Paediatrics chapters
ADHD, tics and autism
Three common neurodevelopmental problems of childhood: how ADHD is diagnosed and treated with stimulants, how tics and Tourette syndrome behave, and how autism presents, is screened for and managed.
- ADHD is a persistent pattern of inattention, hyperactivity and impulsivity starting before 12 years, present in two or more settings and causing impairment; it is commoner in boys, highly heritable, and treated with behavioural support plus stimulants (methylphenidate) as first-line drugs.
- Tics are sudden, rapid, non-rhythmic movements or sounds; transient tics are common; Tourette syndrome is multiple motor tics plus at least one vocal tic for over a year, often with ADHD or OCD, and most children need only education.
- Autism shows impaired social interaction, impaired communication and restricted, repetitive behaviour, starting before 3 years; check hearing, look for fragile X, and start early intensive behavioural therapy; drugs treat only associated problems.
On this page
Overview
ADHD, tic disorders and autism are neurodevelopmental disorders: the brain develops differently, usually from genetic causes, and the problems show in behaviour, attention, communication and movement. They often occur together (ADHD with tics, autism with ADHD) and can be confused with each other, with hearing loss, learning disability or family stress. Diagnosis is clinical, based on careful history from parents and school and observation of the child.
Attention deficit hyperactivity disorder (ADHD)
Definition and epidemiology
- A persistent pattern of inattention, hyperactivity and impulsivity beyond what is expected for the child's developmental level.
- Prevalence about 3-7% (Akbar); 5-10% in some studies (Nelson).
- Boys are diagnosed 2-6 times more often. Girls more often have the inattentive type and are diagnosed late.
- Hyperactivity tends to lessen with age; inattention persists. Symptoms continue into adolescence and adulthood in about 60-80%.
Causes
- Genetic: high heritability (about 0.8); first-degree relatives are at higher risk.
- Neurotransmitters: dopamine and noradrenaline pathways in the frontal lobes, basal ganglia (caudate) and cerebellum; brain volume is slightly smaller.
- Prenatal exposure to nicotine or alcohol; brain injury or CNS infection.
- Associations: fragile X, 22q11.2 deletion, neurofibromatosis type 1, intellectual disability.
- Psychosocial stress and chaotic homes make symptoms worse.
Clinical features
| Domain | Typical behaviour |
|---|---|
| Inattention | Careless mistakes, does not seem to listen, does not finish tasks, poor organisation, avoids tasks needing sustained effort, loses things, easily distracted, forgetful |
| Hyperactivity | Fidgets, leaves seat in class, runs and climbs at wrong times, cannot play quietly, "driven by a motor", talks too much |
| Impulsivity | Blurts out answers, cannot wait for a turn, interrupts and intrudes on others |
Diagnosis (DSM-5, as given in Nelson)
- At least 6 symptoms of inattention and/or 6 of hyperactivity-impulsivity (5 from age 17).
- Present for at least 6 months.
- Several symptoms before age 12.
- Present in two or more settings (for example home and school).
- Clear impairment in social, school or work functioning.
- Not better explained by another disorder.
Types: predominantly inattentive, predominantly hyperactive-impulsive, or combined.
Symptoms must be present in more than one setting. A child who is hyperactive only at school or only at home needs another explanation.
A child with ADHD may sit calmly in a quiet clinic room. A normal office examination does not exclude ADHD; rely on parent and teacher rating scales (for example Conners or Vanderbilt).
Assessment and differential diagnosis
- History from parents and teachers, rating scales, school reports.
- Full physical and neurological examination, looking for dysmorphic features.
- Hearing and vision testing.
- Laboratory tests and imaging are not routine; consider thyroid tests or blood lead if suggested.
- Psychometric (IQ) and educational testing for learning problems.
| Rule out or recognise | Examples |
|---|---|
| Normal behaviour for age | Active preschool child |
| Sensory deficits | Hearing or vision loss |
| Medical | Obstructive sleep apnoea, absence seizures, hyperthyroidism, lead poisoning, drugs |
| Developmental | Intellectual disability, learning or language disorder, autism |
| Psychosocial | Abuse, neglect, bullying, family chaos |
Comorbidities (about 50-60%)
- Oppositional defiant and conduct disorder.
- Anxiety and depression.
- Learning disabilities and language disorders.
- Tic disorders; later substance misuse.
Management
Non-drug measures (for all)
- Explain that ADHD is a chronic condition; educate parents and child.
- Behaviour management: structure, routine, consistent responses, positive reinforcement, clear goals.
- School support: classroom changes, daily report cards, small structured classes.
- Social skills training; treat coexisting problems.
Medication
| Group | Drugs | Notes |
|---|---|---|
| Stimulants (first-line) | Methylphenidate, amphetamines (dexamfetamine, lisdexamfetamine) | Most effective; short and long-acting forms; side effects: reduced appetite, sleep disturbance |
| Noradrenaline reuptake inhibitor | Atomoxetine | Non-stimulant; gastrointestinal upset |
| Alpha-2 agonists | Clonidine, guanfacine | Useful when tics or sleep problems coexist; cause sedation |
| Tricyclics | Imipramine (Akbar) | Older option; check ECG (QT) first |
- Non-stimulants are chosen when stimulants fail, when there is a risk of misuse, or when there are tics or sleep problems.
- Screen for heart disease by history and examination before stimulants and monitor heart rate and blood pressure, as a very small risk of sudden cardiac death has been suggested.
Stimulants are first-line and, contrary to parents' fears, properly treated children have a lower, not higher, risk of later drug misuse.
ADHD treatment = "Structure at home, support at school, stimulant if needed."
Outcome
Untreated ADHD leads to school failure, poor self-esteem, difficult relationships and, in adolescence, risky behaviour, drug use and road accidents.
Tic disorders and Tourette syndrome
Definitions
- A tic is a sudden, rapid, recurrent, non-rhythmic movement (motor tic) or sound (vocal or phonic tic). It is involuntary, purposeless and stereotyped, usually involving the face, eyes, neck and shoulders.
- Simple motor tics: eye blinking, nose twitching, neck jerking, shoulder shrugging.
- Complex motor tics: more organised movements such as head shaking, gesturing, jumping.
- Simple vocal tics: throat clearing, sniffing, coughing, grunting.
- Complex vocal tics: words or phrases.
| Type | Features |
|---|---|
| Transient (provisional) tics | Common; last less than a year |
| Chronic motor or vocal tic disorder | Motor or vocal tics for more than a year |
| Tourette syndrome | Multiple motor tics and at least one vocal tic for more than 1 year, starting in childhood (usually before 7 years) |
Course and associations
- Onset usually 4-6 years; worst at 10-12 years; tics wax and wane and change over time (one tic replaced by another).
- Most improve greatly or disappear by late adolescence.
- Family history of tics in more than half.
- Comorbidity in about half of Tourette cases: ADHD and obsessive-compulsive disorder.
- Stimulants can unmask or worsen tics.
- Many children are not troubled by their tics and some are unaware of them.
Families often blame frequent sniffing, throat clearing, coughing or blinking on allergy or eye problems; these may be tics.
Diagnosis
- Clinical. EEG and brain imaging are not routine; reserve them for other neurological signs.
- With a sudden, severe onset, look for a recent infection and consider an autoimmune cause.
- Screen for ADHD and OCD.
Management
- Education of the child, family and school; reduce teasing and stress. Drawing attention to a tic often makes things worse.
- Behavioural therapy: habit reversal training.
- Drugs only for disabling tics. The aim is to reduce tics to a tolerable level, not to remove them.
| Drug | Notes |
|---|---|
| Clonidine, guanfacine (alpha-2 agonists) | Milder option; also help ADHD; sometimes combined with pimozide |
| Dopamine blockers: pimozide, risperidone, haloperidol | Most effective drugs for Tourette syndrome |
Dopamine-blocking neuroleptics (pimozide, risperidone, haloperidol) are the most effective drugs for Tourette syndrome; clonidine is a milder alternative.
Autism spectrum disorder
Definition
Autism spectrum disorder (older term: pervasive developmental disorder) is a lifelong neurodevelopmental disorder with three core areas of difficulty, starting before 3 years:
- Impaired social interaction.
- Impaired communication (language and non-verbal).
- Restricted, repetitive and stereotyped behaviour, interests and activities.
Older classifications listed autism, Asperger syndrome, childhood disintegrative disorder, Rett syndrome and pervasive developmental disorder not otherwise specified.
Epidemiology and causes
- Common: about 1 in 150 children (Akbar), with prevalence figures varying between studies.
- Boys are affected about 5 times more often (except Rett syndrome), but affected girls are often more severely affected.
- No cause is found in 80-90%.
- Genetic: strong family tendency; high concordance in identical twins; siblings have a 2-10% risk.
- A known syndrome is found in 10-20%, especially fragile X syndrome and tuberous sclerosis.
- Other associations: congenital rubella, untreated phenylketonuria, infantile spasms, postnatal CNS infection.
Clinical features
Social interaction
- Poor eye contact; does not respond to name.
- No social smile or delayed smile in infancy.
- Does not point to share interest or bring things to show.
- Prefers to be alone; little interest in other children; lack of imaginative play.
Communication
- Delayed or absent speech; poor use of gestures.
- Echolalia (repeating words), pronoun reversal ("you" for "I"), odd tone.
- Poor understanding of facial expression and body language.
Restricted, repetitive behaviour
- Insistence on sameness; tantrums when routines change.
- Hand flapping, rocking, spinning, head banging.
- Intense interest in parts of objects or narrow topics.
- Unusual responses to sensory input; apparent insensitivity to pain; no fear of danger.
- About 20% have fairly normal early development and then lose skills in the second year (regression).
- Some children have isolated special skills (savant abilities).
Poor eye contact, not turning to name, no social smile, no sharing or pointing, delayed speech and any loss of language or social skills are red flags for autism.
Comparison of the main subtypes
| Feature | Autism | Asperger syndrome | Rett syndrome | Childhood disintegrative disorder |
|---|---|---|---|---|
| Sex | Mainly boys | Mainly boys | Girls (MECP2 gene) | Mainly boys |
| Language | Marked delay | Good vocabulary, poor social use | Lost | Lost after normal development |
| Intellect | Often low | Normal or high | Severe impairment | Severe impairment |
| Key point | Onset before 3 years | Motor clumsiness, narrow interests | Slowing head growth, loss of hand use, hand-wringing | Normal till about 2 years, then marked regression |
Assessment
- Screening for autism at 18 and 24 months (for example the M-CHAT questionnaire); earlier if there are parental concerns or an affected sibling.
- Diagnosis is clinical, by a specialist team.
- Hearing test in every child (deafness can mimic autism).
- Genetic tests: chromosomal analysis and fragile X testing; look for tuberous sclerosis (skin examination).
- Metabolic tests (for example PKU) and tests for congenital infection if indicated.
- EEG if seizures are suspected (abnormal in about 20-25%).
- Psychological testing: non-verbal skills are often better than verbal ones.
Always test hearing in a child with delayed speech who "ignores" people; deafness is a key differential of autism.
Associated problems
- Intellectual disability (up to 80% in older series).
- Epilepsy in about 25%, often starting around puberty.
- ADHD, anxiety, obsessive-compulsive behaviour, sleep problems, constipation.
Management
There is no cure and no drug for the core features. Treatment aims to help the child function as well as possible.
- Early, intensive behavioural therapy (ideally before 3 years), such as applied behavioural analysis and structured teaching.
- Speech and language therapy, occupational therapy, social skills training.
- Special education in structured classes.
- Parent training and family support.
- Medicines for associated problems only:
| Problem | Drug |
|---|---|
| Aggression, irritability, self-injury | Risperidone (antipsychotics) |
| Anxiety, repetitive or compulsive behaviour, depression | SSRIs; clomipramine (Akbar) |
| Hyperactivity, inattention | Stimulants (response less reliable), alpha-2 agonists |
| Sleep problems | Melatonin first-line |
| Seizures | Antiepileptic drugs |
Prognosis
Better outcome with:
- Early diagnosis and intensive therapy.
- Higher IQ (especially non-verbal).
- Useful speech by about 5-6 years.
Most affected adults still need some support; only a minority live fully independently.
Expect: ADHD core triad, onset before 12 years, two settings, at least 6 months; boys more often; differential such as hearing loss, absence seizures, sleep apnoea and lead; stimulants as first-line with appetite and sleep side effects; clonidine or atomoxetine when tics coexist; tic definition and Tourette syndrome (multiple motor plus vocal tics over a year), association with ADHD and OCD, treatment with education, clonidine or pimozide; autism triad, onset before 3 years, red flags, hearing test, fragile X, Rett syndrome in girls with hand-wringing, early behavioural therapy, risperidone for aggression, and good prognostic factors.
Quick revision
- ADHD: inattention, hyperactivity, impulsivity; before 12; two settings; 6 months.
- Boys 2-6 times more; heritability about 0.8; dopamine and noradrenaline.
- Stimulants first-line; side effects poor appetite, poor sleep; check heart.
- Clonidine or atomoxetine if tics or misuse risk.
- Tics: sudden, non-rhythmic; transient tics common; start 4-6, peak 10-12.
- Tourette: multiple motor plus one vocal tic, over 1 year; ADHD and OCD common.
- Autism: social, communication, repetitive behaviour; onset before 3.
- Test hearing and fragile X; seizures in about a quarter.
- Early intensive behavioural therapy; drugs only for associated symptoms.
- Better outlook: higher IQ, useful speech by 5-6 years.
Written by The House Job from standard references (Basis of Paediatrics by Pervez Akbar; Nelson Essentials of Paediatrics).
FAQ
Is ADHD just bad parenting?
No. ADHD is a highly inherited brain-based disorder. Stress and inconsistent parenting can make symptoms worse, but they do not cause the condition, and behaviour support for parents is part of treatment.
Do stimulants make children with ADHD addicted to drugs?
No. When used properly, stimulants lower the risk of later drug misuse. Their common side effects are poor appetite and trouble sleeping.
Do children grow out of tics?
Most do. Tics are worst around 10-12 years and usually improve a lot or stop by the late teens. Most children need only education and reassurance.
Can autism be cured with medicine?
No medicine treats the core features of autism. Early intensive behavioural, speech and educational therapy gives the best results, and drugs are used only for problems such as aggression, poor sleep or seizures.