Bipolar disorder cannot be identified physiologically. That means it cannot be found by things like blood tests or brain scans. It is diagnosed based on symptoms and course of illness. When available, family history plays a role in diagnosis. 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. You will also be asked about your medical and family history. Your doctor may want to interview your family members and/or other people close to you.
• Physical exam—Your doctor will do a physical exam. You may be given several lab tests. These are to rule out other causes for your moods and behavior. Those causes could include 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 will be able 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 could be diagnosed based on an abnormally elevated mood. It must last at least one week. It also must occur with three or more of the other symptoms of mania. If your mood is irritable, four additional symptoms must be present.

Depression is diagnosed based on depressed mood or loss of interest in pleasure. It must occur every day, or nearly every day. This must last two weeks, and be accompanied by five or more of the symptoms.

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

You may also be evaluated for other psychiatric conditions. These include anxiety disorders and alcohol or drug abuse. You will also be evaluated for other potential medical and neurological causes for your symptoms.