Two hundred and thirty-five patients with schizophrenia-spectrum disorders were recruited through the University of Iowa Mental Health Clinical Research Center (MHCRC). These subjects participated in various MHCRC research studies approved by the University of Iowa human subjects research review board. All study participants gave written informed consent to undergo research assessments, which included a morphometric magnetic resonance (MR) brain scan, standardized neuropsychological test battery and blood sample for DNA analyses. They were further evaluated using a semi-structured interview instrument, Comprehensive Assessment of Symptoms and History (CASH)(Andreasen, Flaum, & Arndt, 1992), on which schizophrenia (N=221) or schizoaffective disorder (N=14) diagnoses meeting DSM-III-R or DSM-IV criteria were based. All subjects were of Caucasian ancestry. Subjects were relatively young (Mean age=27.9 years (SD=9.44)), and had become psychiatrically ill recently (Mean age of illness onset=24.9 years (SD=8.4); Mean duration of illness=3.2 years (SD=5.7)).
