Mortality of patients who dropped out from regular lithium prophylaxis: a collaborative study by the International Group for the Study of Lithium-treated patients (IGSLI).

Excess mortality has repeatedly been found in patients with recurrent affective disorders. In previous studies our group has shown that during long-term lithium treatment the mortality of such patients is not significantly higher than that of the general population. In the present study, we extended our investigation to 273 patients from the earlier IGSLI cohort who subsequently dropped out from regular lithium prophylaxis. The standardized mortality ratio (SMR) for the whole group was 2.5, significantly higher (P < 0.01) than 1.0, which is the SMR of the general population. Furthermore, the SMR of the patients from each of the participating countries, namely Denmark, Germany and Austria, was significantly higher than 1.0. These findings strengthen the evidence accumulated in previous investigations that regular long-term lithium treatment does in fact markedly reduce the excess mortality of patients with recurrent affective disorders.