Attention-Deficit / Hyperactivity Disorder (ADHD)
A neurodevelopmental condition affecting attention, impulse control and activity level across the lifespan.
Overview
ADHD is a chronic neurodevelopmental condition characterised by persistent inattention, hyperactivity and/or impulsivity that interferes with functioning. It begins in childhood, often continues into adulthood, and is highly treatable with a combination of behavioural strategies and medication.
Symptoms
- • Inattention: distractibility, poor follow-through, frequent careless mistakes, losing items
- • Hyperactivity: restlessness, fidgeting, difficulty staying seated
- • Impulsivity: interrupting, blurting answers, difficulty waiting turn
- • Time blindness, procrastination, difficulty starting tasks
- • Emotional dysregulation and rejection sensitivity (especially in adults)
Risk factors
- • Family history of ADHD
- • Premature birth or low birth weight
- • Maternal smoking or alcohol use in pregnancy
- • Lead exposure in early childhood
Causes
- • Strong genetic component (heritability ~74%)
- • Differences in dopamine and noradrenaline signalling
- • Prenatal exposures (alcohol, tobacco, prematurity)
- • Not caused by parenting, sugar or screen time
🚨 Red flags — seek urgent care
- • New suicidal thoughts or self-harm
- • Stimulant misuse, diversion or chest pain on medication
- • Severe mood swings, mania or psychosis
When to seek care
- • Symptoms affecting school, work or relationships
- • Suspected ADHD in a child with persistent difficulties
- • Side effects from medication
Diagnosis
- • Clinical assessment by a specialist (psychiatrist, paediatrician or specialist nurse)
- • DSM-5 / ICD-11 criteria: ≥5 (adults) or ≥6 (children) symptoms for ≥6 months, in ≥2 settings
- • Validated rating scales (Conners, ASRS, SNAP-IV) plus collateral history
- • Rule out thyroid disease, sleep apnoea, anaemia, anxiety, depression
Treatment
- • Psychoeducation and environmental adjustments (school/workplace)
- • Cognitive-behavioural therapy and ADHD coaching
- • Stimulants — methylphenidate or lisdexamfetamine (first-line in most guidelines)
- • Non-stimulants — atomoxetine, guanfacine; useful where stimulants are unsuitable
- • Regular monitoring of BP, heart rate, weight and growth (children)
Prevention
- • Avoid alcohol, smoking and recreational drugs in pregnancy
- • Optimise sleep, nutrition and physical activity
- • Early identification reduces long-term impact
Complications
- • Academic underachievement and unemployment
- • Anxiety, depression, substance misuse
- • Driving accidents and risk-taking behaviour
- • Relationship difficulties and low self-esteem
Prognosis
With diagnosis and treatment, most people achieve substantial improvement in function. Symptoms persist into adulthood in around two-thirds of cases, though hyperactivity typically diminishes.
Education & self-care
ADHD is a treatable neurodevelopmental condition. A combination of structure, therapy and (often) medication restores function in the great majority of people.
Frequently asked questions
Can adults develop ADHD?
ADHD begins in childhood, but symptoms are often missed and only recognised in adulthood. Adult-onset ADHD without childhood features is unusual and warrants alternative diagnoses.
Are stimulants addictive?
Under medical supervision at therapeutic doses, stimulants are not addictive and actually reduce substance-misuse risk in people with ADHD.
Does diet cure ADHD?
No diet cures ADHD. A balanced diet supports general brain health; restrictive diets are not recommended.