Like other mental illnesses, bipolar disorder cannot yet be identified physiologically—for example, through a blood test or a brain scan. A diagnosis of bipolar disorder is made on the basis of symptoms, course of illness, and, when available, family history. The diagnostic criteria for bipolar disorder are described in the Diagnostic and Statistical Manual for Mental Disorders, fourth edition (DSM-IV).

Bipolar disorder is often diagnosed based on the following:

  • Initial assessment—Your doctor will ask about your symptoms: when they started, how long they have lasted, how severe they are, whether you have had them before, and if so, whether the symptoms were treated and what treatment was given. You will also be asked about your medical and family history. In addition, your doctor may wish to interview your family members and/or other persons close to you.
  • Physical exam—Your doctor should give you a thorough physical exam. You may be given several lab tests to rule out other causes for your moods and behavior, such as hyperthyroidism or hypothyroidism . If a physical cause for your symptoms is ruled out, you may be referred to a psychiatrist for a psychological evaluation.
  • Psychological evaluation—After you see your regular doctor, a psychiatrist is probably the best healthcare professional to evaluate your symptoms. Diagnosis of bipolar disorder is based on:
    • Presence of symptoms over time
    • Absence of medications that could cause mood symptoms or medical or neurological illness that may look like bipolar disorder
    • Family history of bipolar disorder

Mania is diagnosed if abnormally elevated mood (lasting at least one week) occurs with three or more of the other symptoms of mania. If your mood is irritable, four additional symptoms must be present.

Depression is diagnosed if depressed mood or loss of interest in pleasure occurs every day (or nearly every day) over the last two weeks, and it is accompanied by five or more of the symptoms.

A diagnostic evaluation may include a mental status exam to determine if your speech, thought patterns, or memory have been affected, as sometimes happens in the case of bipolar disorder.

You may also be evaluated for other psychiatric conditions, such as anxiety disorders and alcohol or drug abuse .