Identifying predictors for good lithium response - a retrospective analysis of 100 patients with bipolar disorder using a life-charting method.

PURPOSE: Our aim was to investigate bipolar patients in order to test the validity of various outcome measures and to identify prognostic predictors for pharmacological treatment. MATERIAL AND METHOD: One hundred patients were interviewed using a computerized life-charting program in a descriptive, retrospective analysis. The concept "Burden of illness" was defined as a combination of severity and duration of episodes. Response to treatment was defined as the difference in burden before and after treatment, a low burden during treatment, and freedom of episodes for at least 3 years after insertion of treatment. RESULTS: The absence of mixed episodes and a high initial burden predicted a good response measured as the difference in burden. If remission for 3 years or a low burden during lithium treatment was used, the absence of rapid cycling and of mixed episodes were the most important predictors. The severity of illness before treatment had no impact. DISCUSSION AND CONCLUSION: We suggest the use of absolute measures of severity during treatment as the most appropriate measure of the outcome. Furthermore, our data provide corroboration that treatment with lithium ameliorates the prognosis of the illness, but that mixed episodes and rapid cycling predict a poorer response to lithium.