Bipolar II Disorder

Bipolar II disorder is a mental health condition involving episodes of depression together with periods of raised mood and energy called hypomania. Hypomania is a clear change from a person's usual state, but it is less severe than the mania seen in bipolar I disorder: it does not involve loss of contact with reality, and it does not cause the same degree of disruption.

For many people, the depressive episodes are the more prolonged and more disabling part of the condition, and they are often the reason someone first seeks help. Because hypomania can feel productive rather than unwell, and may not be recognised as part of an illness, bipolar II disorder is sometimes identified only after depression has been treated for some time.

Bipolar II disorder is not a milder version of bipolar I disorder. The raised mood is less extreme, but the overall burden, particularly from recurrent depression, can be substantial.

It is a long-term condition and it is treatable. Care usually combines medication prescribed and monitored by a clinician with psychological and practical support, aimed at treating episodes and reducing how often they recur.

This page is educational and is not intended to diagnose a mental health condition or replace evaluation by a qualified health professional.

Bipolar II disorder involves two kinds of episode: hypomania and depression.

During a hypomanic episode, commonly recognized experiences can include:

• mood that is elevated, expansive, or irritable, and clearly different from usual;
• increased energy, activity, or productivity;
• needing less sleep without feeling tired;
• talking more or faster than usual;
• thoughts moving quickly between ideas;
• increased confidence; and
• taking on more than usual, or making decisions more readily than usual.

These changes are noticeable to others, but they do not involve losing touch with reality and do not cause the severe disruption seen in mania.

During a depressive episode, experiences can include persistently low mood, loss of interest or enjoyment, fatigue, disturbed sleep, difficulty concentrating, feelings of worthlessness, and thoughts of death or suicide.

Because hypomania may be experienced as feeling well, or simply as being unusually capable, it can go unmentioned. Where a person has had recurring depression, questions about periods of raised mood and reduced need for sleep form part of assessment.

These experiences can also occur in other conditions, and with medication or substance use. This information should not be used as a checklist to diagnose bipolar II disorder.

If you are having thoughts of harming yourself, please see our crisis resources page for how to find urgent support in your location.

There is no single cause of bipolar II disorder, and current understanding describes a combination of biological and environmental influences, broadly similar to those discussed for bipolar I disorder.

Factors discussed in the research and clinical literature include:

• family history of bipolar or related conditions;
• differences in the regulation of mood, energy, and sleep;
• disrupted sleep or routine, which may precede a change in mood;
• significant life stress or major change;
• childbirth and the period following it;
• physical illness and some medications; and
• alcohol, stimulants, and other substances.

A risk factor does not determine that the condition will develop, and its absence does not exclude it.

Because thyroid conditions, other physical illnesses, and medication or substance effects can produce similar changes, assessment usually includes consideration of general health.

Attention to sleep and daily routine, and learning to recognise personal early warning signs, are commonly discussed as part of longer-term management.

Bipolar II disorder is most often confused with major depressive disorder, because people frequently seek help during depression and may not report periods of raised mood. The distinction matters, because treatment for recurrent depression alone may not be appropriate where hypomania has occurred.

It is distinguished from bipolar I disorder by the severity of the raised mood: bipolar I disorder involves at least one manic episode, whereas in bipolar II disorder raised mood occurs as hypomania, without the loss of contact with reality or the degree of disruption seen in mania.

Conditions that may resemble or occur alongside it include anxiety conditions, attention and impulse-related conditions, substance use, and some personality-related presentations where mood varies markedly. Physical causes considered during assessment include thyroid conditions and medication effects.

Assessment therefore looks at the pattern over time rather than a single period, and often draws on information from people who know the person well, since changes during hypomania may be more visible to others.

Bipolar II disorder is treatable, and treatment aims both to address current episodes and to reduce how often they return. Approaches are decided with a qualified health professional and usually continue over the longer term.

Medication has a central role, and the classes used overlap with those used in bipolar I disorder, including mood stabilising and antipsychotic medicines. Because depression is often the dominant difficulty, treatment of depressive episodes receives particular attention; antidepressants are used selectively and with care in bipolar conditions, as in some people they can affect mood stability. Whether any medicine is appropriate, which one, and for how long are decisions for a prescribing clinician together with the person concerned, and usually involve regular review.

Psychological and practical approaches are used alongside medication, commonly including education about the condition, recognising early warning signs, protecting sleep and routine, structured psychological therapy for depression, and support for family members.

Because depressive episodes can be prolonged, continuity of care and regular review tend to matter more than any single intervention.

If difficulties are worsening, or distress feels unmanageable, contact a qualified health professional. If there is immediate risk of harm, see our crisis resources page for how to find urgent support.

MOMD does not provide individual treatment advice and does not recommend starting, stopping, or changing any medication.

System

Diagnostic and Statistical Manual of Mental Disorders (DSM-5-TR)

Classification

Bipolar II Disorder

Category

Bipolar and Related Disorders

Source

Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR)

System

International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM)

Classification

Bipolar II disorder

Code

F31.81

Category

Mental, Behavioral and Neurodevelopmental disorders

Source

International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM)