The lithium index in a one-year follow-up.

1. In a one-year follow-up 191 patients on lithium therapy, besides their regular check-ups, were assessed on mood, side-effects and intracellular lithium. 2. The authors were not able to find a correlation between the so called lithium index (i.e. the quotient intracellular lithium/plasma lithium) and the mood score. 3. In the group of patients which used no co-medication at all during the year of the follow-up the authors also failed to find a correlation between the lithium index and some of the clinically most relevant side-effects. However, in that selected group of "only-lithium-using-patients"-only 29 in all-the authors found a remarkable stability in the index value. 4. So even if the authors, in fact, rejected the lithium index estimation as a tool in daily praxis, the authors would once again underline the interesting findings about the so-called lithium index.