Diagnosis of Bipolar Disorder

Diagnostic Testing in Bipolar Disorder

Bipolar disorder is difficult to diagnose because there is no specific test that confirms the diagnosis. It is important for the person with bipolar disorder to be diagnosed and treated by a mental health care professional as early as possible in order to address issues including:

• Reducing suicide risk
• Reducing the risk of alcohol and/or substance abuse. It is estimated that up to 50% of people with bipolar disorder abuse alcohol or drugs at some time during their illness.
• Reducing risk of marital and work related problems

The response rate to early treatment of symptoms is considerably higher than for later treatment. Misdiagnosis can lead to complications of being treated with improper medications. Some people may go for 10 years without a proper diagnosis. It is also common for a person seeking treatment to see 3-4 doctors before being properly diagnosed.

Part of the difficulty in diagnosing bipolar disorder is that if the first episode is depression, the patient may be incorrectly diagnosed with unipolar depression (depression without bipolar disorder) and not with depression as part of bipolar disorder. Also, if the first episode is hypomania or mania, patients have a positive attitude, feel good, and are full of energy, so they do not seek treatment. When these patients go to the doctor for a depression episode, they rarely report the periods of high energy to the doctor and so are diagnosed with unipolar depression instead of bipolar disorder.

Bipolar disorder is difficult to diagnose in children below the age of 15 because many symptoms strongly overlap with attention deficit hyperactivity disorder (ADHD), a condition often found in adolescents who do not suffer from bipolar disorder. Also, symptoms of bipolar disorder may overlap with symptoms of other disorders, such as anxiety disorders and schizophrenia, which delays proper diagnosis.

Typically the assessment of a patient presenting with symptoms indicative of bipolar disorder consists of a psychiatric evaluation and laboratory tests.

Psychiatric Evaluation

Diagnosis of bipolar disorder is primarily based on the patient's history of behavior patterns and symptoms. Information from family and friends is helpful in establishing the diagnosis since the individual often does not recognize the hypomanic or manic symptoms as abnormal.

A psychiatric evaluation is very important particularly for assessing the patient's level of functioning and the immediate safety to him/herself and others. The doctor may follow a questionnaire called MDQ (Mood Disorder Questionnaire) which is a checklist often used to help identify bipolar-related symptoms. Symptoms are characterized using definitions set out in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR), the manual published by the American Psychiatric Association to establish diagnostic criteria, descriptions and other information for the classification and diagnosis of many types of mental disorders.

During the psychiatric evaluation, the physician will carefully examine three important components, namely the symptoms, the course of the illness, and family history which together determine the diagnosis. In-depth attention will be paid to:

• Risk of suicide
• Number of prior episodes
• Length and severity of each episode
• Time between episodes
• Time elapsed since the last episode
• Description of manic and depressive episodes
• Family history of mood disorders
• Presence of psychotic symptoms
• Cognitive effects of the episodes

Laboratory Evaluation

Although there is no blood test on which to base a diagnosis of bipolar disorder, the following tests enable the physician to rule out other medical problems that could either account for some of the symptoms or complicate the subsequent treatment of bipolar. These blood tests include:

• Complete blood count (CBC)
• Chemistry panel
• Medication levels
• Toxicology screening
• HIV testing
• Thyroid stimulating hormone (TSH)

People with bipolar disorder often have abnormal thyroid function and consequently the National Institute of Mental Health (NIMH) recommends regular monitoring of thyroid levels. Fluctuating thyroid levels can lead to mood and energy changes. This is especially important for people with rapid cycling episodes who may have an increased incidence of co-morbid thyroid problems.