To Your Health
Is lithium safe for a teenager?
A. Since its approval by the U.S. Food and Drug Administration in 1970, lithium has been one of the best documented and most effective drugs for preventing suicide. Lithium is used primarily to treat bipolar affective disorder, also known as manic-depressive illness. Bipolar affective disorder, in which a person's feelings quickly range from well-being to extreme depression and anger, affects almost 6 million adult Americans, including many teenagers. Other drugs are as good or better for treatment of bipolar affective disorder but not as good as lithium in preventing suicide or suicide attempts.
The therapeutic dose for lithium, which may be 450-1,200 milligrams per day, often takes blood levels very close to the toxic range, and requires constant monitoring by a physician.
Lithium was first used in the late 1800s as a remedy for gout, and in combination with other treatments it may still be useful for this purpose. At that time it was also noticed that it stabilized mood. The specific mechanism by which lithium helps bipolar affective disorder is unknown, but it likely involves stabilization of the neurotransmitter glutamate. The level of glutamate in the brain is extremely important, since excessive glutamate can kill brain cells due to overstimulation. Lithium apparently prevents depression from too little glutamate and mania from too much. Other neurotransmitters, such as serotonin and dopamine, are also involved in maintaining mood stability.
Animals fed a low-lithium diet exhibit behavioral abnormalities and give birth to fewer and smaller offspring. In humans, a defined lithium deficiency disease has not been identified, but there are interesting observations of a generally beneficial effect on human behavior from an increased intake of lithium. For instance, researchers have compared Texas counties whose drinking water contained as much as 170 milligrams of lithium per liter (most people drink about a liter of water per day) to counties with little or no lithium in their water. In addition to a lower incidence of suicide, they found the incidences of drug use and other crimes (including homicide, rape, and burglary) were significantly lower.
For Americans who do not live in areas where there is a lot of lithium in the water supply, the average lithium intake is less than 5 milligrams per day. Some clinicians are exploring the benefits of low-dose lithium supplements, in the range of 20-45 milligrams per day, which would not be considered dangerous for most people. Lithium is now available without a prescription in 5-, 10-, and 20-milligram tablets and may be useful in treating alcohol addiction, cluster headaches, and fibromyalgia.
The evidence available at present suggests that adequate lithium intake would provide substantial health and social benefits. Lithium cannot be patented, so no pharmaceutical company will ever consider funneling huge amounts of research dollars into it, and it is unlikely to be approved for any use other than at high doses to treat bipolar affective disorder. However, as long as no health claims are made, lithium in modestly sized tablets will probably continue to be available.