9.7.4 Affective disorders in children and adolescents

Epidemiology of depression

• About one in five young people in community samples has had a major depressive episode by age 18.

• About 5% of adolescents are depressed at any one time, against about 40% of adolescents in hospital.

• The sex ratio is equal before puberty; a female excess of about 2:1 is in place by mid-adolescence and lasts through adult life.

• Bipolar disorder is very rare before puberty and becomes more apparent during adolescence.

• Genetic, cognitive, family, circadian and social factors interact in causation, and bipolar disorder has a higher estimated heritability than depression.

Comorbidity of depression

• Anxiety disorders are the commonest comorbid group in depressed children and adolescents.

• The link is asymmetric: depression is found less often in anxious youth than anxiety is found in depressed youth.

Presentation of depression across development

Depression shows itself through the channel that fits the child's developmental stage.

• Before puberty, behavioural and somatic symptoms dominate.

• In older children and adolescents, cognitive, verbalised symptoms such as low self-esteem and hopelessness about the future become more prominent.

• Depression in young people may present as irritability rather than sadness.

• Falling attendance, attainment, peer contact or self-care may be the first visible change, so judge anhedonia against the child's own interests.

• For each self-harm episode, ask about intent, planning, access to means and rescue, and use safety planning rather than predictive risk categories.

Stepped care for depression

• Medication is given only alongside psychological therapy; if the young person declines therapy, monitor particularly closely.

• Follow-up lasts 12 months after a first episode and 24 months after recurrent depression.

• A 17-year-old recovering from a first episode may stay with child and adolescent mental health services (CAMHS) beyond 18 until discharge.

Antidepressants

• Fluoxetine is the first-choice antidepressant under 18 in National Institute for Health and Care Excellence (NICE) guidance; it alone has consistent placebo-controlled paediatric evidence and a UK licence.

• It is started after four to six sessions of psychological therapy without response and a multidisciplinary review, and therapy continues alongside it.

• At 12 to 18, combined fluoxetine and therapy from the start is also an option for moderate to severe depression.

• NICE allows fluoxetine to be considered cautiously from age 5, after psychological therapy has failed; the UK licence starts at age 8.

• The paediatric starting dose is 10 mg daily, raised to 20 mg after one to two weeks if needed; 20 mg is the adult starting dose.

• Sertraline or citalopram are second line, off-label.

• Paroxetine and venlafaxine must not be used, because paediatric trials showed more suicidal ideation, self-harm and hostility; tricyclics and St John's wort are also avoided.

• In the TADS trial, 12-week response was about 61% on fluoxetine against 35% on placebo, and fluoxetine with CBT did better still.

• People continue effective treatment for at least six months after sustained remission.

Clinicians see the young person often in the first four weeks, commonly weekly, and watch for activation (restlessness, agitation, insomnia), emergent suicidal thoughts, self-harm or hostility, and a switch into mania.

Recognising bipolar disorder

Mania is a distinct change from baseline in both mood and energy, with associated symptoms and impairment.

• Mania in young people often departs from the adult euphoric picture: mixed states, irritability and rapid mood lability are common.

• An abrupt change from a settled baseline with reduced need for sleep, pressured speech, grandiosity and reckless behaviour, in irritable mood, is mania.

• A voice echoing the grandiose theme sits within the manic episode and does not signal a primary psychosis.

• Changes in energy, speech, sleep and grandiosity are reported in most young people with bipolar disorder; hypersexuality is the least frequent, present only in a minority.

• Hypomania is distinct spells of several days of raised energy, reduced need for sleep, pressured speech and irritability that others notice.

• One hypomanic episode plus a depressive episode is bipolar II, not recurrent depressive disorder.

• NICE requires specialist prospective monitoring before diagnosing bipolar disorder in a young person, and emphasises euphoria lasting at least seven days.

• Depression plus a family history of bipolar disorder warrants follow-up, not a bipolar diagnosis.

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Mania, ADHD and chronic irritability

• Reduced need for sleep, sleeping little yet feeling rested, occurs in mania but not in attention deficit hyperactivity disorder (ADHD), so it separates them when they coexist.

• ADHD is a longstanding developmental pattern, whereas mania is a distinct episode.

• Stimulant adverse effects and rebound can mimic mood symptoms.

• Chronic irritability predicts later depression and anxiety more strongly than bipolar disorder, in longitudinal work by Stringaris and Leibenluft.

• ICD-11 records persistent irritability between outbursts through oppositional defiant disorder with chronic irritability-anger, when the full requirements are met.

Comorbidity in paediatric bipolar disorder

ADHD is the commonest comorbid diagnosis.

Treatment of bipolar disorder

• Care involves a CAMHS or early intervention team with bipolar expertise.

• Antipsychotics are not extended beyond 12 weeks without reassessment.

• Valproate needs exceptional justification and current regulatory safeguards.

Electroconvulsive therapy

• NICE reserves electroconvulsive therapy for very severe, life-threatening or intractable depression in young people, in a specialist setting, and does not recommend it at 5 to 11.

• Under 18, section 58A of the Mental Health Act 1983 requires an independent appointed doctor to certify consent and appropriateness, even for consenting informal patients.