Efficacy Study on Cognitive Functions in Schizophrenic Patients

Inclusion criteria

• Diagnosis: DSM-IV schizophrenia (any subtype)
• Duration of illness: ≥ 5 years
• Concomitant standing or prn medications (except other antipsychotics and those contraindicated in the respective package inserts [amisulpride or risperidone]) are permitted during treatment phase, if they were present at a stable dose for at least 6 weeks prior to the start of initial treatment with study medication
• Overall symptom severity: patients must evidence a total score of 60 or higher on the PANSS scale
• Clinical Symptoms: A score of 4 (moderate) or greater on any of the 7 items of the PANSS Positive Symptom Subscale is present
• Cognitive status (minimum performance level): subject must be able to validly complete the baseline MATRICS assessment
• Clinical judgment by the investigator that treatments with amisulpride or risperidone are warranted due to suboptimal clinical outcome despite previous treatments

Exclusion criteria

• Past or current intolerance of amisulpride or risperidone side effects that are judged by the investigator to be unsafe, dose-limiting, or likely to result in study discontinuation.
• Any contraindication for amisulpride or risperidone therapy as indicated in the drug description.
• Presence of any unstable or untreated medical disorder.
• Any history of seizures or seizure disorder other than febrile seizures of childhood;
• History of positive hepatitis B surface antigen.
• Any abnormal laboratory test that is judged to be clinically significant by the investigator.
• A history of significant head injury/trauma, as defined by:

A. loss of consciousness (LOC) for more than 1 hour B. recurring seizures resulting from the head injury C. clear cognitive sequelae of the injury D. cognitive rehabilitation following the injury

• Alcohol or substance dependence within the past 12 months or abuse within the past 3 months. Any subject with positive urine toxicology or alcohol use that is considered abnormal at baseline.
• Clinically significant suicidal or homicidal behavior or attempts within past 6 months.
• Pregnant or breast-feeding women
• Absence of medically approved contraceptive methods for female of childbearing potential.

The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.