Compliance during lithium treatment, intra-erythrocyte lithium variability, and relapse

Differential lithium concentrations across the erythrocyte (RBC) membrane have been studied in the search for biological markers in the affective disorders. The methodologic problems of these studies are reviewed with particular reference to compliance effects. We assessed a triad of compliance parameters, including RBC lithium variability, in a group of 60 lithium clinic attenders, in relation to relapse data and diagnostic subgroups. It was found that RBC lithium variability, used in the present study for the first time, related to higher relapse rates on lithium, suggesting that it may be used as an objective medium term compliance parameter. The established patterns of compliance were compared for the diagnostic subgroups.