Course of illness and pattern of recurrences in patients with affective disorders during long-term lithium prophylaxis: a retrospective analysis over 15 years.

We analysed the recurrences of 86 patients with monopolar and bipolar mood and schizoaffective disorders treated with lithium over a period of 8.2 years on average in a specialized out-patient clinic. Lithium medication was discontinued by 24% of patients. Diagnosis, age and gender had no influence on the mean morbidity index. Bipolar and schizoaffective patients suffered from more severe recurrences, resulting in hospital admissions, than monopolar patients. A significant decrease in intensity of manic episodes and a significant shortening of depressive episodes was observed over a 10-year treatment period. However, the percentage of manic episodes among all episodes remained constant. There was no indication of a loss of the prophylactic effect in a subgroup of 30 patients who had been treated for a minimum of 10 years. The morbidity index also remained constant over 10 years in the whole sample. Furthermore, the mean lithium blood levels as well as the additional medication in this subgroup could be lowered in the second half of the treatment decade as compared to the initial 5 years.