What is Lithium?

Lithium (Li+) is an element that is used as an antipsychotic drug. It treats bipolar disorder and mania, as well as some other psychological diseases like depression as an augmenting agent. The Lithium Test is performed to measure the concentration of lithium in blood.

Lithium is a drug approved by the U.S. Food and Drug Administration (FDA) as an antipsychotic for the treatment of the bipolar disorder. Occasionally, it can be used in other disorders in combination with an antidepressant that does not adequately treat depression. This test measures the amount of lithium in the blood.

Bipolar disorder can affect both adults and children. It is a mental condition marked by alternating periods of depression and mania. These periods may be as short as a few days or weeks or as long as months or years.

During an episode of depression, you may feel sad, hopeless, worthless, and lose interest in daily activities. You may be fatigued but have trouble sleeping, experience weight loss or gain, have difficulty concentrating, and have thoughts of suicide. During a manic episode, you may be euphoric, irritable, have high energy and grandiose ideas, use poor judgment, and participate in risky behaviors. Sometimes you will have mixed episodes with aspects of both mania and depression. Lithium is prescribed to stabilize the mood swings of bipolar disorder. It is often called a “mood stabilizer” and is sometimes prescribed for people with depression who are not responding well to other medications. Less commonly, lithium may be prescribed to prevent disorders with symptoms of schizophrenia (e.g., hallucinations, delusions) and cluster headaches.

Because lithium is a relatively slow-acting drug, its effect on mood may take several weeks. Dosages of the drug are adjusted up or down until blood levels are within a therapeutic range—the blood level range that achieves the desired effect and treats your bipolar disorder. The actual amount of drug that it will take to reach this steady state will vary from person to person and may be affected by your age, general state of health, and other medications that you are taking.

Lithium levels are monitored on a regular basis because lithium has a narrow therapeutic index. This means there is relatively little space between therapeutic and toxic levels. Too little drug and the medication will not be effective. Too many drugs and symptoms of lithium toxicity may develop.

How is the test used?

The lithium test is used to measure and monitor the amount of lithium in your blood so that a healthcare practitioner can determine whether the drug blood level is within the range that will adequately treat your bipolar disorder (therapeutic range). The test may be used to measure blood levels every few days when you first begin taking lithium to help adjust the dose and reach the desired blood level and may also be used at regular intervals or as needed to monitor blood levels. If you start taking additional medications, your healthcare practitioner may order one or more lithium tests to judge the other drugs’ effect, if any, on lithium levels. Lithium tests may also be ordered if toxicity is suspected.