Brain specimens were obtained during routine autopsies conducted at the Allegheny County Medical Examiner's Office after consent was obtained from next of kin. An independent committee of experienced research clinicians made consensus DSM-IV (25 ) diagnoses for each subject using structured interviews with family members and review of medical records (26 (link)), and the absence of psychiatric diagnoses was confirmed in comparison subjects. To control for experimental variance, subjects with schizophrenia or schizoaffective disorder (N=42) were matched individually to one comparison subject for sex and as closely as possible for age (see Table S1 in the data supplement that accompanies the online edition of this article), as previously described (6 (link), 26 (link), 27 (link)), and samples from subjects in a pair were processed together throughout all stages of the study. Some subject pairs had previously been studied for parvalbumin (N=19), somatostatin (N=23), and calretinin (N=19) mRNA levels, mostly by in situ hybridization (see Table S1) (7 (link)–9 (link), 28 (link)). The mean age, postmortem interval, freezer storage time, brain pH, and RNA integrity number (RIN; Agilent Bioanalyzer, Santa Clara, Calif.) did not differ between subject groups (Table 1), and each subject had a RIN ≥7.0. All procedures were approved by the University of Pittsburgh Committee for the Oversight of Research Involving the Dead as well as the university's Institutional Review Board.