This study intends to compare novel antipsychotics ziprasidone and olanzapine, to confirm the findings of an open study -where stable patients receiving olanzapine switched to ziprasidone- which showed maintenance of clinical effect with improvements in all domains of cognitive function at 6 weeks (Daniel, 1999). Direct comparison of the two agents in a well-controlled double-blind fashion will allow an evaluation of the effect on cognitive function in the short and long-term management of patients with recent-onset schizophrenia, schizoaffective and schizophreniform disorder.