A current problem in the pharmacotherapy of PTSD is that the medication of choice, serotonin re-uptake inhibitors, take several weeks before they show considerable effects on PTSD symptoms. Addition of typical neuroleptics, such as ziprasidone, offers a potential strategy to bring about a faster symptomatic relief, because they display anxiolytic properties without the risk of dependence. Therefore, in addition to standard sertraline therapy (at least 8 weeks), we will give ziprasidone vs. placebo over the first four weeks in a double-blind randomized design.