Overview
ADHD (Attention-Deficit/Hyperactivity Disorder) is a brain-based condition that affects how people pay attention, control impulses, and manage their activity level. It is not a sign of low intelligence or laziness. The brain in ADHD develops differently, particularly in areas that handle planning and self-control.
How common is it?
ADHD affects children and adults. NHS England cites estimated prevalence of around 3-5% in children and 2-3% in adults; estimates vary between populations and methods, and diagnosed cases are not the same as total prevalence.
Causes and risk factors
ADHD arises from differences in brain development and brain chemistry, especially involving dopamine and noradrenaline pathways. Genes play a strong role, but environmental factors can also influence how the condition develops.
Common risk factors
- Family history of ADHD
- Premature birth or low birth weight
- Exposure to lead or alcohol before birth
- Brain injury
- Other developmental and environmental influences are still being studied
Symptoms
- Difficulty staying focused on tasks
- Easily distracted by sights or sounds
- Forgetting instructions or losing things
- Interrupting others mid-conversation
- Fidgeting or inability to sit still
- Acting without thinking of consequences
- Poor time management
When to see a doctor
See a doctor if attention or behaviour problems are consistently affecting school, work, or relationships. A formal assessment is needed for diagnosis since many other conditions can look like ADHD.
Diagnosis
Diagnosis requires a trained specialist's clinical and developmental assessment, including how symptoms affect more than one setting. Information from the person, family or school and rating scales can help, but scales alone do not establish ADHD. Other or coexisting conditions must be considered.
Treatments
Stimulant medication
Stimulants can reduce core ADHD symptoms for some people. UK options include methylphenidate and lisdexamfetamine, chosen and monitored by an ADHD specialist. Benefits and side effects vary; monitoring includes pulse, blood pressure, appetite and growth or weight.
Behavioural therapy
Teaches practical skills for planning, organisation, and impulse control. Particularly helpful for children when parents are also involved in the sessions.
Non-stimulant medication
Atomoxetine is one non-stimulant option when appropriate. Guanfacine is used for selected children and young people; in the UK, use in adults is off-label and needs tertiary specialist advice. Age, other conditions and side effects affect the choice.
Self-care and lifestyle
- Break large tasks into small steps with short breaks between them
- Use timers, alarms, and written checklists rather than relying on memory
- Regular aerobic exercise improves concentration and mood
- Keep a consistent daily routine to reduce decision fatigue
Prevention
There is no proven way to prevent ADHD. Earlier recognition and appropriate support at home, school or work can help manage difficulties and protect wellbeing, without guaranteeing particular outcomes.
Sources for targeted updates
Updated: 24 October 2026. Targeted corrections to frequency, diagnosis, treatment, prevention, risk factors. This update covers the named sections; a full review of the remaining guide is pending.