The Relationship Between Serum Lithium Levels and Clinical Response

A guiding principle in the use of lithium salts in the treatment of mental illness is to maintain the serum lithium level between 0.8 and 1.2 mmol/L. This article reviews the limited evidence on which such a recommendation is male. The pharmacokinetics of lithium ion and difficulties inherent in serum lithium estimation are briefly examined. Clinical studies which looked specifically for a relationship between lithium dosage and serum concentration are reviewed. Treatment studies of lithium in mania and prophylaxis of affective disorders are assessed for indirect evidence to support a relationship between favorable therapeutic outcome and recommended serum levels.