A Study of QT and QTc Intervals in Patients Administered Extended Release Paliperidone or Quetiapine

The purpose of this study is to 1) determine whether the effect on QT interval corrected (QTcLD) for heart rate using the population specified linear derived method at steady state is comparable between 12 mg paliperidone extended-release (ER) once daily and that of 400-mg quetiapine administered twice daily, 2) to explore the relationship between the pharmacokinetics of paliperidone ER and electrocardiogram (ECG) parameters of interest, 3) to explore the cardiovascular safety and tolerability of 18 mg paliperidone ER at steady state, and 4) to evaluate the safety and tolerability of all treatments.