Diagnosis

Diagnosis

Bipolar disorder is more common than previously thought, but this illness, particularly bipolar disorder II, is still poorly recognized in the family-practice setting. It is estimated that only a third of affected people are accurately diagnosed.

Ruling Out Similar Conditions

When making a diagnosis of bipolar disorder, it is important that the doctor rule out other conditions that may be causing symptoms of bipolar disorder.

Distinguishing Mania from Normal Euphoria or Joy. A major difficulty with a diagnosis of bipolar disorder is the tendency for a patient to be unable to recognize his or her own condition, particularly when in the manic state. The patient often denies their symptoms, which may be perceived as positive feelings. The doctor should take a careful and complete history of any and all episodes of depression, mania, or both. Hypomania, the less severe variant of mania, may be particularly difficult to distinguish from normal joy or euphoria. It can often be distinguished by the following characteristics:

• Hypomania persists for at least 4 days
• Patients with hypomania are easily distracted and overly talkative
• Patients with hypomania have difficulty functioning

Distinguishing Unipolar from Bipolar Depression. People with bipolar disorder are more likely to seek help because of a depressive episode. Indeed, about 16% of people with bipolar disorder do not have a manic episode until they have experienced three or more depressive episodes. In such cases, the condition is often diagnosed as major depression. An accurate diagnosis is important because patients with bipolar disorder who are inappropriately medicated solely with antidepressants have a higher incidence of rehospitalization than do other bipolar disorder patients.

Bipolar disorder should be suspected in patients who have been treated for depression and who had a fast and good response, followed by the return of depression and failure to respond to other antidepressant treatment.

A family history of manic-depressive illness may make a doctor suspicious, but a diagnosis of bipolar disorder cannot be established until a manic or hypomanic episode has occurred. Patients with bipolar II disorder and those with depressive mixed state are most likely to be misdiagnosed with depression.