Definition and Diagnosis
Bipolar Disorder is a mood disorder characterized by episodes of mania or hypomania — periods of abnormally elevated, expansive, or irritable mood and increased energy — that typically alternate with depressive episodes over time.
Epidemiology
Bipolar I and II disorders combined affect roughly 1-2% of the population, with onset commonly occurring in late adolescence or early adulthood. The disorder affects men and women at similar rates, though symptom patterns can differ.
Risk Factors
Family history is one of the strongest risk factors, with heritability estimates among the highest of psychiatric conditions. Sleep disruption, high-stress life events, and substance use can also trigger or worsen mood episodes.
Symptoms and Subtypes
Manic episodes involve elevated mood, decreased need for sleep, grandiosity, rapid speech, and impulsive or risky behavior, while depressive episodes mirror those of MDD. Hypomania involves similar but less severe symptoms that do not cause marked impairment.
Diagnosis
Diagnosis distinguishes Bipolar I (at least one manic episode) from Bipolar II (hypomanic plus depressive episodes, without full mania), based on DSM-5-TR criteria. Careful history-taking is important since bipolar depression can closely resemble unipolar depression.
Treatment
Mood stabilizers such as lithium or certain anticonvulsants, along with atypical antipsychotics, form the foundation of treatment, often paired with psychoeducation and psychotherapy. Regulating sleep and daily routines is an important adjunct to medication management.
Prognosis
Bipolar Disorder is typically a lifelong condition requiring ongoing management, but many individuals achieve significant periods of stability with consistent treatment adherence. Early identification and relapse-prevention planning are associated with better functional outcomes.
Reference
Kaplan, H. I., & Sadock, B. J. (2022). Kaplan & Sadock's Synopsis of Psychiatry (12th ed.). Wolters Kluwer.