A lithium long-term catamnesis of 124 patients (107 manic-depressive and 17 schizoaffective psychoses) after more than 8 years of lithium prophylaxis led to the following results: 1.) Recovering: 30.3%. Improvement - particularly mitigation of the episodes of illness -: 56%. Lack of efficiency: 13%. Mean incidence of episodes of illness before lithium 0.57 per year, during lithium 0.36. Mean incidence of hospitalisation before lithium 3.4 years, during Lithium 7.1 years. Deterioration following discontinuation of lithium: 21 of 22 cases. 2.) Side effects at the beginning: 61.2%, finally 42.7% (incidence of struma 19.5% of tremor 19%, of polydipsia/polyuria 9.1%). 3.) EEG changes (general slowing-down and dysrhythmia, to a quarter focally accentuated): 59%. 4.) Normal results of haematologic and clinical-chemical investigations (28 parameter) except serum creatinine (10%), creatinine clearance (20.5%) and leucocytosis (13%). The authors discuss the reduced incidence of recovery and the quantity of side effects based on the aspect of long-term catamnesis. Further studies are necessary with regard to the selection of lithium-treated patients, to the duration of prophylaxis without efficiency and to the shift from initial efficiency to later inefficiency.