Efficacy of quetiapine XR vs. placebo as concomitant treatment to mood stabilizers in the control of subthreshold symptoms of bipolar disorder: Results from a pilot, randomized controlled trial.

Patients with bipolar disorder (BD) do not always achieve full remission between episodes. Subthreshold symptoms (depressive, manic or mixed) represent a major cause of relapse and disability in these patients. Immediate release (IR) and extended release (XR) formulations of quetiapine are both indicated for short and long-term treatment of BD. The aim of this study was to evaluate the efficacy of quetiapine XR vs placebo in subthreshold symptomatology when added to previous mood stabilizer treatment. A pilot phase IIIB, multicentre, prospective, placebo controlled, randomized, double blinded study of 12 weeks follow-up was performed (NCT01197846). Patients were randomized to quetiapine XR …