AstraZeneca has announced important new data presented at the 157th American Psychiatric Association (APA) congress from the first large-scale clinical trial to examine Seroquel (quetiapine) as a treatment for depressive episodes in patients with bipolar I and II disorders. The results show that Seroquel is an effective and well-tolerated agent for the treatment of bipolar depression, and improves a broad range of anxiety and mood symptoms associated with bipolar depression.

Seroquel is currently approved worldwide for the treatment of mania associated with bipolar disorder and schizophrenia.

The results of the study show that Seroquel was superior to placebo in reducing depressive symptoms, as measured by MADRS scores, in patients with bipolar disorder. Patients treated with Seroquel exhibited a statistically significant improvement across all efficacy measures, including those measuring anxiety, as early as week one. The improvements were noted at every assessment during the 8-week trial. In addition, approximately 50 per cent of patients receiving Seroquel achieved remission from their bipolar depression symptoms.

"This study is unique because it is the first to examine Seroquel as a treatment for depressive episodes that included both patients with bipolar I and bipolar II disorders. These results are an important contribution to the scientific community," commented Dr Joseph Calabrese, Co-Director of the National Institute of Mental Health Bipolar Research Center at University Hospitals of Cleveland and Case Western Reserve University School of Medicine, and lead trial investigator. "Based on these exciting results, Seroquel should be further explored in the area of depressive episodes associated with bipolar disorder."

The study, known as the Bolder study, was a double-blind, placebo controlled trial involving 542 patients with bipolar I and II disorders who were randomised to receive 8 weeks of treatment with either a fixed dose of Seroquel, (300mg/d, 600mg/d administered once-daily) or placebo.