How is bipolar disorder diagnosed?

The first step in getting a proper diagnosis is to talk to a doctor, who may conduct a physical examination, an interview, and lab tests. Bipolar disorder cannot currently be identified through a blood test or a brain scan, but these tests can help rule out other contributing factors, such as a stroke or brain tumor. If the problems are not caused by other illnesses, the doctor may conduct a mental health evaluation. The doctor may also 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 conduct a complete diagnostic evaluation. He or she should discuss any family history of bipolar disorder or other mental illnesses and get a complete history of symptoms. The doctor or mental health professionals should also talk to the person's close relatives or spouse and note how they describe the person's 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.¹⁷ Therefore, a careful medical history is needed to assure that bipolar disorder is not mistakenly diagnosed as major depressive disorder, which is also called unipolar depression. Unlike people with bipolar disorder, people who have unipolar depression do not experience mania. Whenever possible, previous records and input from family and friends should also be included in the medical history.