Efficacy Study of Switching Stabilized Schizophrenic Patients From Conventional to Atypical Antipsychotic Treatment

Double-Blind Long-term Study Comparing the Efficacy and Safety of Olanzapine Versus Haloperidol in Patients With Schizophrenia Previously Stabilized With Conventional Antipsychotic Treatment

The objective of this study is to demonstrate that there is a benefit in switching chronic schizophrenic patients from conventional antipsychotic to olanzapine in terms of efficacy, neurological safety and patient's outcome.

Inclusion Criteria:

Schizophrenic patient meeting the DSM-IV diagnostic criteria more than one year ago and treated with antipsychotic for at least 1 year.

Outpatient (or patient admitted to hospital for social or logistic reasons).

Patient receiving a stable dose of the same conventional antipsychotic for at least 8 weeks before visit 1.

Patient presenting a PANSS score equal or greater than 49 at Visit 2.

Patient considered by the investigator as possible candidates for a switch, owing to inadequate efficacy or poor safety of the current treatment.

Exclusion Criteria:

Patient presenting a schizophreniform or a schizo-affective disorder according to the DSM-IV diagnostic criteria, or any other disorder from Axis I of the DSM-IV, or a disorder from Axis II (limit personality), substance dependence or substance abuse.

Administration of an atypical antipsychotic drug during the 8 weeks preceding V1.

History of resistance to antipsychotic drugs

Hospitalization in a psychiatric unit or in a psychiatric emergency department within the 8 weeks preceding the beginning of the study.

Presence of serious unstable disease, such as a fatal outcome or hospitalization in an intensive care unit, is foreseeable within a period of 6 months.