[Determination of lithium in serum and saliva of patients with manic-depressive disorder].

The slight therapeutic breadth involved means that manic depressive lithium prophylaxis may call for life-long routine management. The lithium/serum-level checks required hitherto are here compared with a non-invasive method, that of determining the lithium level from a mixture of the patient's saliva, a method involving no danger that will eventually assume considerable importance.