Bipolar Disorder
Summary
Bipolar disorder is a chronic mood disorder characterised by episodes of mania or hypomania alternating with episodes of depression. It affects approximately 2% of the population and typically presents in late adolescence or early adulthood. Bipolar I disorder requires at least one manic episode; Bipolar II requires at least one hypomanic episode and one depressive episode. Treatment involves mood stabilisers (lithium, valproate), atypical antipsychotics, and psychological therapy. Lifelong treatment is usually required to prevent relapse. Suicide risk is high, particularly during depressive episodes.
Key Facts
- Definition: Recurrent episodes of mania/hypomania and depression
- Prevalence: ~2% lifetime
- Types: Bipolar I (mania required), Bipolar II (hypomania + depression)
- Mania Duration: ≥7 days (or any duration if hospitalised)
- Hypomania Duration: ≥4 days
- First-Line Treatment: Lithium (gold standard), valproate, atypical antipsychotics
- Suicide Risk: 15-20x general population
Clinical Pearls
"DIGFAST for Mania": Distractibility, Insomnia (decreased need for sleep), Grandiosity, Flight of ideas, Activity increase, Speech pressure, Thoughtlessness (risk-taking).
"Antidepressant Monotherapy is Dangerous": Never use antidepressants alone in bipolar depression — risk of manic switch. Always combine with mood stabiliser.
"Lithium Level Matters": Narrow therapeutic range (0.6-1.0 mmol/L). Monitor levels religiously — toxicity is serious.
Why This Matters Clinically
Bipolar disorder is frequently misdiagnosed as unipolar depression. Delayed diagnosis (average 10 years) leads to inappropriate treatment, manic switches, and worse outcomes. Correct diagnosis and mood stabiliser treatment dramatically improve quality of life.
Prevalence
| Measure | Value |
|---|---|
| Lifetime Prevalence | ~2% (Bipolar I + II) |
| Bipolar I | 1% |
| Bipolar II | 1% |
| Age of Onset | Late teens to mid-20s |
Demographics
| Factor | Details |
|---|---|
| Sex | Equal prevalence |
| Age of Onset | Peak 15-25 years |
| Delay to Diagnosis | Average 10 years |
Risk Factors
| Factor | Details |
|---|---|
| Genetics | 70% heritability; 10x risk if first-degree relative |
| Childhood Trauma | Associated with earlier onset |
| Substance Use | Common comorbidity; worsens course |
Neurobiological Factors
- Dysregulation of prefrontal cortex–amygdala circuits
- Dopamine overactivity (mania)
- Serotonin/noradrenaline dysregulation (depression)
- Mitochondrial dysfunction
- Circadian rhythm abnormalities
Kindling Model
- Repeated episodes lower threshold for future episodes
- Supports early, aggressive treatment
Manic Episode Features (DIGFAST)
| Symptom | Description |
|---|---|
| Distractibility | Unable to focus |
| Insomnia | Decreased need for sleep (feels rested on 2-3 hours) |
| Grandiosity | Inflated self-esteem, unrealistic beliefs |
| Flight of Ideas | Racing thoughts |
| Activity | Increased goal-directed activity |
| Speech | Pressured, rapid, difficult to interrupt |
| Thoughtlessness | Risky behaviour (spending, sexual, business) |
Depressive Episode
Red Flags
[!CAUTION] Red Flags:
- Suicidal ideation (especially depressive phase)
- Psychotic features (delusions, hallucinations)
- Severe mania with lack of insight
- Rapid cycling (≥4 episodes/year)
- Mixed features (mania + depression simultaneously)
Mental State Examination (Mania)
| Domain | Findings |
|---|---|
| Appearance | Bright clothing, dishevelled, over-groomed |
| Behaviour | Overactive, disinhibited, intrusive |
| Speech | Pressured, loud, difficult to interrupt |
| Mood | Elevated, euphoric, labile, irritable |
| Thought Form | Flight of ideas, tangential |
| Thought Content | Grandiose delusions |
| Perception | Hallucinations (if psychotic) |
| Cognition | Often intact but distractible |
| Insight | Usually impaired |
| Test | Purpose |
|---|---|
| Mood Diary | Track episodes |
| MDQ | Mood Disorder Questionnaire (screening) |
| TFTs | Exclude hyperthyroidism |
| U&E, eGFR | Baseline for lithium |
| LFTs | Baseline for valproate |
| Urine Drug Screen | Exclude substance-induced |
| Pregnancy Test | Before valproate |
Acute Mania
- Antipsychotic (olanzapine, risperidone, quetiapine)
- Lithium or valproate
- Benzodiazepine if agitated
- Stop antidepressants
Acute Bipolar Depression
- Quetiapine, lurasidone, or lamotrigine
- Avoid antidepressant monotherapy
- ECT for severe/treatment-resistant
Maintenance
- Lithium (gold standard)
- Valproate, quetiapine, olanzapine
- Lamotrigine (depression predominant)
- Lifelong treatment usually required
| Complication | Notes |
|---|---|
| Suicide | 15-20x increased risk |
| Substance Misuse | 50% comorbidity |
| Relationship/Work Problems | During manic episodes |
| Lithium Toxicity | Narrow therapeutic index |
| Metabolic Syndrome | Antipsychotic-induced |
| Hypothyroidism | Lithium-induced |
Course
| Pattern | Notes |
|---|---|
| Recurrence | 90% have recurrent episodes |
| Cycling | Average 0.4 episodes/year |
| Rapid Cycling | ≥4 episodes/year; worse prognosis |
Prognostic Factors
| Good | Poor |
|---|---|
| Later onset | Early onset |
| Good treatment adherence | Poor adherence |
| Good social support | Rapid cycling |
| Predominant mania | Mixed features |
Key Guidelines
- NICE CG185: Bipolar disorder (2014, updated 2023)
Landmark Trials
BALANCE (2010) — Lithium + Valproate comparison
- Key finding: Lithium more effective than valproate for relapse prevention
- Clinical Impact: Lithium remains gold standard
What is Bipolar Disorder?
Bipolar disorder is a condition that causes extreme mood swings. You may have periods of very high energy and excitement (mania) and periods of very low mood (depression).
What are the symptoms?
During mania:
- Feeling "on top of the world"
- Needing much less sleep
- Talking very fast
- Making impulsive decisions (spending, risky behaviour)
During depression:
- Feeling sad, hopeless
- No energy or motivation
- Difficulty sleeping or sleeping too much
How is it treated?
- Mood stabilisers: Lithium is the most effective for preventing episodes
- Antipsychotics: Help with mania
- Talking therapies: Help you recognise warning signs and manage stress
- Lifestyle: Regular sleep, avoiding alcohol and drugs
What to expect
- With treatment, most people can live well
- You'll likely need medication long-term
- Regular blood tests are needed for lithium
Primary Guidelines
- National Institute for Health and Care Excellence. Bipolar disorder: assessment and management (CG185). 2014. nice.org.uk/guidance/cg185
Key Trials
- Geddes JR, Goodwin GM, Rendell J, et al. Lithium plus valproate combination therapy versus monotherapy for relapse prevention in bipolar I disorder (BALANCE). Lancet. 2010;375(9712):385-395. PMID: 20092882
Further Resources
- Bipolar UK: bipolaruk.org
- Mind: mind.org.uk
Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. If you are experiencing a mental health crisis, please seek help immediately.