Intra:Extracellular lithium ratios and clinical course in affective states

Our data suggest that manic or depressed patients may be distinguished from normal individuals or manic-depressives in illness interphase by red blood cell:plasma lithium ratios. The findings also revealed that the intraerythrocyte concentration of lithium was a sensitive index of clinical change and impending toxicity in psychiatric patients, whereas blood lithium alone was not a reliable indicator. Confirmation of these data would contribute to the concept of biologic heterogenicity within the affective illnesses and may influence the procedure of lithium stabilization and chronic maintenance based on monitoring only blood levels of this ion.