A tri-ethnic examination of symptom expression on the positive and negative syndrome scale in schizophrenia spectrum disorders.

This study examined differences in symptom expression as measured by the Positive and Negative Syndrome Scale (PANSS [Schizophr. Bull. 13 (1987) 261]) in a tri-ethnic sample of persons diagnosed with schizophrenia. We hypothesized that ethnic differences would be more apparent in Positive Scale symptoms than in Negative and General Scale symptoms of the PANSS. The sample of 351 persons receiving services in community-based mental health clinics came from the initial phase of the San Diego site of the Schizophrenia Care and Assessment Program (SCAP), a longitudinal naturalistic study on the course of schizophrenia treatment. Participants were 88 African-Americans, 198 Euro-Americans, and 65 Latinos. Baseline PANSS scale scores and individual items were analyzed using Multivariate Analysis of Covariance procedures to examine symptoms by ethnic group and living situation while controlling for income, education, and age. There were no significant ethnic differences on the scale scores. At the item level of analysis, significant ethnic group differences were found in Hallucinatory Behavior, Suspiciousness, Excitement, and for Somatic Concerns. The cultural implications for the ethnic differences in each symptom behavior and the need for further research on symptom expression from an ethnographic perspective are discussed.