Mood Disorders (F3)

Bipolar Disorder

Bipolar disorder is a chronic psychiatric illness characterized by recurrent episodes of mania or hypomania alternating with depressive episodes, resulting in significant disturbances in mood, energy, and functioning.

2. Epidemiology

3. Anatomy and Function (Neuroanatomy of Bipolar Disorder)

Understanding the neuroanatomy helps you make sense of the clinical features. Bipolar disorder involves dysfunction in cortico-limbic circuits that regulate mood, reward, and executive function.

4. Aetiology and Pathophysiology

Bipolar disorder is best understood through a multifactorial biopsychosocial model [1]. No single cause is sufficient — rather, it's the interaction of genetic vulnerability, environmental triggers, and neurobiological dysregulation.

4.1 Biological and Genetic Factors

4.2 Environmental Factors

5. Classification

5.4 Special Subtypes

6. Clinical Features

Now let's go through the clinical presentation systematically. I'll separate symptoms and signs, and connect everything back to the underlying pathophysiology.

6.1 Manic Episode

Differential Diagnosis of Bipolar Disorder

The differential diagnosis of bipolar disorder is one of the most clinically important exercises in psychiatry, because misdiagnosis is extremely common — correct diagnosis and treatment is delayed by 5–7 years on average [1][2]. Getting this wrong has real consequences: treat bipolar depression with antidepressant monotherapy and you risk triggering a manic switch and cycle acceleration; label someone with personality-driven irritability as "bipolar" and you expose them to unnecessary mood stabilizer side effects [1].

The approach to differential diagnosis depends on which pole the patient is presenting with — the differentials for a manic/hypomanic presentation are different from those for a depressive presentation. Let's be systematic.


1. Differential Diagnosis of the Manic / Hypomanic Presentation

The lecture slides give a clear list of differential diagnoses of a manic episode [1]:

  1. Depressive disorder with irritability and anxious distress
  2. Psychotic disorder or schizoaffective disorder
  3. Substance/medication-induced / medical conditions
  4. Attention deficit and hyperactivity disorder
  5. Personality disorder with prominent irritability

Let's go through each in detail.


2. Differential Diagnosis of the Depressive Presentation

The majority of bipolar disorder patients present with depression as their first episode [2]. This is the main source of the infamous diagnostic delay.

3. The Misdiagnosis and Overdiagnosis Problem

This is emphasised heavily in the lecture slides and deserves its own section [1]:

References

[1] Lecture slides: GC 163. I am a superman Bipolar disorder.pdf (p10, p11, p12, p13, p14, p15, p17, p22) [2] Senior notes: ryanho-psych.md (sections 7.3, 7.1.2, pp.357–402) [3] Lecture slides: GC 170. Schizophrenia and related psychoses.pdf (p22) [4] Senior notes: ryanho-psych.md (ADHD section, p.664)

Diagnostic Criteria for Bipolar Disorder

Getting the diagnostic criteria right is essential — as we've discussed, misdiagnosis is extremely common and correct diagnosis and treatment was delayed by 5–7 years on average [1]. The diagnosis is entirely clinical: there is no blood test, no imaging finding, no biomarker. It rests on a careful psychiatric history, mental state examination, collateral information, and rigorous application of diagnostic criteria [1].

Let's break this down systematically.


2. Diagnostic Criteria: Manic Episode (DSM-5)

The manic episode is the defining episode for Bipolar I disorder. Let me walk you through the DSM-5 criteria and explain the logic behind each one.

7. Investigations

Investigations in bipolar disorder serve three purposes:

  1. Exclude organic/substance-induced mania (differential diagnosis)
  2. Establish a baseline before starting mood stabilizers/antipsychotics (which have significant metabolic and organ-specific side effects)
  3. Screen for comorbidities and neglect

9. Assessment Framework: Putting It All Together

The senior notes provide a comprehensive assessment structure [2]:

References

[1] Lecture slides: GC 163. I am a superman Bipolar disorder.pdf (p3, p7, p8, p10, p11, p12, p13, p14, p15, p17, p22, p23, p24, p61) [2] Senior notes: ryanho-psych.md (sections 7.3, 7.1.2, pp.348–402)

Management of Bipolar Disorder

Managing bipolar disorder is fundamentally different from managing unipolar depression — and getting this wrong can be harmful. The overarching philosophy is: stabilise the mood in both directions (prevent highs AND lows), minimise harm from treatment, and sustain functional recovery over a lifetime. This is a chronic relapsing-remitting illness, so think of it like managing diabetes — acute treatment of crises, then long-term maintenance to prevent complications.


3. Phase 1: Treatment of Acute Mania / Hypomania

4. Phase 2: Treatment of Acute Bipolar Depression

This is where bipolar management diverges most sharply from unipolar depression. The lecture slides highlight this critical point [1]:

Because of the recognised risk of switching to manic or mixed episodes and the high risk of suicide, referral to a specialist should be considered [1]

4.2 Treatment Options

Treatment of bipolar depressive episode [1]:

  • Monotherapy: Lithium, Lamotrigine OR Quetiapine
  • Combination: Add Antidepressants (SSRI OR Venlafaxine) to monotherapy OR Combine two monotherapy agents
  • Re-evaluate diagnosis and consider ECT (for patients with high suicidal risk) [1]

5. Phase 3: Maintenance / Prophylactic Treatment

This is the most important phase for long-term outcomes. Recurrence rate reduces by 50% for maintenance vs. discontinuation [1].

5.3 Maintenance Treatment Options

6. Pharmacological Agents — Detailed Profiles

References

[1] Lecture slides: GC 163. I am a superman Bipolar disorder.pdf (p36, p40, p41, p42, p44, p45, p46, p47, p51, p59, p64, p65) [2] Senior notes: ryanho-psych.md (sections 3.1.3, 3.1.3.1, 3.2, 7.3 Management, pp.123–151, 403–408)

Complications of Bipolar Disorder

Bipolar disorder is not simply an illness of "mood swings." It is a systemic, chronic, progressive condition with devastating complications that span psychiatric, medical, social, cognitive, and treatment-related domains. Understanding these complications — and why they occur — is essential for holistic management.

The prognosis is sobering: only < 20% of patients achieve a 5-year period of clinical stability [2]. Life expectancy is ↓ by ~13 years (males) and ~9 years (females) [2]. The complications are what drive this excess morbidity and mortality.


2. Psychiatric Comorbidity

Psychiatric comorbidities are common and need to be treated alongside bipolar disorder [1]. They worsen the course, reduce treatment response, and increase functional impairment.

3. Medical Complications

Increased risk of medical comorbidity [1] is a major contributor to the ↓ life expectancy by 13 years (males) and 9 years (females) [2].

5. Functional and Social Complications

Bipolar disorder devastates social functioning, often disproportionately to the time spent acutely symptomatic.

References

[1] Lecture slides: GC 163. I am a superman Bipolar disorder.pdf (p14, p23, p24, p25, p26, p34, p41, p49, p64, p65) [2] Senior notes: ryanho-psych.md (sections 7.3 Course and Prognosis, Management, pp.397–408) [3] Senior notes: ryanho-psych.md (Alcoholism and psychiatric comorbidity, p.269)

High Yield Summary

Definition: Bipolar disorder = chronic episodic mood disorder with mania/hypomania ± depression. Bipolar I = ≥1 mania. Bipolar II = ≥1 hypomania + ≥1 depression.

Epidemiology: Lifetime risk ~1-4% (spectrum). M=F. Onset ~18y. Diagnosis delayed 5-10y. 1/3 attempt suicide; 10-20% die by suicide. Highly comorbid (substance abuse, anxiety, ADHD).

Aetiology (Multifactorial):

  • Genetics: 79-85% heritability (highest in psychiatry). Shared risk with schizophrenia/autism. Calcium channel, circadian rhythm, neurodevelopmental genes.
  • Neurobiology: Dopamine hyperactivity (mania), serotonergic/noradrenergic deficiency (depression), HPA axis dysregulation, ↓BDNF, structural/functional brain changes (none are specific biomarkers).
  • Environment: Childhood abuse, poor attachment, life events disrupting sleep, childbirth, high expressed emotion (perpetuating).

Clinical Features:

  • Mania (DIG FAST): Distractibility, Irresponsibility/Impulsivity, Grandiosity, Flight of ideas, Activity increase, Sleep ↓, Talkativeness. +/- mood-congruent psychosis. ≥7 days or hospitalisation.
  • Hypomania: Same features but less intense, ≥4 days, NO marked impairment, NEVER psychotic.
  • Bipolar depression: Like MDD but more psychomotor retardation, morning dysphoria, psychotic features, atypical features (hypersomnia, hyperphagia).
  • Mixed features: Manic + depressive features simultaneously → highest suicide risk → responds to valproate.
  • Rapid cycling: ≥4 episodes/12 months. F > M. Check thyroid.

Key Diagnostic Pitfalls: Hypomania missed → diagnosed as MDD → treated with antidepressants alone → manic switch + cycle acceleration. Always take collateral history. Use MDQ/HCL-32.

High Yield Summary

DDx of Manic Presentation (from lecture slides): (1) Depressive disorder with irritability/anxious distress, (2) Psychotic disorder/schizoaffective disorder, (3) Substance/medication-induced or medical conditions (steroids, L-dopa, stimulants, antidepressants, ECT; cocaine, amphetamine; frontal lobe lesion, hyperthyroidism, Cushing's), (4) ADHD, (5) Personality disorder with prominent irritability (esp. BPD).

Key Distinctions:

  • Schizophrenia vs Mania: Psychosis outlasts mood in schizophrenia; mood-incongruent, bizarre delusions; FRS persistent (vs fleeting in mania); loosening of association (vs flight of ideas); chronic course.
  • BPD vs Bipolar: BPD = chronic/trait-like, mood shifts in hours, interpersonal triggers, no grandiosity/↓ sleep; Bipolar = episodic, ↑ energy/grandiosity/↓ sleep.
  • ADHD vs Mania: ADHD = chronic since childhood, no grandiosity/euphoria/↓ need for sleep; Mania = episodic.
  • Organic mania: Always suspect if late-onset, no past Hx, neurological signs.

Misdiagnosis: 69% initially misdiagnosed. Most common error = BP II → MDD (hypomania missed). Delayed 5–7 years. Consequence: antidepressant monotherapy → manic switch + cycle acceleration.

Correct diagnosis requires: Patient history + collateral from informants + screening tools (MDQ, HCL-32) + adherence to diagnostic criteria.

High Yield Summary

Diagnostic Criteria — Key Points:

Manic Episode (Bipolar I): Elevated/expansive/irritable mood + increased energy (both required) + ≥3 associated symptoms (DIG FAST; ≥4 if irritable only) + ≥7 days (or any duration if hospitalised) + marked impairment/psychosis + not substance-induced.

Hypomanic Episode (Bipolar II): Same core + associated symptoms as mania BUT ≥4 days only, NO marked impairment, NEVER psychotic. Observable change in functioning. Bipolar II also requires ≥1 MDE.

ICD-10 vs DSM-5: ICD-10 requires ≥2 mood episodes for bipolar; DSM-5 requires only 1 manic episode for Bipolar I.

Diagnostic Algorithm: History (including collateral) → Screen for past mania/hypomania (MDQ, HCL-32) → Classify current episode → Rule out organic/substance causes → Classify subtype (I/II/cyclothymia) → Apply specifiers → Assess risk.

Baseline Investigations (from lecture slides): CBP, LRFT, TFT, fasting glucose + lipids, 24h CrCl (if renal disease), urine toxicology (if relevant), pregnancy test (if relevant), ECG (if relevant). Purpose: exclude organic mimics + establish baseline before treatment.

Screening Tools: MDQ (13 items, good for BP I), HCL-32 (32 items, better for BP II). Neither replaces clinical interview + collateral history.

High Yield Summary

Acute Mania: Stop antidepressants → Monotherapy (antipsychotic OR valproate OR lithium) → If inadequate, combine (lithium/valproate + antipsychotic) → If still inadequate, re-evaluate dx + ECT. Add short-term BZD for behavioural disturbance. Continue ≥6 months, ≥8 weeks post-remission. Hospitalise all but mildest cases.

Acute Bipolar Depression: Monotherapy (lithium OR lamotrigine OR quetiapine) → Add SSRI/venlafaxine to mood stabiliser if inadequate → ECT if severe/refractory/suicidal. NEVER antidepressant monotherapy. BP II: quetiapine first-line.

Maintenance: Lithium (gold standard, only drug to ↓ suicide), valproate (avoid women of childbearing potential), quetiapine. Lamotrigine for depression-predominant. Psychosocial interventions essential. Continue ≥3 years for lithium; relapse possible even after years of remission.

Key Drug Points:

  • Lithium: narrow therapeutic index (0.6–1.0), monitor levels/RFT/TFT q6mo, anti-suicidal, avoid with thiazides/NSAIDs/ACEi
  • Valproate: NEVER in women of reproductive potential (teratogenic), faster onset than lithium, good for mixed episodes
  • Lamotrigine: good for depression pole, titrate slowly (SJS risk), well-tolerated, ↑ levels with valproate
  • Carbamazepine: potent P450 inducer (drug interactions!), check HLA-B*1502 (SJS), auto-induces own metabolism
  • Quetiapine: versatile (mania + depression + maintenance), metabolic side effects
  • ECT: no absolute C/I, rapid response, use when pharmacotherapy fails or in emergencies

High Yield Summary

Suicide: 1/3 attempt, 10–20% die by suicide. Mixed episodes = highest risk. Lithium is the only mood stabiliser to reduce suicide (80% reduction).

Psychiatric comorbidity: Anxiety (OR 4–11× general population), substance use (OR 3–5×, especially drugs — more common in BD than MDD), sleep disorders, eating disorders, ADHD, personality disorders. Must treat both BD and comorbidities.

Medical complications: CVD/metabolic syndrome (leading non-suicidal cause of death — medication side effects + lifestyle), hypothyroidism (lithium), renal impairment (lithium), hepatotoxicity (valproate), teratogenicity (valproate > carbamazepine > lithium), SJS/TEN (carbamazepine, lamotrigine).

Cognitive decline: Global cognitive deficits. Neuroprogression theory — worse with frequent relapses; increased risk of future dementia. Staging: Stage 1 (high risk/subsyndromal) → Stage 2 (few episodes, good function) → Stage 3 (recurrent episodes, declining function/cognition).

Functional impairment: Functional recovery (43%) lags behind syndromal recovery (98%) — job loss, relationship breakdown, financial ruin, legal consequences, stigma.

Prognosis: Poor. < 20% achieve 5-year stability. Life expectancy ↓13y (M), ↓9y (F). ≥90% have further episodes. 40% relapse within 2 years.

Iatrogenic: Antidepressant monotherapy → manic switch + cycle acceleration (most important avoidable complication). Metabolic syndrome from antipsychotics. Lithium toxicity.

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