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SOURCE

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Source: Drayton SJ, Fields CS. Bipolar disorder. In: DiPiro JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM, eds. Pharmacotherapy: A Pathophysiologic Approach. 10th ed. New York, NY: McGraw-Hill; 2017. http://accesspharmacy.mhmedical.com/content.aspx?bookid=1861&sectionid=134127982.

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CONDITION/DISORDER SYNONYMS

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  • Manic-depressive illness (or disorder)

  • Manic depression.

  • Mood disorder.

  • Mood swings.

  • Rapid mood cycling.

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DEFINITION

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  • Cyclical, life-long disorder with recurrent extreme fluctuations in mood, energy, and behavior.

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ETIOLOGY

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  • Theoretical causes:

    • Genetic factors.

    • Perinatal insult.

    • Head trauma.

    • Environmental factors.

    • Psychosocial or physical stressors.

    • Sleep dysregulation.

  • Medical conditions that can induce mania:

    • Central nervous system (CNS) disorders.

    • Infections.

    • Electrolyte or metabolic abnormalities.

    • Endocrine or hormonal dysregulation.

    • Drug withdrawal syndromes.

  • Drugs that can induce mania:

    • Alcohol.

    • Antidepressants.

    • Dopamine agonists.

    • Hallucinogens.

    • Norepinephrine-augmenting agents.

    • Steroids.

    • Thyroid preparations.

    • Xanthines.

  • Somatic therapies that induce mania:

    • Bright light therapy.

    • Deep brain stimulation.

    • Sleep deprivation.

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PATHOPHYSIOLOGY

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  • Various theories:

    • Dysregulation between excitatory and inhibitory neurotransmitter systems.

    • Excess of catecholamines (primarily norepinephrine and dopamine) causing mania.

    • Deficiency of gamma aminobutyric acid (GABA) or excessive glutamate activity causing dysregulation of neurotransmitters (eg, increased dopamine and norepinephrine activity)

    • Deficiency of acetylcholine causing imbalance in cholinergic-adrenergic activity.

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EPIDEMIOLOGY

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  • Lifetime prevalence: 1% for bipolar I, 1.1% for bipolar II, and 2.4% of patients with subthreshold bipolar disorder (cyclothymia, unspecified bipolar disorder).

  • Typical onset occurs in late adolescence or early adulthood.

  • Bipolar I disorder occurs equally in men and women; bipolar II disorder more common in women.

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RISK FACTORS

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  • 80–90% of patients have biologic relative with mood disorder.

  • First-degree relatives of bipolar patients have 15–35% lifetime risk of developing any mood disorder and 5–10% lifetime risk for developing bipolar disorder.

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CLINICAL PRESENTATION

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SIGNS AND SYMPTOMS
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  • Manic episode.

    • Usually begins abruptly; symptoms increase over several days.

    • Severe stages may include bizarre behavior, hallucinations, and paranoid or grandiose delusions.

    • Marked functional impairment or need for hospitalization.

    • May be precipitated by stressors, sleep deprivation, antidepressants, CNS stimulants, or bright light.

  • Hypomanic episode.

    • Absence of marked impairment in social or occupational functioning, delusions, and hallucinations.

    • Patients may be more productive and creative than usual during episodes, but 5–15% rapidly switch to manic episode.

  • Major depressive episode.

    • Patient in bipolar depression often has mood lability, hypersomnia, low energy, psychomotor retardation, cognitive impairments, anhedonia, decreased sexual activity, slowed speech, carbohydrate craving, and weight gain.

    • Delusions, hallucinations, and suicide attempts more common in bipolar depression than unipolar depression.

  • Mixed episode.

    • Occurs in up to 40% of all episodes, often difficult to diagnose and treat, and more common in younger and older patients and women.

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DIAGNOSIS

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MEANS OF CONFIRMATION AND DIAGNOSIS
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  • Classification of bipolar disorders:

    • Bipolar I: manic episode with or without major depressive or mixed episode.

    • Bipolar ...

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