The study population will be randomized equally to the verum or placebo group at Visit 2. All patients will receive an initial oral course starting with 5mg/d Ziprasidone Hydrochloride or placebo for patients with a body weight ≤ 50 kg and 10 mg/d Ziprasidone Hydrochloride or placebo for patients with a body weight > 50 kg for the first week in the study.