Objective. The aim of this study was to investigate the treatment response and optimal maintenance period of antidepressants to minimize the risk of switching in bipolar depression in clinical practice. Methods. In a retrospective chart review, 78 bipolar patients, treated for a depressive episode by adding antidepressant to ongoing mood-stabilizing medications and had been followed for at least 6 months were identified. We determined recovery to euthymia and/or switching into mania during the 6-month follow-up period and estimated the time from antidepressant initiation to mood change. Results. Antidepressants treatment responses were classified into four groups. In one group, depression was sustained for 6 months despite continuous antidepressant treatment (poor-response group, 10.3%). In the second, abrupt switch into mania occurred during antidepressant treatment (acute-switch group, 19.2%). In the third, the depression improved to euthymia without manic switching (good-response group, 50%). In the fourth, the depression improved to euthymia but manic switching occurred during maintenance with antidepressants (delayed-switch group, 20.5%), and the mean duration of antidepressants maintenance was 54.6±38.9 days. Conclusions. Bipolar depression has heterogeneous treatment responses to adjunctive antidepressant. Antidepressants should be discontinued within 8 weeks after improvement to euthymia to minimize the risk of manic switching.
Keywords: Bipolar depression; antidepressants; maintenance treatment; manic switching.