Bipolar I disorder is primarily defined by manic or mixed episodes that last for at least 7 days, or very severe manic symptoms needing immediate hospital care. The patient also has depressive episodes which may last for at least 2 weeks.
Bipolar II disorder is usually misdiagnosed. It is characterized by occurence of ≥1 major depressive episodes with at least 1 hypomanic episode.
Cyclothymic disorder or cyclothymia is a mild form of bipolar disorder. Patients have  episodes of hypomania alternating with mild depression that lasts for 2 years.
Rapid-cycling bipolar disorder patients have ≥4 episodes of major depression, mania, hypomania or mixed symptoms within a year.


  • Mood disorder characterized by episodic, recurrent and frequently progressive condition of mania, hypomania and major depression
  • Age of onset is between 15 and 30 years old with overall average of 25 years old
  • An estimated 2.4% total lifetime prevalence reported by the World Mental Health Survey across bipolar I, bipolar II & subthreshold bipolar disorder subtypes
  • Associated with increased comorbidity with substance abuse, anxiety disorder, personality disorders and attention-deficit hyperactivity disorder (ADHD)
    • Comorbidity with axis I or axis II may be associated with an earlier age at onset and a worse course of illness

Bipolar Subtypes

Bipolar I

  • Primarily defined by manic or mixed episodes that last for at least 7 days, or very severe manic symptoms needing immediate hospital care
  • Patient also has depressive episodes that may last for at least 2 weeks

Bipolar II

  • Usually misdiagnosed; characterized by occurrence of ≥1 major depressive episodes with at least 1 hypomanic episode

Other Specified Bipolar and Related Disorder or Unspecified Bipolar and Related Disorder

  • Patient has symptoms that do not meet the criteria for either bipolar I or II
    • Symptoms may not last long or are very few

Bipolar Spectrum Disorders

Cyclothymic Disorder or Cyclothymia

  • A mild form of bipolar disorder
  • Patients have episodes of hypomania alternating with mild depression that lasts for 2 years

Rapid-Cycling Bipolar Disorder

  • Patients have ≥ 4 episodes of major depression, mania, hypomania or mixed symptoms within a year
  • More common in patients with severe bipolar disorder, in people who had the disease at an earlier age and in female patients

Signs and Symptoms

Clinical Course
  • Patient may present with bipolar disorder in a manic, hypomanic, depressive or mixed state
  • More common for 1st episode to present as depression
  • Often, the patient will suffer from a number of depressive episodes before a manic episode occurs
  • Features of bipolar disorder vary and can be traced by recording using daily mood chart
  • Patients with bipolar disorder have the highest risk for suicide
    • Knowing risk factors (eg younger age, male, unemployed, early onset of mood disorder) can help in detection of patients who are at risk for suicide


  • Depressive symptoms occur more commonly than manic symptoms throughout the course of illness
    • Bipolar I patients have depression 3 times more frequent than mania
    • Bipolar II patients experience depression 37 times more commonly than hypomania
  • Episodes of depression are similar to unipolar major depression
    • Bipolar depression occurs more commonly in patients with family history of bipolar disorder and in patients with early onset of depression
  • Subsyndromal episodes associated with loss of interpersonal skills andoccupational ability are common in patients with bipolar disorder


  • Extreme behaviors associated with manic episodes often require hospital admission to prevent harm to self and others
  • Acute phase of mania may involve extreme affect, often euphoric or irritable
  • Causes impairment in perception, somatic and social functioning


  • Also have features of mania but at a lesser extent, where insight is preserved
  • Usually accompanied by mild functional impairment
  • Can be assessed using the Hypomania Symptom Checklist (HCL-32), Mood Disorders Questionnaire (MDQ),Young Mania Rating Scale (YMRS)
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