines the condition. Many genetic variations, interacting with one another, influence development.

Premature birth and low birth weight are associated with a higher likelihood of ADHD. Researchers also study certain exposures during pregnancy, including tobacco, alcohol and environmental toxins. Very difficult experiences in early childhood may increase vulnerability, stress and problems with regulation. These are associated factors or risk factors: they do not automatically cause ADHD, and many people with ADHD were not exposed to them. Conversely, screens, sugar or permissive parenting are not considered simple causes. They may influence sleep or behaviour in some situations without creating ADHD.

How does ADHD show up?

ADHD mainly involves two groups of features: inattention and hyperactivity-impulsivity. Their intensity and combination are different for each person.

Inattention may involve:

• regularly losing belongings or forgetting appointments;
• struggling to finish tasks, especially long or repetitive ones;
• moving quickly from one idea to another;
• overlooking details or making careless mistakes;
• appearing not to listen because attention has drifted;
• underestimating how long something will take and starting too late;
• postponing activities that require sustained mental effort;
• difficulty sorting, planning and prioritising.

Hyperactivity and impulsivity may involve:

• moving frequently, leaving one’s seat or handling objects;
• talking a great deal or interrupting;
• answering before a question has been completed;
• finding it difficult to wait;
• making decisions or purchases very quickly;
• constantly looking for stimulation;
• experiencing impatience or an internal sense of restlessness.

In children, these behaviours may be noticed in class, during homework, at mealtimes or in group activities. In adults, they may appear in the management of emails, deadlines, money, household tasks or conversations. A person may also focus very intensely on an interesting activity while finding it extremely hard to begin administrative work. This “hyperfocus” does not contradict ADHD: the difficulty lies primarily in regulating and intentionally directing attention.

People with ADHD sometimes describe strong emotional reactions, rapid frustration or sensitivity to rejection. Such experiences are common but are not, on their own, the central diagnostic criteria. Sleep problems, anxiety, depression, learning disorders or autism may also coexist with ADHD and affect how it presents.

What impact can ADHD have on everyday life?

Impact depends less on the number of symptoms than on their intensity, persistence and the environment. A predictable, supportive setting may reduce difficulties, while change, tiredness or overload may make them more visible.

At school, a child may know the material but miss an instruction, submit incomplete work or be disciplined for repeatedly speaking out of turn. Comments such as “could do better” may gradually create the belief that they are not trying hard enough. Other children go unnoticed because they daydream quietly, compensate extensively or achieve good grades at the cost of considerable exhaustion.

In adulthood, ADHD can complicate prioritisation, deadlines, paperwork and stable routines. At work, someone may be creative and highly responsive in a crisis yet lose track of a long project. In relationships and family life, forgetfulness, interruptions or an uneven division of tasks can be interpreted as a lack of care. Finances, driving, sleep and keeping up with the home may also be affected.

Repeated difficulties can damage self-esteem. After years of being described as distracted, lazy or “too much”, someone may feel ashamed or stop trusting their abilities. Understanding how their attention works can help them view their history more accurately and look for better-suited strategies.

ADHD is not only a list of weaknesses. Some people describe curiosity, enthusiasm, ease with improvisation, creativity or considerable energy when something engages them. These are neither guaranteed symptoms nor universal “superpowers”, but personal qualities that may be easier to express in a suitable environment.

How is ADHD diagnosed?

Diagnosis is based on a comprehensive clinical assessment. For adults, it is generally conducted by a psychiatrist trained in ADHD, sometimes by a neurologist or a specialist team. For children, it may be conducted by a child psychiatrist, paediatrician or specialist paediatric neurologist. A clinical psychologist or neuropsychologist may also contribute to the assessment by conducting interviews and additional tests.

An assessment may include:

1. a detailed interview about childhood, education, work, relationships and health;
2. standardised questionnaires completed by the person and sometimes someone close to them;
3. information from parents, school reports or old records when available;
4. consideration of other possible explanations, such as insufficient sleep, anxiety, depression, trauma, substance use or another neurodevelopmental condition;
5. assessment of coexisting conditions so that support can be planned coherently.

For children, observations from both family and school are particularly useful. For adults, a lack of childhood records does not necessarily prevent assessment: the clinician can reconstruct developmental history from several sources. The NICE recommendations emphasise specialist assessment and state that symptom scales should not be used alone to make a diagnosis.

An online questionnaire can help someone recognise patterns and decide whether a conversation would be useful, but it cannot replace a clinical assessment. You can try our adult ADHD assessment, which follows the ASRS v1.1 method.

What treatments are available for ADHD?

Treatment is personalised. It depends on age, the degree of difficulty, coexisting conditions, preferences and personal goals. It often combines several approaches rather than relying on one solution.

Psychoeducation is an important first step. Understanding ADHD can help identify difficult situations, replace blame with more accurate explanations and select realistic tools. For children, parent support and adjustments at school may be central: short instructions, tasks divided into stages, visible routines, seating that limits distractions, planned breaks and positive reinforcement. The aim is not to eliminate every difference, but to help the child learn and participate in better conditions.

For adults, psychological support can address organisation, procrastination, emotional regulation and negative beliefs built up over many years. Cognitive behavioural therapy adapted for ADHD can provide practical methods for planning, starting tasks and solving problems. Adjustments in education or at work may also be helpful.

Stimulant or non-stimulant medication may be prescribed following a medical assessment. Medication acts on the core symptoms for many people, but the choice, dosage and monitoring need to be individualised. The prescriber considers benefits, side effects, general health and other treatment. Physical activity, sufficiently regular sleep and balanced nutrition support overall health, but do not replace indicated care.

Can ADHD be cured?

ADHD is not usually described as an illness that can be “cured” through a single intervention. It is a lasting neurodevelopmental pattern, although its expression can change considerably. Some children no longer meet every diagnostic criterion as adults; others continue to experience difficulties, sometimes in a different form from childhood.

Substantial improvement is possible. Treatment can reduce symptoms, compensatory strategies can become more effective and a better-suited environment can lessen their impact. The goal is not necessarily to remove every difference. It is to help the person understand their needs, develop autonomy and live with fewer obstacles.

How can someone with ADHD be supported?

Useful support begins with observation rather than judgement. Saying “try harder” rarely makes the next step clearer. A specific, visible instruction divided into manageable parts is much more practical. For children and adults alike, it can help to:

• turn a vague objective into small actions;
• use a shared calendar, reminders or lists placed where they are needed;
• prepare transitions and announce changes;
• schedule breaks and reduce distractions during demanding tasks;
• agree on a fixed place for important belongings;
• offer prompt, concrete and respectful feedback;
• acknowledge effort and strategy, not only outcomes;
• ask the person what actually helps them.

Support does not mean doing everything for someone else. It means developing external structures until certain habits become easier to manage.

Do we all have a little ADHD?

Anyone can lose their keys, procrastinate, interrupt someone or struggle to focus after a poor night’s sleep. These common experiences resemble some ADHD symptoms, but a simple resemblance is not enough. In ADHD, features form a persistent pattern, began during development, occur across several areas of life and cause significant impairment.

This question is now complicated by digital overstimulation. In many Western societies, smartphones bring together work, practical tasks, relationships, news and entertainment. Messages, emails, notifications and constantly renewed content repeatedly compete for attention. Disconnecting becomes difficult when many services depend on a screen and rapid availability has become an everyday expectation.

This accumulation encourages interruptions and frequent switching between tasks. A study of the attentional cost of notifications found that a notification alone can disrupt a demanding task, even when the phone is not checked. Tiredness, stress and insufficient sleep may further intensify this feeling of scattered attention.

Digital overstimulation can therefore produce difficulties that resemble some signs of ADHD without being ADHD itself. To distinguish them, it is important to consider when the difficulties began, whether they were already present in childhood, the situations in which they occur and their practical consequences.

When should you consult a professional?

It may be useful to seek advice when difficulties with attention, impulsivity, restlessness or organisation persist, occur in several situations and interfere with education, work, relationships, finances or self-esteem. For a child, concerns shared by family and school deserve attention. For an adult, a history of interrupted studies, exhaustion from compensating or repeated problems with daily management may also justify an assessment.

A doctor can first consider physical factors, sleep disorders and other possible explanations, then refer to a professional trained in ADHD where appropriate. Bringing a few concrete examples, a timeline of the difficulties and any available childhood information often makes the discussion easier.

Take our adult ADHD assessment

Are you wondering about your attention, organisation or impulsivity? The Yachay adult ADHD assessment contains 18 questions and follows the ASRS v1.1 method. It helps you put recent experiences into perspective and provides an immediate result in your account. If your difficulties are persistent or affect everyday life, the result can be a useful starting point for describing them to a professional.