Bipolar Disorder

Description

Alternative Names

Diagnosis

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

Ruling Out Similar Conditions

When making a diagnosis of bipolar disorder, it is important that the physician 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 his or her symptoms, which may be perceived as positive feelings. The physician 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 differentiated by the following characteristics:

• Hypomania persists for at least four days.
• With hypomania most patients are easily distracted and overly talkative.
• With hypomania patients tend not to function very well.

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 bipolar disorder patients 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 an initial fast and good response, which was followed by failure. Furthermore, they were then resistant to other antidepressants.

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

Attention Deficit Hyperactive Disorder (ADHD). Children or adolescents with manic-depressive illness may be inappropriately diagnosed with attention-deficit hyperactivity disorder. ADHD and bipolar disorder often cause inattention and distractibility, and the two disorders may be difficult to distinguish, particularly in children. In some cases, ADHD in children or adolescents can even be a marker for an emerging bipolar disorder. The primary way to differentiate bipolar disorder from ADHD is by the presence of a manic or hypomanic episode, which occurs in patients with bipolar disorder but not with ADHD. Most children with bipolar will also respond to the drug valproate, which does typically work for ADHD.

Schizophrenia. Severe manic episodes that include delusions and hallucinations may be easily confused with schizophrenia. (African-American men, for instance, are more likely to be diagnosed with schizophrenia than with bipolar disorder.) The key factors that distinguish bipolar disorder from schizophrenia are the following:

• The presence of one or more manic or hypomanic episodes in bipolar disorder, but not in schizophrenia.
• A flat emotional expression, with no variability in the voice, among schizophrenics, while people with bipolar disorder are typically very expressive.

Substance Abuse. Up to 60% of bipolar disorder patients abuse alcohol and drugs at some point during their illness. Both diagnosis and treatment are difficult in such cases, since substance abuse is often a method of self-treatment, and withdrawal can produce symptoms of mania or severe depression. The effects of cocaine in a heavy user can also produce abnormal mood swings that closely resemble those of bipolar disorder.

Other Causes of Mood Swings. Other conditions that can cause mood swings include the following:

• Thyroid disorders. Hypothyroidism may be common in bipolar patients, particularly in women. (This condition can be identified with a blood test).
• Adrenal disorders (e.g., Addison's disease or Cushing's syndrome).
• Vitamin B12 deficiency.
• Certain neurologic disorders (e.g., Huntington's disease, epilepsy, brain tumors, encephalitis, or multiple sclerosis).
• A number of medications, including corticosteroids and certain drugs used to treat anxiety and Parkinson's disease can cause mood swings.

Laboratory Tests

The following tests may be helpful:

• Patients should be tested for drugs or alcohol if the physician suspects that they have been using these substances.
• Blood tests for thyroid function should also be taken.

Imaging Tests

Noninvasive imaging tests of the brain using magnetic resonance imaging (MRI) and positron-emission tomographic (PET) scans are being used in clinical trials for detecting abnormalities in the brain that might identify bipolar disorder and test the effectiveness of treatments.