Sample

• Ten in-patients from the National Institute of Mental Health research wards in Washington, USA
• Study was approved by the review board
• All participants gave informed consent
• Each participant met criteria for chronic Schizophrenia (SZ)
• The participants had been stabilised for at least six weeks on a fixed dose of an anti-psychotic drug (haloperidol)
• In-patients

  Patients who are too ill to live independently in the community
• Patients were clinically stable at the time of the study
• Able to cooperate with the testing procedures
• Free of any illnesses that could have affected blood flow in the brain
• Free of alcohol or drug abuse