Mental Health

Bipolar disorder

A recurrent mood disorder defined by episodes of mania or hypomania, often with depression, requiring urgent risk assessment, polarity-specific treatment and long-term relapse prevention.

In a nutshell

Bipolar disorder is defined by episodes of mania or hypomania, often alternating with depression. Suspected mania or severe depression needs urgent specialist assessment and risk management. Treat acute mania with an antipsychotic pathway, bipolar depression with NICE-specified options rather than antidepressant monotherapy, and offer lithium first line for long-term relapse prevention with structured monitoring. Valproate requires strict current MHRA safeguards.

Classic presentation

A distinct period of elevated or irritable mood with increased energy, reduced need for sleep, pressured speech, racing thoughts, grandiosity and risky behaviour, with or without later depressive episodes.

Key points

Ask about past mania or hypomania in every patient presenting with depression; obtain collateral history when possible.
Mania causes marked impairment, psychosis or hospital-level severity; hypomania is less severe and does not include psychosis or marked impairment.
Suspected mania, severe depression, mixed symptoms, psychosis or danger to self or others requires urgent specialist mental-health assessment.
For acute mania, use an antipsychotic pathway and consider stopping antidepressant monotherapy; do not use lamotrigine for mania.
For moderate or severe bipolar depression, NICE options include fluoxetine with olanzapine or quetiapine, with olanzapine or lamotrigine as alternatives.
Lithium is first-line long-term treatment and needs level, renal, thyroid, calcium and clinical-toxicity monitoring.
Valproate must not be initiated under 55 without the current two-specialist exception, and women, girls and men need current reproductive-risk counselling.
Include sleep, substances, physical health, family or carer support, crisis planning, suicide prevention and cardiometabolic monitoring.

First-line investigation

Longitudinal and collateral history of elevated episodes, risk assessment, medication and substance review, physical examination, FBC, renal function and electrolytes including calcium, thyroid function, glucose or metabolic baseline, and pregnancy testing where relevant.

Management

Recognise polarity and urgent risk

Take longitudinal and collateral history, assess suicide, self-harm, psychosis, danger, neglect and capacity, and refer suspected mania or severe depression urgently.^1,2

Treat acute mania safely

Offer a NICE antipsychotic pathway for mania or hypomania, consider stopping antidepressant monotherapy and escalate to lithium or specialist valproate only in the recommended sequence.^1,4,3

Treat bipolar depression by the NICE pathway

Use fluoxetine with olanzapine or quetiapine, with olanzapine or lamotrigine as alternatives, alongside psychological therapy and close monitoring for switching or suicidality.^1,3

Establish long-term mood stabilisation

Offer lithium first line with shared care, early and ongoing levels, renal, thyroid, calcium and toxicity monitoring; use alternatives only after specialist review.^1,3

Apply valproate and comorbidity safeguards

Do not initiate valproate under 55 without the current two-specialist exception; follow reproductive-risk safeguards and treat substance use, pregnancy, physical and mental comorbidity in parallel.^1,4,2

Use a written relapse-prevention plan

Record early warning signs, preferred responses, crisis contacts, sleep and substance triggers, family or carer involvement, monitoring and gradual medication changes.^1,5,2

Exam traps

Depression alone does not establish bipolar disorder, and a family history alone is not diagnostic.
Reduced need for sleep is different from insomnia with fatigue; the person may feel rested despite sleeping less.
Antidepressant monotherapy is not the NICE pathway for bipolar depression and may destabilise mood.
Lamotrigine is used in bipolar depression and prevention, not for acute mania.
Lithium toxicity can occur at a therapeutic level; tremor, ataxia, paraesthesia and cognitive change require urgent review.
Valproate initiation under 55 is a current regulatory safety decision, not a routine alternative to lithium.
Mixed manic and depressive symptoms can combine high energy with suicidal thinking and are especially dangerous.

Illustrations

Mood-circuit instability schematicDiagram showing bipolar disorder as recurrent instability across mood, reward and arousal systems, with depressive and manic poles and stabilising treatment across both.PassFinals · original

Mania versus hypomaniaSide-by-side comparison of the shared symptoms of mania and hypomania and the features that make mania more severe, impairing or psychotic.PassFinals · original

Longitudinal mood chartExample chart plotting manic, depressive, mixed and euthymic periods alongside sleep, medication, triggers and relapse-prevention actions.PassFinals · original

Key sources

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.