Bipolar disorder is a psychiatric condition characterized by episodes of mood and functioning. Men and women are equally affected, and there is a strong genetic component to the disease. During manic episodes, patients may experience elevated mood, talkativeness, racing thoughts, and , and can endanger themselves or others. Depressive episodes are characterized by sadness, , and hopelessness. Although episodes of mania or depression can occur at any time, they are especially triggered by environmental factors, such as lack of sleep or psychosocial stress. Manic episodes are treated acutely with , , and . Lithium is also commonly used for long-term treatment, as is .(or ) and major depression, interspersed with periods of normal
- Sex: ♀ = ♂ 
Age of onset 
- The average age of onset is 20 years
- The frequency of depressive and manic episodes increases with age.
- General population: 1–3%
- First-degree relative with bipolar disorder: up to 10%
- Monozygotic twin: 40–70%
Patients with bipolar disorder have a very high risk of suicide.
Epidemiological data refers to the US, unless otherwise specified.
- Multifactorial origin
- Medications (e.g., dexamethasone)
- Childhood traumatic experiences
- Psychosocial stress
- Sleep disturbances
- Physical illness
- Manic/hypomanic episode
- Major depressive episode
“SIG E CAPS:” Sleep (insomnia or hypersomnia), Interest loss (anhedonia), Guilt (low self-esteem), Energy (low energy or fatigue), Concentration (poor concentration or difficulty making decisions), Appetite (decreased appetite or overeating), Psychomotor agitation or retardation, and Suicidality are the features of major depressive episode.
Subtypes and variants
Types of bipolar disorder 
- Bipolar I disorder: at least one episode of mania. Major depressive or hypomanic episodes usually occur but are not required for diagnosis.
- Bipolar II disorder: at least one episode of hypomania and one major depressive episode; no previous episodes of mania (distinguishing feature from bipolar I)
Rapid cycling 
- Patients affected by rapid cycling have 4 or more episodes of depression, mania, or hypomania occurring in a single year.
- Persistent instability of mood involving numerous periods of depressive symptoms and periods of hypomanic symptoms
- Symptoms are not sufficiently severe or persistent enough to diagnose bipolar disorder (symptoms never meet the criteria for a major depressive or hypomanic episode)
- Symptoms last at least 2 years, are present at least half of the time, and are never absent for more than 2 months at a time.
Substance/medication-induced bipolar and related disorder 
- Elevated, disinhibited, or irritable mood with/without depressed mood or anhedonia that develops during or soon after substance intoxication or withdrawal, or after exposure to a medication
- Common precipitants
The diagnosis is clinical and based on the DSM-5 criteria for bipolar disorder. Patients presenting with features of an acute episode should prompt a psychiatry consult and, depending on the severity of the episode, an urgent referral for management.
Suspected bipolar disorder 
- Suspect bipolar disorder in patients presenting with current or previous features of mania/hypomania and/or major depression.
- Consider using screening tools 
- Identify associated features that support the diagnosis, including:
- Suicide attempt
- Onset at an early age
- First-degree relatives with bipolar disorder
- Obtain a detailed clinical history and physical examination; request laboratory studies based on clinical suspicion.
- Rule out differential diagnoses, including:
- Identify coexisting psychiatric conditions and comorbidities that may affect decisions regarding pharmacotherapy.
- Assess the risk of self-injury and consult psychiatry early for a specialized evaluation.
Patients with known bipolar disorder 
- Symptoms suggest an acute episode
- Follow-up visits or visits not related to bipolar disorder
Patients with bipolar disorder have the highest suicide rate among patients with affective disorders. All patients with suspected or confirmed bipolar disorder should be assessed promptly for suicide risk (especially during acute episodes) and evaluated by a psychiatrist. 
Diagnostic studies 
Studies help rule out differential diagnoses and detect conditions that may affect management. A complete history and physical examination should guide the requested studies.
- CBC: may detect anemia 
- BMP, liver chemistries: to establish a baseline before long-term pharmacological treatment
- Thyroid function tests: to rule out
- Additional studies based on the suspected underlying condition (e.g., evaluation for syphilis or frontotemporal dementia)
- Monitoring studies depend on medications (e.g., serum levels of lithium or valproate, liver chemistries; see also “Overview of antipsychotics”).
- ECG: To identify and other heart conditions that may be aggravated by lithium, valproic acid, and antipsychotics
DSM-5 diagnostic criteria for bipolar disorder 
- The DSM-5 diagnostic criteria are used to identify episodes of mania, hypomania, and major depression.
|Manic episode||Hypomanic episode|
|Duration|| || |
|Extent of dysfunction|| || |
A key difference between mania and hypomania is the intensity of the symptoms. Symptoms of mania are much more intense than those of hypomania, result in significant dysfunction, and manic patients often require hospitalization.
Major depressive episodes
|DSM-5 diagnostic criteria for major depressive episode |
|Extent of dysfunction|| |
|Overview of substance/medication-induced bipolar and related disorder|
|Characteristics||Bipolar II disorder||Cyclothymia||Substance/medication-induced bipolar and related disorder |
|Main features|| || || |
| || || || |
|(Hypo)mania|| || |
|Depressive episodes|| || || |
|Psychotic symptoms|| || || || |
|Function|| || || || |
Bipolar and related disorder due to another medical condition
Bipolar and related disorder due to another medical condition is a mood disorder that is diagnosed when a persistent period of abnormally elevated, expansive, or irritable mood and abnormally increased activity or energy is attributable to another medical condition. Possible underlying conditions include:
- Endocrine disorders, e.g., hypercortisolism (Cushing disease)
- Autoimmune disorders, e.g., multiple sclerosis
- Neurological disorders, e.g., stroke, traumatic brain injury, delirium
The differential diagnoses listed here are not exhaustive.
General principles 
- Consult psychiatry before starting treatment.
- Effective treatment combines pharmacotherapy with psychological interventions (e.g., cognitive behavioral therapy).
- Reduce external stimuli.
- Assess symptom severity and for suicidal ideation to determine the appropriate level of care.
Disposition: Often, patients can be managed by a specialist in ambulatory settings; indications for admission are listed below.
- Immediate risk of harm to themselves or others
- Significant psychiatric or medical comorbidities
- No response to ambulatory treatment
- Management of agitation
|Pharmacotherapy for patients with acute bipolar disorder episodes |
|Acute mania ||Mild to moderate |
Patients with suicidal ideation should be admitted immediately for emergency management and monitoring by a specialist.
Acute mania is a psychiatric emergency that requires immediate management.
Lithium has a narrow therapeutic index and doses should be individualized according to serum levels and clinical response; an overdose may result in life-threatening lithium toxicity. Lithium is contraindicated in patients with renal dysfunction. 
Long-term maintenance treatment 
- Indications: Consider for all patients, particularly those with a history of one or more manic episodes.
- Nonpharmacological interventions: an essential part of long-term management associated with better outcomes 
Pharmacotherapy: Consider continuing the drug(s) that resolved the acute manic or depressive episode. ;
- Commonly used agents
- Alternative agents: aripiprazole, olanzapine, carbamazepine, oxcarbazepine
- Refractory or severe bipolar episodes
- Severe depression or predominantly depressive bipolar II disorder: Antidepressants may be started after initiating mood stabilizers.