Predictors of lithium prophylaxis in bipolar patients

Abstract

Background. This study aimed to investigate the demographical and clinical factors and their predictive powers before and at the end of the 6th and 12th month of lithium prophylaxis. Methods. Subjects meeting the following criteria were included in the investigation: (1) bipolar patients (DSM-IV); (2) having at least a 3-year lithium prophylaxis; (3) being in either the `definite poor' or `definite good' response groups. Both groups were compared regarding sociodemographic and clinical variables. Results. At the pretreatment point of the prophylaxis, four variables that could predict poor response with 74.1% power were severe episodes, higher ratio of mania/depression, psychotic index episode and being unmarried. At the end of the 6th month, the five variables having 84.89% predictive power for poor response were again the previous three variables and additionally bipolar I diagnosis and poor response to the first 6 months of lithium. At the end of the 12th month, the three variables for poor response had 91.37% predictive power and these were again the previous first two variables and a poor response to the first 12 months of lithium. Limitations. This was a retrospective study; psychosocial stress was not evaluated by standardized criteria; and the predictive value of personality disorders could not be tested thoroughly. Conclusions. This study suggests that it is possible to predict, rather reliably, the response to prophylactic lithium regarding clinical variables.