Bipolar disorder

Definition

Bipolar disorder is a diagnosable mood disorder marked by distinct episodes of unusually elevated mood (mania or hypomania) that, for most people, alternate with episodes of depression.

The key distinction is between two main forms. Bipolar I is defined by at least one full manic episode, an episode severe enough to cause marked impairment, or to require hospitalization, or to involve psychotic features. Bipolar II is defined by at least one hypomanic episode plus at least one episode of major depression, with no full manic episode ever. Hypomania is real and noticeable, but milder and shorter than mania and without the same level of disruption.

Symptoms and key features

During a manic episode, a person may show:

• elevated, expansive, or irritable mood, present most of the day
• a decreased need for sleep, feeling rested after only a few hours
• grandiosity or an inflated sense of ability or importance
• racing thoughts and rapid, pressured speech
• distractibility and a jump in goal-directed activity or restlessness
• risky behavior, such as overspending, reckless driving, or impulsive decisions

Mania usually lasts about a week or more, though any duration counts if hospitalization is needed. Hypomania involves similar features in a milder form, lasts at least a few days, and doesn't cause the marked impairment that mania does. Depressive episodes look like major depression: low mood, loss of interest, fatigue, changes in sleep and appetite, and difficulty concentrating.

What it looks like

• You go three nights on very little sleep and feel energized rather than tired, taking on far more than usual.
• A burst of confidence leads to a large purchase or a sudden plan that doesn't fit your usual judgment.
• Months later, the energy is gone, replaced by a heavy depression that makes ordinary tasks feel impossible.
• Looking back, you can see the mood came in episodes, not as a steady baseline.

What people often confuse this with

Depression on its own. Many people with bipolar disorder first seek help during a depressive episode, because that's when they feel worst. If past hypomania or mania isn't asked about, the picture can look like major depression alone. This is one of the most common reasons bipolar disorder is missed.

Ordinary mood swings. Everyone has good days and bad days. Bipolar disorder involves sustained episodes that change how a person sleeps, thinks, and behaves, and that differ clearly from their usual self.

A difficult or volatile personality. Bipolar disorder is an episodic illness, not a fixed trait. Between episodes, many people return to a stable baseline.

What research says

Bipolar disorder is well studied, and the treatment evidence is strong.

• Medication is first-line. Mood stabilizers and certain atypical antipsychotics are the foundation of treatment. Lithium has a long track record, and the evidence includes a reduction in suicide risk.
• Antidepressants are used cautiously. Used alone, antidepressants can trigger mania or speed up cycling, so they're prescribed carefully and usually alongside a mood stabilizer.
• Therapy and psychoeducation help. Structured psychotherapy and psychoeducation, including attention to sleep and routine, are valuable additions to medication.
• It's reasonably common. NIMH and large US surveys such as the NCS-R estimate the bipolar spectrum affects roughly 2 to 3 in 100 adults, though any single figure is best read as an estimate.