To assess the effect of risperidone 2 mg daily (QD) on the differential sensitivity of 2 spatial working memory tests (the GMLT and MDR) in non-agitated, drug-naive patients suffering from first-episode schizophrenia/schizophreniform disorder.

Inclusion Criteria:

• Male or female, 18 to 50 years old, antipsychotic-naive, non-agitated patients diagnosed with first-episode schizophrenia or schizophreniform disorder.

Exclusion Criteria:

• Evidence or history of clinically significant medical or non-medical impairment that, in the opinion of the investigator, would affect the safety of the patient or interfere with the evaluation of the trial results;
• Patients who have a history of substance (which included alcohol) dependence within 12 months or abuse within 3 months of enrollment, or tested positive for an illicit drug on the Screening urine toxicology test
• Pregnant or nursing females; females of childbearing potential who are unwilling or unable to use an acceptable method of contraception