 The primary aims of this study are to assess tolerability of ziprasidone dose escalation to 320 milligrams per day mgd compared to continued standard treatment placebo as measured by the Side Effect Checklist, Simpson Angus Scale for Extrapyramidal Symptoms SAS, Barnes Akathisia Scale BAS, serum prolactin concentrations, vital signs, electrocardiogram EKG and completion rates and to assess whether ziprasidone dose escalation improves overall psychopathology compared to continued standard treatment as measured by the change from baseline in the Positive and Negative Syndrome Scale PANSS total score and response rates as defined by a 20 or greater reduction in PANSS total score. 