Abstract: A method for treating a medical condition for which quetiapine is indicated in a subject comprises comprising orally administering to the subject quetiapine or a pharmaceutically acceptable salt thereof in a daily dosage amount effective to treat said condition; wherein the quetiapine or salt thereof is administered in one to a plurality of dosage forms collectively comprising (a) a major quetiapine component in immediate-release form in a sedative effective amount, administered not earlier than about 3 hours prior to the start of a sleep period; and (b) either (i) a minor quetiapine component in extended-release, delayed extended-release or delayed pulsed-release form, wherein time of administration and release properties of the minor component provide substantial onset of release of quetiapine therefrom not earlier than about 6 hours after the start of the sleep period, or (ii) a plurality of minor quetiapine components in immediate-release form, administered sequentially during a waking period following th