Lithium: a brake in the rising cost of mental illness.

Lithium has been extraordinarily successful in the treatment of manic-depression. To compute the economic impact of that success on the United States, an estimate of the cost of care for manic-depression before lithium was introduced was compared with cost estimates after lithium. Economic gains in production were also calculated. Assumptions and exclusions err on the conservative side so that estimates, if inaccurate, are low. The use of lithium as a treatment for manic-depression has saved +2.88 billion in ten years and resulted in a +1.28 billion gain in production, or a conservative total of over +4 billion.