How is bipolar disorder diagnosed?

Bipolar disorder usually lasts a lifetime. Episodes of mania and depression typically come back over time. Between episodes, many people with bipolar disorder are free of symptoms, but some people may have lingering symptoms.

Doctors diagnose bipolar disorder using guidelines from the Diagnostic and Statistical Manual of Mental Disorders (DSM). To be diagnosed with bipolar disorder, the symptoms must be a major change from your normal mood or behavior. There are four basic types of bipolar disorder:

• 1. Bipolar I Disorder—defined by manic or mixed episodes that last at least seven days, or by manic symptoms that are so severe that the person needs immediate hospital care. Usually, depressive episodes occur as well, typically lasting at least 2 weeks.
• 2. Bipolar II Disorder—defined by a pattern of depressive episodes and hypomanic episodes, but no full-blown manic or mixed episodes.
• 3. Bipolar Disorder Not Otherwise Specified (BP-NOS)—diagnosed when symptoms of the illness exist but do not meet diagnostic criteria for either bipolar I or II. However, the symptoms are clearly out of the person's normal range of behavior.
• 4. Cyclothymic Disorder, or Cyclothymia—a mild form of bipolar disorder. People with cyclothymia have episodes of hypomania as well as mild depression for at least 2 years. However, the symptoms do not meet the diagnostic requirements for any other type of bipolar disorder.

A severe form of the disorder is called Rapid-cycling Bipolar Disorder. Rapid cycling occurs when a person has four or more episodes of major depression, mania, hypomania, or mixed states, all within a year.² Rapid cycling seems to be more common in people who have their first bipolar episode at a younger age. One study found that people with rapid cycling had their first episode about 4 years earlier—during the mid to late teen years—than people without rapid cycling bipolar disorder.³ Rapid cycling affects more women than men.⁴ Rapid cycling can come and go.

When getting a diagnosis, a doctor or health care provider should conduct a physical examination, an interview, and lab tests. Currently, bipolar disorder cannot be identified through a blood test or a brain scan, but these tests can help rule out other factors that may contribute to mood problems, such as a stroke, brain tumor, or thyroid condition. If the problems are not caused by other illnesses, your health care provider may conduct a mental health evaluation or provide a referral to a trained mental health professional, such as a psychiatrist, who is experienced in diagnosing and treating bipolar disorder.

The doctor or mental health professional should discuss with you any family history of bipolar disorder or other mental illnesses and get a complete history of symptoms. The doctor or mental health professional should also talk to your close relatives or spouse about your symptoms and family medical history.

People with bipolar disorder are more likely to seek help when they are depressed than when experiencing mania or hypomania.5 Therefore, a careful medical history is needed to assure that bipolar disorder is not mistakenly diagnosed as major depression. Unlike people with bipolar disorder, people who have depression only (also called unipolar depression) do not experience mania.

Bipolar disorder can worsen if left undiagnosed and untreated. Episodes may become more frequent or more severe over time without treatment.6 Also, delays in getting the correct diagnosis and treatment can contribute to personal, social, and work-related problems.7 Proper diagnosis and treatment help people with bipolar disorder lead healthy and productive lives. In most cases, treatment can help reduce the frequency and severity of episodes.

---

Previous: What are the signs and symptoms of bipolar disorder? Next: What illnesses often co-exist with bipolar disorder?