The study will be a randomised controlled, semi-blind (rater-blind) trial with a fixed dosage trial length of nine weeks. Within this nine weeks period study drugs will be given at a dose of 60 mg duloxetine. Patients will be randomized and start medication with duloxetine one week before starting the chronotherapeutic intervention. This is a precaution not to cause any distress in patients (as could be expected with new possible side-effects and the chronotherapeutic intervention introduced at the same time). The following chronotherapeutic intervention covers one week (seven days) where patients will be admitted to an open ward. If improved sufficiently patients can be discharged at this time point.