9.7.11 Other childhood disorders

Assessing against a developmental norm

• Developmental age is the yardstick. Behaviour is judged by its persistence, its context and its effect on daily life, and a single missed milestone or odd behaviour does not settle a diagnosis.

• Presentations are often indirect, for example school avoidance from selective mutism, or wetting again after a child had been dry.

Epidemiology of childhood psychiatric disorder

• The Isle of Wight studies (Rutter) surveyed 10 and 11 year olds and found a psychiatric disorder in about 7%.

• Conduct disorders and emotional disorders were the two commonest groups, at roughly equal frequency.

Enuresis

Definition

• Enuresis is not diagnosed before a developmental age of 5 years in ICD-11 (International Classification of Diseases, 11th revision), because almost all children have daytime bladder control by five.

• ICD-11 requires repeated, persistent wetting, typically several times a week over several months, after excluding medical and substance-related causes.

• Secondary enuresis is wetting after at least six dry months, and a psychosocial stressor may precipitate it.

• Enuresis can also occur as part of another mental or neurodevelopmental disorder.

Epidemiology and causes

• Prevalence falls by a fixed share each year because the condition is largely self-limiting: about 15% of affected children become dry each year without treatment.

• Nocturnal enuresis is commoner in boys.

• It is strongly familial. About three-quarters of affected children have an affected first-degree relative, and a parental history of bedwetting is the strongest single predictor of non-organic enuresis.

• It clusters with social disadvantage: large families, overcrowding and low socioeconomic status.

• Constipation, urinary infection, diabetes and sleep-disordered breathing can contribute. Suspected type 1 diabetes needs same-day referral.

Management

• Under 5 years, a well child with normal development and no physical cause gets reassurance and simple advice, not active treatment.

• First step in primary nocturnal enuresis: adequate drinks spread through the day, no caffeine, and toileting that includes a visit just before sleep.

• Rewards go to agreed behaviour, such as drinking well or using the toilet before bed, not to dry nights, and earned rewards are never removed.

• Routine lifting or waking the child does not produce lasting dryness.

Enuresis alarm

• The alarm is first-line active treatment once advice and rewards have failed, when wetting is frequent and a motivated family can respond at night.

• It is the best-evidenced treatment for primary nocturnal enuresis without daytime symptoms. It conditions the child to wake to a full bladder and gives durable dryness with the lowest relapse after stopping.

• Response is checked at four weeks, and the alarm continues until the child has had two weeks of dry nights.

Tap to enlarge

Desmopressin

• Desmopressin reduces overnight urine production from the first nights, so it is used when rapid, short-term dryness is needed for a fixed event.

• After a failed alarm trial in primary enuresis without daytime symptoms or constipation, it is given as a single 200 microgram tablet at bedtime.

• It is offered from age 7 and considered from 5 to 7. Response is reviewed at four weeks, and a responsive course usually runs for three months.

• Fluids are limited from one hour before until eight hours after the dose because of the risk of hyponatraemia, and the drug is stopped during illness that upsets fluid balance.

The alarm and desmopressin differ in what happens afterwards: dryness after the alarm tends to last, while relapse after stopping desmopressin is common.

Imipramine

• Imipramine is the antidepressant historically used, and still licensed in the UK, for nocturnal enuresis. It is considered only after every other treatment has failed, under specialist assessment.

• It is given for three months, then withdrawn gradually. It is dangerous in overdose and slows cardiac conduction.

Encopresis

• Encopresis is the repeated passage of faeces in inappropriate places from a chronological or developmental age of four years, by which about 95% of children have bowel control.

• About 90% is functional (idiopathic) and under 10% is organic.

• It affects roughly 1 to 3% of 4 year olds and 1 to 2% at about age 10 (around 1.6% in survey data).

Exclude organic causes first

• Hirschsprung disease (aganglionic megacolon) is the main organic cause.

• Tethered spinal cord is another physical cause to exclude.

• Hypothyroidism and coeliac disease also cause constipation that resists treatment.

• Neonatal onset, delayed meconium, abnormal stools or neurological signs point to an organic cause.

• Abdominal radiographs are not used routinely for idiopathic constipation.

Overflow soiling and treatment

• Overflow soiling is the usual mechanism: painful stools lead to withholding, impaction and rectal distension, and liquid stool leaks around the retained faeces. Apparent diarrhoea can therefore mean constipation.

• Disimpaction uses an escalating macrogol regimen, with a stimulant laxative added if it fails after two weeks. Pain and soiling may worsen at first.

• Maintenance often starts at about half the disimpaction dose and is reduced gradually over months, never stopped abruptly.

• Laxatives are combined with scheduled toileting, a bowel diary, fluids and diet. Diet alone is not adequate first-line treatment.

• Star charts and stickers are behaviour modification, an application of operant conditioning.

• Children are never blamed or punished for involuntary wetting or soiling.

Sleep disorders

ICD-11 gives sleep-wake disorders their own chapter, so the specific sleep disorder is identified rather than every sleep complaint being treated as psychiatric.

Parasomnias

Parasomnias are classed by sleep stage. Sleep terrors and sleepwalking are non-REM disorders of arousal, while nightmare disorder, REM sleep behaviour disorder and sleep paralysis are REM (rapid eye movement) parasomnias.

Tap to enlarge

• Sleep terrors are also called pavor nocturnus, and the child has amnesia for the episode.

• N3 sleep shows delta waves on the electroencephalogram (EEG), while REM sleep shows sawtooth waves.

• Sleepwalking often runs in families.

Tap to enlarge

Other sleep disorders

• Children with sleep apnoea may look overactive and inattentive rather than sleepy.

• Kleine-Levin syndrome is told from narcolepsy by its course: discrete episodes with normal functioning between, against the chronic daily sleepiness of narcolepsy.

Melatonin and sleep hygiene

• Melatonin for insomnia in children with neurodevelopmental conditions most reliably shortens sleep onset latency and lengthens total sleep time. The effect is modest and persists with continued use.

• These gains show on objective as well as reported measures, and melatonin does not disrupt sleep architecture as benzodiazepines do.

• Prolonged-release melatonin products are licensed, when sleep hygiene is not enough, for insomnia with autism or specified neurogenetic disorders at 2 to 18 years, and with attention deficit hyperactivity disorder (ADHD) at 6 to 17.

• Sleep hygiene for initial insomnia in an adolescent includes a warm bath one to two hours before bed.

Learning, motor and communication disorders

Specific learning disorders

• Dyslexia (ICD-11 developmental learning disorder with impairment in reading) is an isolated literacy deficit in a child of normal intelligence and normal spoken language, and affects about 4% of school-age children.

• Dyslexia is a phonological processing deficit: word reading is slow and inaccurate, made-up words cannot be decoded and rhyme awareness is poor, while listening comprehension is intact.

• The male to female ratio in dyslexia is about 2:1 at a cut-off two standard deviations below the mean and about 4:1 at three, because boys' reading scores are more variable.

• Disorder of written expression often coexists with dyslexia.

• Dyscalculia shows misaligned columns, place-value errors and poor copying of shapes, and is linked to parietal dysfunction, classically right-sided.

• Dyscalculia is the exception among specific learning disorders: reading, writing, language and speech disorders all have a male excess.

Tap to enlarge

Developmental coordination disorder

• Developmental coordination disorder is motor skill below age and opportunity that interferes with daily life, affecting around 6% of school-age children.

• It shows in handwriting, dressing, using cutlery and avoiding physical education, and occupational therapy and physiotherapy teach the tasks.

Speech and language

• Developmental language disorder, mainly expressive subtype, is spoken output well below age level with intact comprehension, hearing, articulation, non-verbal ability and social communication. Impaired comprehension makes it the mixed receptive and expressive subtype.

• Receptive problems can look like inattention or defiance, so hearing and the whole developmental profile are assessed.

• Stuttering (childhood-onset fluency disorder) is sound repetitions and silent blocks at the start of words, with secondary behaviours such as blinking and tapping. Fluency returns during singing and worsens with stress.

• Cluttering differs from stuttering: it is rapid, irregular speech with collapsed syllables.

• Stuttering carries a raised incidence of social anxiety, with school refusal and wider anxiety symptoms.

• Auditory processing disorder is difficulty making sense of heard speech, worst in background noise, despite normal peripheral hearing and normal functioning in quiet.

School refusal and selective mutism

The school refusal column follows Berg's criteria.

• Selective mutism is consistent inability to speak in some settings, usually school, while the child speaks in others. It lasts at least a month, not counting the first month of school.

• It is not diagnosed when unfamiliarity with the language, or an ordinary silent period while learning another language, explains the silence. Autism, language disorder and hearing loss are the other differentials.

• It is a rare, anxiety-based disorder (older UK estimates 3 to 8 per 10,000) with early onset and a sex ratio that does not favour boys. Residual difficulty after recovery is frequent.

• Most affected children also meet criteria for social anxiety disorder.

• Treatment is graded, supported speaking practice. It starts where the child speaks comfortably with a trusted person, adds people and settings in small steps, and shapes sounds into words with positive reinforcement.

• School and home share one plan and avoid public pressure to speak. Fluoxetine has been studied as an adjunct for severe anxiety, under specialist care.

Oppositional defiant disorder

• Oppositional defiant disorder is persistent irritability, argumentativeness, defiance or vindictiveness beyond developmental expectation, without the serious rights violations of conduct disorder. A normal school report does not exclude it.

• ICD-11 specifies whether oppositional defiant disorder occurs with chronic irritability-anger; this is persistent between outbursts, not an episodic manic state.

• Irritability predicts later anxiety and depression, while defiance predicts conduct problems.

• The National Institute for Health and Care Excellence (NICE) recommends social learning parent programmes at 3 to 11 years and problem-solving groups at 9 to 14. Medication is not used for the disorder itself.

Post-traumatic stress disorder in children

• Childhood post-traumatic stress disorder (PTSD) is shaped by development: post-traumatic play, regression, new separation fear and nightmares without recognisable content appear within the ICD-11 pattern of re-experiencing, avoidance and persistent current threat.

• The child must be asked directly, apart from the carer where possible, about the trauma and symptoms, because parents under-report re-experiencing symptoms.

• Individual trauma-focused cognitive behavioural therapy is first-line under NICE NG116 for those aged 7 to 17 presenting more than a month after the trauma.

• NG116 (2018) recommends no drug for preventing or treating PTSD under 18, and rejects debriefing at every age.

• Indiscriminate friendliness towards strangers belongs to disinhibited social engagement disorder, which follows grossly insufficient care such as neglect, not to PTSD.

Self-harm and suicide in young people

• Suicidal ideation is uncommon before about 10, rises gradually from 10 to 12, then rises steeply through adolescence to about 17.

• Completed suicide is commoner in boys, while self-harm and non-fatal attempts are commoner in girls.

• Hanging or strangulation is the leading method of completed suicide, whereas self-poisoning and cutting dominate non-fatal self-harm.

• Self-injurious thoughts and behaviours are the commonest reason for psychiatric emergency presentation in children and adolescents.

Myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS)

• The core symptoms under NICE (2021) are debilitating fatigue unrelieved by rest and worsened by activity, post-exertional malaise, unrefreshing or disturbed sleep, and cognitive difficulties. Other symptoms are only associated.

• Brain fog means problems with word-finding, short-term memory and concentration.

• The sleep complaint is non-restorative sleep, which may take the form of hypersomnia, not a discrete primary sleep disorder such as narcolepsy or a parasomnia.

Rett syndrome

• Rett syndrome is regression in a girl after apparently normal early development, with loss of speech and purposeful hand use, midline hand stereotypies, gait disturbance and slowing head growth.

• Seizures and disordered breathing while awake, such as hyperventilation and breath-holding, are common.

• It is a single-gene disorder (MECP2 on Xq28), so monozygotic twins are concordant.

Tap to enlarge

Other conditions

• Pica is persistent eating of non-nutritive, non-food substances for more than a month, beyond the stage where mouthing is normal. It typically begins in the second and third years and affects boys and girls equally.

• Recurrent abdominal pain is commonly functional and linked to anxiety: vague, central, poorly localised and clustered around stressors, unlike organic pain.

• Recurrent abdominal pain is the commonest bodily complaint in children with ICD-11 bodily distress disorder, ahead of headache, fatigue and musculoskeletal pain.

• Factitious disorder imposed on another is the current term for Munchausen syndrome by proxy: illness is falsified in another person to occupy a sick role, not for external gain.

• PANDAS (paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections) is supported by raised anti-streptolysin O or anti-DNase B titres, not by nonspecific inflammatory markers or other autoantibodies.

• Niemann-Pick disease types A and B are caused by acid sphingomyelinase deficiency, so sphingomyelin is stored in lysosomes.