Prediction of clinical course of bipolar manic depressive illness treated with lithium.

A group of bipolar manic depressive patients attending a routine lithium clinic were investigated. The results suggest that, when on treatment with lithium, manic depressive patients with a good prognosis tend to have a higher erythrocyte Na-K ATPase and higher plasma and erythrocyte lithium concentrations than those with a poor prognosis. There was no evidence to suggest that the erythrocyte: plasma lithium ratio was useful in predicting clinical response to lithium therapy. There was also a positive correlation between plasma lithium concentration and Na-K ATPase activity, confirming that in manic depressive subjects lithium produces a rise in erythrocyte Na-K ATPase activity.