Bipolar II Disorder
Requires at least one major depressive episode and one hypomanic episode (but no full manic episode).
Etiology (Biopsychosocial Model)
Biological: Similar heritability to Bipolar I; abnormal serotonin/dopamine functioning.
Psychological: Perfectionism, cognitive distortions.
Social: Early trauma, stressful relationships.
Symptoms & Diagnosis (Mnemonic: HIDE ME)
- H - Hypomania (≥4 days, not severe enough to impair)
- I - Impulsivity and increased activity
- D - Depression episodes lasting ≥2 weeks
- E - Energy fluctuations
- M - Mood instability
- E - Exclusion of past manic episode
Treatment
Mood stabilizers: lamotrigine, lithium.
Psychotherapy: CBT, interpersonal and social rhythm therapy.
Antidepressants: Used cautiously (risk of switching to hypomania).
Info
DSM-5-TR Code
F31.81
Prevalence
12-month prevalence: ~0.8% U.S. adults; often underdiagnosed.