Assess the efficacy of once-daily extended release quetiapine fumarate (quetiapine XR) in patients with schizophrenia and depressive symptoms.

12-week, multi-centre, open-label study in adult patients with schizophrenia (D1444C00147). Patients were cross titrated to quetiapine XR over three days (Day 1: 300 mg; Day 2: 600 mg; Days 3-84: 400-800 mg/day [flexible dosing]). Two patient subsets: high depression symptoms (PANSS depression cluster score ≥ 12) and low depression symptoms (PANSS depression cluster score < 12) at baseline. Change from baseline of PANSS total score and PANSS depression cluster score were analysed by subgroup.

Mean (SD) change at Day 84 (LOCF) in PANSS depression cluster score was -4.8 (3.3) for patients with high depression (n=109) and -1.1 (2.7) for patients with low depression (n=362). Mean (SD) change from baseline at Day 84 (LOCF) in PANSS total score was -24.3 (18.5) for patients with high depression and -10.5 (18.0) for patients with low depression. at Day 84: in patients switched to quetiapine XR owing to “lack of efficacy”, mean change (SD) from baseline in PANSS depression cluster score was -5.2 (3.2) and -1.3 (2.8) for patients with high and low depression, respectively; in patients switched due to “insufficient tolerability”, mean change (SD) in PANSS depression cluster score was -4.1 (3.5) and -0.6 (2.5) for patients with high and low, respectively.

Quetiapine XR showed promising results in patients with schizophrenia and depressive symptoms switched from other antipsychotics due to suboptimal efficacy or tolerability. Further randomised, clinical trials are warranted.