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Bipolar II Disorder

Basics

  • Mood disorder with ≥1 major depressive episode and ≥1 hypomanic episode
  • Hypomania: distinct elevated, expansive, or irritable mood with increased energy lasting ≥4 days
  • Hypomania symptoms require 3+ DIG FAST symptoms (4 if mood is only irritable)
  • Excludes history of full manic episode (which would diagnose Bipolar I)

Epidemiology

  • Onset usually 15–30 years
  • Lifetime prevalence 0.5–1%
  • More common in women

Etiology and Pathophysiology

  • Dysregulation of serotonin, norepinephrine, dopamine
  • Heritability >77%
  • Risk factors: genetics, major life stressors, substance misuse

Diagnosis

DSM-5 Criteria

  • ≥1 hypomanic episode (persistently elevated or irritable mood + increased activity/energy)
  • ≥1 major depressive episode
  • Mood disturbance causes clear change in functioning but not severe impairment
  • Hypomanic episode: at least 3 DIG FAST symptoms (Distractibility, Insomnia, Grandiosity, Flight of ideas, Agitation, Speech pressured, Taking risks)
  • Major depression: ≥5 SIG E CAPS symptoms during same 2-week period

History

  • Collateral information important
  • Assess safety: suicidal/homicidal ideation, psychosis
  • Evaluate for substance use and temporal relation to mood symptoms

Mental Status Exam

  • Hypomania: bright appearance, possible psychomotor agitation, pressured speech, euphoria or irritability, distractible thought process, grandiose ideas, no perceptual abnormalities, insight usually stable
  • Depression: unkempt, psychomotor retardation, low/soft speech, sad mood, ruminations, possible hallucinations/delusions, common suicidal ideation, impaired insight

Differential Diagnosis

  • Bipolar I disorder
  • Unipolar depression
  • Personality disorders (borderline, antisocial, narcissistic)
  • ADHD
  • Substance-induced mood disorder
  • Medical causes: epilepsy, brain tumor, infections, stroke, endocrine disease, autoimmune disorders

Diagnostic Tests & Interpretation

  • Mood Disorder Questionnaire (screening)
  • Hypomania Checklist-32 (differentiates BP-II from unipolar depression)
  • PHQ-9 for depression severity
  • Labs: CBC, chem 7, TSH, LFTs, ANA, B12, RPR, HIV, ESR
  • Drug/alcohol screen
  • Brain imaging if late onset or atypical presentation

Treatment

General Measures

  • Ensure safety
  • Psychotherapy: CBT, social rhythm, interpersonal, family-focused
  • Maintain regular sleep and activity patterns
  • Exercise, healthy diet
  • Substance abstinence

Medications

Acute Hypomania (First Line)

  • Quetiapine
  • Lithium

Acute Hypomania (Second Line)

  • Atypical antipsychotics: cariprazine, risperidone, aripiprazole, ziprasidone, asenapine
  • Divalproex (avoid in reproductive-age women)
  • Haloperidol, paliperidone, olanzapine, cariprazine
  • Lithium plus divalproex or atypical antipsychotic combinations

Acute Bipolar II Depression (First Line)

  • Quetiapine
  • Lumateperone

Acute Bipolar II Depression (Second Line)

  • Lithium
  • Lamotrigine
  • Lurasidone
  • Cariprazine
  • Bupropion adjunct
  • Electroconvulsive therapy (ECT)

Medication Monitoring

  • Lithium: monitor plasma levels (0.6–1.2 mmol/L), renal and thyroid function
  • Divalproex: CBC and LFT monitoring; avoid in pregnancy (Category D)
  • Lamotrigine: slow titration to avoid Stevens-Johnson syndrome
  • Atypical antipsychotics: monitor metabolic side effects, EPS, prolactin levels

Cautions

  • Avoid TCAs and SNRIs due to mood cycling risk

Referral

  • Multidisciplinary team: primary care, psychiatry, therapy

Additional Therapies

  • Bright light therapy, TMS, ketamine, vagus nerve stimulation (modest evidence)
  • Blue-blocking glasses or dark therapy for mood elevation
  • Regular sleep/wake cycle

Admission and Nursing

  • Involuntary admission if danger to self/others or inability to meet basic needs
  • Nursing alert for agitation or suicidality, continuous observation if needed

Ongoing Care

  • Regular visits to support adherence
  • Mood charting

Diet

  • Possible benefit from omega-3 fatty acids and probiotics (limited evidence)

Patient Education

  • NAMI: https://www.nami.org/
  • NIMH: https://www.nimh.nih.gov/
  • IBPF: https://ibpf.org/

Prognosis

  • Episode frequency and severity linked to adherence, therapy consistency, sleep, support
  • 25-50% attempt suicide; 15% die by suicide
  • Worse prognosis with substance abuse, unemployment, psychosis, depression, male gender