• Clinical science

Bipolar disorder

Summary

Bipolar disorder is a psychiatric illness characterized by episodes of mania (or hypomania) and major depression, interspersed with periods of normal 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 psychosis, and often endanger themselves or others. Depressive episodes are characterized by sadness, anhedonia, and hopelessness. Although episodes of mania or depression can occur anytime, they are especially triggered by environmental factors (e.g., lack of sleep, psychosocial stress). Manic episodes are treated acutely with lithium, antipsychotics, and benzodiazepines. Lithium is also commonly used for long-term treatment, as is valproic acid.

Epidemiology

  • Sex: =
  • The average age of onset is 20 years; the frequency of depressive and manic episodes increases with age.
  • Lifetime prevalence
    • General population: 1–3%
    • First-degree relative with bipolar disorder: up to 10%
    • Monozygotic twin: 40–70%

References:[1][2][3]

Epidemiological data refers to the US, unless otherwise specified.

Etiology

  • Multifactorial origin
    • Strong genetic component → increased risk if first-degree relative is affected (see “Epidemiology” above)
    • ↑ Paternal age → ↑ mutations during spermatogenesis↑ risk of bipolar disorder in offspring
  • Triggers
    • Childhood traumatic experiences
    • Psychosocial stress
    • Sleep disturbances
    • Physical illness

References:[1]

Clinical features

Features of a manic episode, hypomanic episode, or a major depressive episode interspersed with periods of normal mood and functioning

Features of manic and hypomanic episodes

Diagnostic criteria according to DSM-V
Manic episode Hypomanic episode
Core definition
  • Abnormally elevated, expansive, or irritable mood and increased goal-directed behavior not attributable to an organic psychic disorder or psychotropic substances.
Duration
  • Most of the day for at least 1 week
  • Most of the day for at least 4 consecutive days
Criteria
  • ≥ 3 of the following:
    • Increased goal-directed activity (sexually, at work, and/or socially ) or psychomotor agitation
    • Increased talkativeness or pressure of speech
    • Flight of ideas or racing thoughts
    • Loss of social inhibitions, socially inappropriate and reckless behavior, aggressiveness, and hostility
    • Decreased need for sleep
    • Heightened self-esteem or grandiosity
    • Distractibility
Extent of dysfunction
  • Significant dysfunction (work/school), patient requires hospitalization (risk of harm to self or others), or there are psychotic features
  • Does not result in significant dysfunction, hospitalization, or present with psychotic features

The main 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.If psychotic symptoms are present, the episode is, by definition, manic and not hypomanic!

DIG FAST” is an acronym for features of a manic episode: D = Distractibility, I = Irresponsibility, G = Grandiosity, F = Flight of ideas, A = Activity increase, S = Sleep deficit, T = Talkativeness.

Major depressive episode

Diagnostic criteria according to DSM-V
A
  • ≥ 5 symptoms, for at least 2 weeks, with at least one of the symptoms being depressed mood or anhedonia
    • Depressed mood present most of the day, almost every day
    • Sleep disturbance (insomnia or hypersomnia)
    • Loss of interest or anhedonia
    • Feelings of worthlessness or guilt
    • Fatigue or loss of energy
    • Diminished concentration, ability to think, or make decisions (pseudodementia)
    • Weight change due to appetite change
    • Psychomotor changes
    • Suicidal ideation
B
  • Clinically significant distress or impaired functioning in important areas of life (e.g., work, school)
C
  • Not due to effects of psychoactive substances or organic disease
  • In some patients, the initial diagnosis may be a recurrent depressive disorder, as depressive symptoms might be the only symptoms for several years.

SIG E CAPS” is an acronym for the features of major depressive episode: S = Sleep (insomnia or hypersomnia), I = Interest loss (anhedonia), G = Guilt (low self-esteem), E = Energy (low energy or fatigue), C = Concentration (poor concentration or difficulty making decisions), A = Appetite (decreased appetite or overeating), P = Psychomotor agitation or retardation, and S = Suicidality.

References: [4][5][6]

Subtypes and variants

Types of bipolar disorder

In contrast to bipolar II disorder, a history of major depressive episodes is not required for the diagnosis of bipolar I disorder!

Rapid cycling

Cyclothymia

  • Persistent instability of mood involving numerous periods of depression and periods of hypomania
  • Symptoms are not sufficiently severe or persistent enough to diagnose bipolar disorder.
  • 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

Always do a urine drug screening in patients presenting with mania.

References:[7][4]

Diagnostics

All patients must be assessed for suicide risk!

Differential diagnoses

Bipolar I disorder Bipolar II disorder Cyclothymia Substance/medication-induced bipolar and related disorder [8]
Main features
  • Persistent instability of mood involving numerous periods of depression and periods of hypomania
  • Manic or depressive episodes associated with substances/medications

Duration

  • ≥ 2 years
  • Remissions last ≤ 2 months
  • During or soon after substance intoxication/withdrawal, or after exposure to a medication
(Hypo)mania
Depressive episodes
  • May be present or absent
  • ≥ 1 major depressive episode
  • Depressive episode
  • May be present or absent
Psychotic symptoms
  • May be present or absent
  • Absent
  • Absent
  • May be present or absent
Function
  • Significant social or occupational dysfunction
  • May cause significant social or occupational dysfunction during depressive episodes
  • No significant social or occupational dysfunction
  • Significant social or occupational dysfunction

The differential diagnoses listed here are not exhaustive.

Treatment

Acute treatment for mania and hypomania

Antipsychotics are the preferred initial therapy in agitated patients because of their rapid onset of action!

Suicidal patients require immediate management and monitoring to ensure their safety.

Long-term maintenance treatment

In a patient with bipolar disorder, antidepressants should not be used before initiating therapy with mood stabilizers because antidepressants can precipitate a manic episode!

Lithium should not be administered to patients with renal dysfunction! An overdose may result in life-threatening lithium toxicity.

Lithium is the only maintenance drug shown to lower suicide risk.

References:[11][12][13][14][15]