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.

Inclusion Criteria:

• Duration of illness < 5 years (according to DSM-IV and onset first psychotic episode); CGI severity score > 4 (moderately ill)
• maximum exposure to antipsychotic treatment of =< 16 weeks.

Exclusion Criteria:

• Concurrent treatment with antipsychotic agents =< 12 hours prior to randomization
• for depot agents a period of two weeks or one cycle, whichever is the longer, must occur between last administration and randomization
• Treatment with antidepressants or mood stabilizers =< 7 days of randomization
• for MAOIs and moclobemide this period must =< 2 weeks
• for fluoxetine =< 5 weeks