Quetiapine is one of atypical antipsychotics with good efficacy and better side effect
profiles than conventional antipsychotics, so it is being widely used beyond the treatment of
schizophrenia. Recently, the BOLDER I and II study showed that quetiapine monotherapy is an
effective and well-tolerated treatment for depressive episodes in bipolar disorder. However,
most c1inicians did not have confidence with quetiapine monotherapy yet, and most practice
guidelines recommend the monotherapy with mood stabilizer as the first-line treatment. The
Korean medication algorithm for bipolar disorder published in 2006 also recommend the
monotherapy with lithium, divalproex, or lamotrigine in the treatment of mild to moderate
depressive episode of bipolar disorder.
Therefore, the aim of this study is investigating the efficacy and safety of quetiapine
monotherapy when compared with mood stabilizer monotherapy. In addition, the investigators
are going to reveal the quality of sleep and quality of life, of the two groups of patients.