Bipolar II Disorder Symptoms
Bipolar II disorder is defined by at least one hypomanic episode lasting ≥4 consecutive days and at least one major depressive episode, with no history of full mania. 1
Core Hypomanic Episode Features
Hypomania requires a distinct period of abnormally elevated, expansive, or irritable mood lasting at least 4 consecutive days, representing a clear departure from baseline functioning. 2
The hypomanic episode must include at least three of the following symptoms (four if mood is only irritable): 3
- Grandiosity or inflated self-esteem 3
- Decreased need for sleep (not just less sleep, but feeling rested with less sleep) 3
- Increased talkativeness or pressured speech 3
- Racing thoughts or flight of ideas 3
- Distractibility 3
- Increased goal-directed activity (overactivity in work, social, or sexual domains) 3
- Psychomotor agitation 3
- Excessive involvement in risky activities with high potential for painful consequences 3
Critical Distinction from Mania
The key distinguishing feature is that hypomania does NOT cause marked impairment in social or occupational functioning and does NOT require hospitalization. 2, 3 In fact, hypomania often increases functioning, which paradoxically makes patients less likely to recognize it as problematic. 3
Depressive Episode Characteristics
Depression is the dominant feature of Bipolar II disorder, with depressive episodes outnumbering hypomanic episodes by a ratio of 39:1. 4
Depressive episodes in Bipolar II often present with: 5, 2
- Psychomotor retardation 5, 2
- Hypersomnia (excessive sleeping) 5, 2
- Irritability and anger, especially in younger patients 5
- Mixed features (concurrent subsyndromal hypomanic symptoms during depression) 3
The depressive symptoms typically drive patients to seek treatment, while hypomanic episodes may go unrecognized or unreported. 3
Temporal Patterns and Course
Changes in energy, activity, and sleep patterns are as diagnostically important as mood symptoms themselves. 5
Key temporal features include: 5, 2
- Rapid cycling (≥4 distinct mood episodes within 12 months) is common 2
- Episodes must represent a significant departure from baseline functioning, not just reactive mood changes to stressors 5, 2
- Mood changes occur spontaneously, not solely in reaction to life events 5
Common Diagnostic Pitfalls
Bipolar II is frequently misdiagnosed as major depressive disorder because patients typically present during depressive episodes and fail to report or recognize past hypomanic periods. 4
Critical assessment considerations: 5
- A longitudinal life chart documenting mood patterns over time is essential, not just a cross-sectional assessment 5, 2
- Brief mood swings lasting minutes to hours do NOT meet criteria—hypomania requires ≥4 days duration 5
- Chronic baseline irritability without distinct episodes departing from baseline does NOT constitute hypomania 5
High-Risk Features
Antidepressant-induced mania or hypomania is a specific distinguishing feature of bipolar disorder. 6 If a patient develops manic or hypomanic symptoms after starting antidepressants, this strongly suggests an underlying bipolar diagnosis. 6
Bipolar II carries significant morbidity with completed suicide rates at least equivalent to Bipolar I disorder, despite being perceived as "less severe." 4
Comorbidities to Assess
High rates of psychiatric comorbidities complicate the clinical picture: 2, 4