What are the DSM V (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition) criteria for diagnosing bipolar disorder?

DSM-5 Criteria for Bipolar Disorder

Bipolar disorder is diagnosed based on the presence of distinct manic, hypomanic, or mixed episodes, with Bipolar I requiring at least one manic episode lasting ≥7 days (or any duration if hospitalization is needed), while Bipolar II requires at least one hypomanic episode (≥4 days) plus at least one major depressive episode. 1

Core Diagnostic Categories

Bipolar I Disorder

• Requires at least one manic or mixed episode lasting at least 7 days, unless hospitalization is required (in which case duration criteria are waived) 1
• The manic episode must represent a significant departure from the individual's baseline functioning 1
• Depressive episodes are NOT required for diagnosis, though most patients experience major or minor depressive episodes during their lifetime 1
• Can be diagnosed based on a single manic episode alone 2

Bipolar II Disorder

• Requires periods of major depression AND hypomania (episodes lasting at least 4 days), with NO history of full manic or mixed manic episodes 1
• The distinction from Bipolar I is critical: hypomania does not cause marked impairment in social or occupational functioning and does not require hospitalization 3
• Bipolar II is especially difficult to diagnose accurately because of difficulty differentiating it from recurrent unipolar depression in depressed patients 2

Episode Characteristics

Manic Episode

A manic episode includes the following features 1:

• Distinct period of abnormally and persistently elevated, expansive, or irritable mood
• Increased energy or activity
• Decreased need for sleep without feeling tired
• Racing thoughts
• Pressured speech
• Grandiosity
• Excessive involvement in pleasurable activities with high potential for painful consequences

Hypomanic Episode

• Similar symptoms to mania but less severe 1
• Duration of at least 4 days 1, 3
• Does NOT cause marked impairment in social or occupational functioning 1, 3
• Does NOT require hospitalization 1, 3
• The key distinction: hypomania often increases functioning, making the boundary between mania and hypomania clearer 3

Mixed Episode

• Period lasting 7 days or more in which symptoms for both manic and depressive episodes are met simultaneously 1
• Involves both elevated mood/increased energy AND depressive symptoms occurring together 1

Depressive Episode

• Often presents with psychomotor retardation and hypersomnia 1, 4
• May include irritability and anger, especially in youth 1
• During depression, patients typically experience hypersomnia (excessive sleep), contrasting sharply with the decreased need for sleep during mania 4

Course Specifiers

Rapid Cycling

• Four or more distinct mood episodes (manic, hypomanic, mixed, or depressive) occurring within a 12-month period 5
• Each episode must still meet full duration criteria: manic episodes ≥7 days (unless hospitalization required) and hypomanic episodes ≥4 days 5
• Not a separate diagnosis but rather a course specifier for bipolar disorder 5

Ultrarapid and Ultradian Cycling

• Ultrarapid cycling: Brief, frequent manic episodes lasting hours to days (but less than 4 days), with 5 to 364 cycles per year 5
• Ultradian cycling: Repeated brief (minutes to hours) mood cycles occurring daily, defined as >365 cycles per year 5

Critical Diagnostic Considerations

Developmental Differences in Youth

• Bipolar disorder in children and adolescents may present differently than in adults, with more irritability, mixed states, and rapid cycling 1
• Changes in mood, energy, and behavior in juvenile bipolar disorder are often more labile and erratic rather than persistent 1
• High rates of comorbidity exist, especially with ADHD and disruptive behavior disorders in youth 1

Essential Assessment Components

• A longitudinal history, rather than solely a cross-sectional assessment, is necessary for accurate diagnosis 1
• Consider changes in energy, activity, and sleep patterns, in addition to mood symptoms 1
• Assess sleep and energy in the context of the developmental period 6

Common Diagnostic Pitfalls

Sleep Pattern Recognition

• If a patient with bipolar depression suddenly stops sleeping, this may indicate a switch to mania or a mixed state, requiring immediate clinical attention 4
• The presence of extended periods without sleep strongly suggests a manic or mixed episode rather than pure depression 4

Mixed States

• Overlooking mixed states can lead to misdiagnosis, as a depressed patient who is also not sleeping may be experiencing a mixed episode rather than pure depression 4
• Mixed depression often has concurrent, usually subsyndromal, hypomanic symptoms 3

Misdiagnosis Risks

• Diagnostic confusion can occur between bipolar disorder and other conditions, particularly in adolescents with psychosis who may be misdiagnosed with schizophrenia 1
• Bipolar II is underdiagnosed in clinical practice; in depressed outpatients, one in two may have Bipolar II 3
• The symptoms of mania and hypomania are the same apart from the presence of psychosis in mania, making the distinction based primarily on severity of impairment 3