Bipolar II Disorder (BD-II)

Bipolar II (BD-II) is a type of bipolar disorder characterized by significant periods of depression, alongside less severe episodes of high energy and mood (hypomania).

Key takeaways

• Bipolar II disorder is a mental health condition involving depressive and hypomanic episodes.

• Unlike mania (associated with bipolar I disorder), hypomania does not significantly impact a person’s daily functioning.

• Several treatment options are available. Medication and psychological therapies are recommended, and , including medication, electroconvulsive therapy may be indicated if medications aren’t effective, and psychological therapies.

Understanding bipolar II disorder

Bipolar II is a mental health condition where a person experiences multiple episodes consisting of severe depression andbut less intense periods of elation (this is called hypomania).^[1]

This contrasts with the more widely known bipolar I subtype. In bipolar I, individuals experience more intense high episodes (called mania) and usually also experience depressive episodes (although they don’t have to for a diagnosis).^[1]

Prevalence of bipolar II

Around 1 in 150, or 40 million people worldwide, are living with a form of bipolar disorder. Over an individual’s lifetime, there is a 2.4% chance of developing a bipolar spectrum disorder.^[2]

The lifetime prevalence of bipolar II (0.4%) is slightly lower than bipolar I (0.6%).^[2]

Symptoms of bipolar II

Bipolar II disorder symptoms can generally be organized into two categories: those experienced during depressive episodes and those during hypomanic episodes. People with bipolar II are often symptom-free between these episodes.

Major depressive episode symptoms

Depressive episode symptoms last for a minimum of 2 weeks, though many people experience them for much longer (often 8 months or more). Common symptoms of depression include:^[3][4]

• Pervasive feelings of sadness (or feeling ‘low’)

• Feelings of guilt or worthlessness

• Tiredness

• Difficulty sleeping or excessive sleeping

• Difficulty concentrating

• Restlessness or lethargic movement

• Appetite changes

• Thoughts of death or suicide

If you or a loved one is struggling with suicidal thoughts, help is available. Contact the 988 Suicide & Crisis Lifeline for immediate support.

Hypomanic episode symptoms

The symptoms of hypomania are similar to those of mania, although they tend to be less severe and last for a minimum of 4 days. Importantly, hypomania symptoms do not cause significant disruption to daily activities (as happens with mania). For this reason, they may be harder to recognize. Common symptoms include:^[3]

• Excessive energy

• Decreased need for sleep

• Racing thoughts

• Fast speech

• Easily distractible

• Increased activity (e.g., working on several projects at once)

• Risky or impulsive behavior (e.g., engaging in high-stakes gambling, reckless driving, or risky sexual behavior)

Causes of BD-II

There is no single cause of bipolar II disorder. Instead, several factors are thought to increase the risk of developing BD-II.^[2][5][6]

• Family history: People with a parent or sibling who has bipolar disorder have an increased chance of developing the condition themselves. 1 out of 3 children who have a parent with a serious mental health condition will develop a mental health problem themselves by the time they are adults.

• Brain development: Research has identified several subtle differences in the brain structure of people with bipolar spectrum disorders. However, these changes are inconsistent and cannot be used for diagnosis on brain scans.

• Stressors: Both adverse childhood experiences (such as abuse) and adult life stressors (for example, divorce or a death in the family) have been linked to an increased risk of developing bipolar II disorder.

• Other mental health conditions: Bipolar II disorder is a commonly occurs co-occurring condition alongside other mental health disorders. People who develop a mood disorder (such as depression) before age 20 are at greater risk of developing bipolar disorder later in life.

Is BD-II genetic?

Studies have shown that bipolar II disorder has a significant genetic component. However, there are no specific gene variants that guarantee the development of BD-II.

Instead, researchers have identified at least 30 genes that increase the risk of developing a bipolar spectrum disorder. This helps to explain the strong familial patterns observed in the condition.^[2]

Prevention

The development of bipolar II disorder cannot be entirely prevented, but avoiding exposure to certain risk factors can lessen the likelihood of its onset:

• Adverse childhood experiences: A stable and safe home environment can reduce the risk of developing several mental health disorders later in life.

• Stressors: Building a strong network and developing coping skills can lessen the mental health impact of stressful life events.

• Economic security and employment: Stable and meaningful employment is considered a protective factor. However, stressful working conditions can have the opposite effect.

Diagnosing bipolar II

A mental health professional can diagnose BD-II based on an assessment of symptoms against the criteria listed in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR).

For a diagnosis of bipolar II disorder, an individual must:^[8]

• Meet the criteria for having experienced both a hypomanic episode and a major depressive episode.

• Hypomanic criteria:

• Abnormally elevated mood for at least 4 days

• Symptoms include inflated self-esteem, decreased need for sleep, excessive talking, racing thoughts, being distractible, an increase in goal-focused activity, and engagement in risky activities.

• The symptoms are noticeable by others and represent a change from normal functioning.

• The symptoms do not cause significant issues with daily function (as with mania) and are not caused by substance use.

• Major depressive criteria:

• Depressed mood and/or loss of interest or pleasure for at least 2 weeks.

• At least 3 further symptoms, including significant weight change, excessive sleep or insomnia, movement agitation or slowing, tiredness, feelings of worthlessness, difficulty concentrating, and recurrent thoughts of death.

• The symptoms cause significant distress or impairment in daily functioning.

• The symptoms are NOT due to the effects of substance use.

• The person has never experienced a manic episode (this would point to a bipolar I disorder diagnosis).

• Another mental health condition could not better explain the symptoms.

Tests and assessments for bipolar II

For a diagnosis of BD-II, an individual will need to be assessed by a suitably qualified mental health professional (usually a psychiatrist). The practitioner will comprehensively review the person’s symptoms, background, general health, and other mental health diagnoses. They may also wish to speak to friends and family to gain insight into symptoms that the individual may not recognize.^[2]

There is no scan or blood test for bipolar disorder. Instead, mental health professionals may use standardized questionnaires to evaluate a person’s symptoms. Commonly used tools include the Mood Disorders Questionnaire and the Hypomania Checklist-32.^[2]

Treatment options for bipolar II

As with many mental health conditions, the evidence for treatment effectiveness can vary depending on individual responses and the severity of the condition. In general, psychiatrists will work with the individual to develop an individualized care plan that addresses the most impactful symptoms of BD-II.

Medication

Medication is not required for everyone with bipolar II disorder. When it is used, some common bipolar II disorder medications include:^[2]

• Lithium: Lithium is a mood-stabilizing drug often used as a first-line treatment for bipolar disorders. Mood stabilizers aim to prevent swings into either depression or hypomania. Due to potential adverse effects, people who take lithium require regular monitoring (including blood tests).

• Other mood stabilizers: Other similar drugs may be used alongside or instead of lithium. These include valproate, aripiprazole, asenapine, olanzapine, quetiapine, and risperidone.

• Antidepressants: Antidepressants may be used to treat BD-II in rare cases. These medications should be used cautiously as there is a risk that they may trigger a hypomanic episode. Common antidepressants include sertraline, citalopram, and fluoxetine.

Psychological therapies

Psychological therapies are unlikely to be effective during active hypomanic or depressive episodes. However, when an individual is feeling well, talking therapies may help build resilience and coping skills to support them during episodes.^[7]

Common talking therapies used to treat bipolar disorders include cognitive behavioral therapy (CBT), interpersonal therapy, and psychoeducation.^[7]

Electroconvulsive therapy

Electroconvulsive therapy (ECT) is a procedure done under general anesthesia, during which low-level electric currents pass through the brain. Although often misunderstood, ECT is considered a safe and effective treatment, with side effects similar to those of taking medication.^[9]

ECT is rarely used to treat bipolar II disorder. However, ECT may be a beneficial treatment for people who experience severe depression that has not responded to treatment with medication.^[2]

Self-management

Bipolar II disorder is a serious mental health condition that cannot be adequately treated without professional support. However, self-management strategies such as symptom education can help an individual to recognize early signs of an episode and seek support promptly.^[5]

Living with bipolar II

Bipolar II can significantly impact multiple aspects of day-to-day functioning. Understanding the lived experiences of individuals with bipolar spectrum disorders is an essential part of supporting people with these conditions.

Living with a bipolar disorder can:^[2]

• Increase the risk of developing another mental health condition.

• Impact employment and educational opportunities.

• Reduce life expectancy due to increased risk of chronic illness, suicide, and accidental death.

• Increase the risk of experiencing stigma and prejudice.

Help is always available. Speak with your healthcare provider to explore support and treatment options. Organizations such as the National Alliance on Mental Illness also offer free support and guidance to people with mental health conditions.