Bipolar disorder
Exam Tips
- Mania requires at least 7 days (or any duration if hospitalisation/psychosis), hypomania at least 4 days with no psychosis or marked functional impairment.
- In OSCE depression stations, actively screen for past hypomanic/manic episodes (overactivity, reduced need for sleep, disinhibition) to avoid missing bipolar disorder.
- Do not diagnose bipolar disorder in primary care using questionnaires alone; diagnosis requires specialist assessment with collateral history.
- For bipolar depression, avoid antidepressant monotherapy; use bipolar-specific regimens and monitor for switch into mania.
- Lithium monitoring is a frequent UK exam topic: 12-hour levels plus renal, thyroid, calcium, and toxicity counselling.
- Valproate teratogenicity and UK Pregnancy Prevention Programme requirements are high-yield safety points.
Definition
Bipolar disorder is a chronic episodic mood disorder characterised by pathological shifts between elevated mood states (hypomania or mania) and depression, with periods of partial or full remission between episodes. Mania involves at least 7 days of abnormally elevated, expansive, or irritable mood with increased activity and marked functional impairment and/or psychosis, while hypomania lasts at least 4 days without psychosis or severe functional collapse. Diagnosis and subtype classification (bipolar I vs bipolar II) require specialist mental health assessment in UK practice.
Pathophysiology
Bipolar disorder is best understood as a neurobiological illness with strong genetic loading (around 70% heritability) plus environmental triggers. Current models describe dysregulation across fronto-limbic networks (prefrontal cortex, amygdala, striatum), altered monoaminergic and glutamatergic signalling, circadian rhythm instability, HPA-axis stress dysregulation, and inflammatory/mitochondrial abnormalities that may contribute to episode recurrence and cognitive decline over time. Kindling/sensitisation concepts explain why repeated episodes can become more frequent with shorter euthymic intervals. Image reference: see standard psychiatry textbook diagrams of fronto-limbic circuitry and circadian clock dysregulation in bipolar disorder chapters.
Risk Factors
- First-degree family history of bipolar disorder (substantially increased lifetime risk)
- Adverse childhood experiences (trauma, abuse, neglect, early parental loss)
- Cannabis or cocaine use
- Postpartum period (postpartum psychosis can be first presentation)
- Possible in utero infectious exposures (for example toxoplasma, CMV, HSV associations)
- Prior depressive episodes with early onset and episodic pattern
Clinical Features
Symptoms
- Episodic elevated or irritable mood with increased energy/activity
- Reduced need for sleep (feels rested after very little sleep)
- Racing thoughts, distractibility, and pressure of speech
- Disinhibition, increased libido, impulsive spending/risk-taking
- Depressive episodes: persistent low mood or anhedonia, low energy, hopelessness, suicidal ideation
- Mixed features: coexisting depressive and manic symptoms within same period
Signs
- Psychomotor agitation, overfamiliarity, and intrusive behaviour during mania/hypomania
- Rapid, loud, difficult-to-interrupt speech; flight of ideas
- Grandiose delusions or hallucinations in severe mania
- Neglect of self-care, dehydration, exhaustion in prolonged episodes
- Objective functional deterioration (work, finances, relationships, legal/social harm)
- Possible psychomotor retardation or catatonic features in severe depressive phases
Investigations
Management
Lifestyle Modifications
- Psychoeducation for patient and family (early warning signs, relapse prevention plan, adherence)
- Regular sleep-wake routine and circadian stabilisation; avoid sleep deprivation
- Avoid alcohol and recreational drugs (especially cannabis/cocaine)
- Structured daily routine, stress management, and support for employment/finances/relationships
- Crisis planning including who to contact if mania, psychosis, or suicidality escalates
Pharmacological Treatment
Acute mania/hypomania (first-line antipsychotic options)
- Olanzapine 10 mg once daily initially; usual range 5-20 mg/day
- Quetiapine (immediate release) titrated from 100 mg day 1 to 400 mg day 4; usual 400-800 mg/day in divided doses
- Risperidone 2 mg once daily initially; usual range 1-6 mg/day
- Haloperidol 2-10 mg/day in divided doses (dose individualised to response and adverse effects)
Choose based on prior response, side-effect profile, and comorbidity. If inadequate response, switch antipsychotic; if still inadequate, consider adding lithium. Monitor for EPS, metabolic effects, sedation, prolactin effects, and QT prolongation.
Mood stabiliser (acute mania adjunct and long-term relapse prevention)
- Lithium carbonate modified-release usually 400 mg at night initially (200 mg in older/frail adults), then titrate to 12-hour plasma level target (commonly 0.6-0.8 mmol/L maintenance; often 0.8-1.0 mmol/L in acute treatment if tolerated)
Key safety: narrow therapeutic index; toxicity risk rises with dehydration, AKI, NSAIDs, ACE inhibitors, and thiazide diuretics. Monitor lithium level, renal function, thyroid function, calcium, and weight regularly; counsel on fluid/salt consistency and toxicity symptoms (tremor, diarrhoea, ataxia, confusion).
Bipolar depression
- Fluoxetine 20 mg once daily combined with olanzapine (for example olanzapine 5-20 mg/day)
- Quetiapine for bipolar depression: 50 mg day 1, 100 mg day 2, 200 mg day 3, 300 mg day 4; usual target 300 mg at night
- Lamotrigine titration: 25 mg once daily for 2 weeks, then 50 mg once daily for 2 weeks, then increase toward usual 200 mg/day maintenance (adjust with interacting drugs)
Avoid antidepressant monotherapy in bipolar depression due to switching risk into mania/hypomania. Lamotrigine requires slow titration to reduce serious rash risk (including SJS/TEN); stop urgently if rash with systemic features develops.
Valproate-containing regimens (selected adults only)
- Sodium valproate (or semisodium valproate) often started at 750 mg/day in divided doses, or about 20 mg/kg/day, then adjusted to response/tolerability
Major UK warning: contraindicated in pregnancy unless strict Pregnancy Prevention Programme requirements are met; avoid in women/girls of childbearing potential unless no effective alternative. Monitor LFTs, FBC/platelets, and pancreatitis/hepatotoxicity symptoms.
Surgical / Interventional
- Electroconvulsive therapy (ECT) can be considered for severe or treatment-resistant bipolar depression/mania, especially with psychosis, catatonia, or urgent high-risk clinical states
Complications
- High lifetime risk of suicidal ideation, suicide attempt, and completed suicide
- Deliberate self-harm and accidental injury (including road traffic accidents during disinhibited states)
- Financial, occupational, legal, and relationship breakdown due to impulsive/risky behaviour
- Sexual risk-taking, STI exposure, and unplanned pregnancy
- Substance and alcohol misuse, gambling-related harms, exploitation vulnerability
- Physical multimorbidity (cardiovascular disease, obesity, type 2 diabetes, dyslipidaemia, CKD, respiratory disease)
- Functional and cognitive decline with recurrent episodes
Prognosis
Bipolar disorder is lifelong with a relapsing-remitting course and substantial inter-individual variability. Relapse is common (about 50% within 1 year after an episode and around 75% within 4 years), particularly with poor adherence, incomplete recovery, substance misuse, and sleep disruption. Long-term outcomes improve with early specialist care, sustained pharmacological treatment, psychoeducation, and close monitoring for suicide risk and cardiometabolic disease.
Sources & References
🏥BMJ Best Practice(4)
💊BNF Drug References(17)
- Agomelatine[cautions]
- Amitriptyline hydrochloride[cautions]
- Bupropion hydrochloride[contraindications]
- Carbamazepine[management.pharmacological]
- Clomipramine hydrochloride[cautions]
- Dapoxetine[contraindications]
- Dosulepin hydrochloride[cautions]
- Doxepin[cautions]
- Imipramine hydrochloride[cautions]
- Lamotrigine[management.pharmacological]
- Lisdexamfetamine mesilate[cautions]
- Lofepramine[cautions]
- Mianserin hydrochloride[cautions]
- Nortriptyline[cautions]
- Reboxetine[cautions]
- Trazodone hydrochloride[cautions]
- Trimipramine[cautions]
✅NICE Guidelines(1)
- Bipolar disorder[overview]
📖Textbook References(1)
- Guyton and Hall Textbook of Medical Physiology (John E. Hall, Michael E. Hall) (Z-Library).pdf(pp. 751)[context]