The BOLDER II study shows that quetiapine has potential as monotherapy for acute bipolar depression, according to a presentation at the annual meeting of the American Psychiatric Association. The BOLDER II Study randomized a total of 509 patients, 59 percent of whom completed the study.

From the first week of the BOLDER II (BipOLar DEpRession) study, improvements in severity of depressive symptoms (MADRS total scores) were significantly greater with quetiapine 300 and 600 mg daily than with placebo (week 1, change from baseline with quetiapine 300 and 600 mg/day, -9.42 and -9.14, respectively; versus -6.10 for placebo).

Significant differences in improvement continued during the eight-week study (week 8, change from baseline with quetiapine 300 and 600 mg/day, -16.94 and -16.00 respectively; versus -11.93 for placebo).

The new data support the findings of the previously reported BOLDER I study. Together, the studies represent one of the largest placebo-controlled investigations ever conducted for the acute treatment of bipolar depression.

In an analysis of BOLDER I and BOLDER II data (1045 patients), suicidal thoughts (MADRS item 10 score) decreased significantly more with quetiapine at both doses than with placebo. In a similar analysis of anxiety symptom scores, symptoms improved significantly more in patients treated with quetiapine at both doses compared to placebo.

In addition, a sub-group analysis of bipolar disorder II patients from the BOLDER I and BOLDER II studies found that improvement in severity of depressive symptoms (mean MADRS total score) from baseline was significantly greater with quetiapine than with placebo, from Week 1 through Week 8.

"Results from BOLDER II are remarkably similar to those found in BOLDER I, the first large-scale study that examined SEROQUEL treatment of depressive episodes in bipolar I and II patients. The replication of BOLDER I by BOLDER II adds considerable strength to the BOLDER data," said Michael E. Thase MD, of the Department of Psychiatry at University of Pittsburgh Medical Center, USA and principal investigator of BOLDER II. "In the past, doctors have typically treated bipolar disorder with both a mood stabilizer and an antidepressant. Having a single medication to treat both the manic and depressive episodes of this condition would be a significant medical advance."

Professor Joseph Calabrese, co-director of the National Institute of Mental Health Bipolar Research Center at University Hospitals of Cleveland and Case Western Reserve University said the fact that a study on the scale of BOLDER II replicates the findings of BOLDER I so closely is both remarkable and exciting, offering the hope of similar consistency in the real-world setting.

"As a clinician, when you treat someone with bipolar depression you ask yourself -- what can I do to reduce the chance of this person committing suicide; how can I get symptoms under control to give them a better quality of life; and finally, will they be satisfied with the treatment and continue taking it? The results of the BOLDER study suggest that medical science can help us answer these questions better in the future."