T40. CAN SCHIZOPHRENIA PATIENTS RELIABLY REPORT NEGATIVE SYMPTOMS? A PILOT STUDY USING THE SELF-EVALUATION OF NEGATIVE SYMPTOMS SCALE

Abstract Background Few studies have compared clinical evaluations of negative symptoms to those done by patients. Self-report tools may better reflect the patients’ subjective experience. The Self-Evaluation of Negative Symptoms (SNS; Dollfus et al., 2015), a 20-item scale, was developed to assess the subjective experience of negative symptoms by schizophrenia patients. Dollfus et al (2015) found that the SNS had good psychometric properties and demonstrated that the patients’ ratings were highly correlated with observer ratings. Patients included in the Dollfus et al (2015) study were stable outpatients with a high level of functioning. It remains to be explored whether patients with a lower level of functioning can identify their negative symptoms in a reliable fashion. Our goals were (1) to examine if chronic, low functioning patients can complete the instrument without assistance, potentially providing more immediate insight into their internal perception of negative symptoms and (2) to examine the correlation of their subjective reports with the research assessment of negative symptoms. Methods Stable in- and outpatients who met DSM-5 criteria for schizophrenia spectrum disorder were included in the study. After consenting, patients self-administered the SNS assessment at two time points, separated by one week, with other rater-administered concurrent evaluations: the 16-Item Negative Symptom Assessment (NSA-16), a validated clinical assessment for negative symptoms, the CGI-S, WRAT, BACS, and CDSS. Results A total of 50 subjects with a mean age of 43.71 years (SD = 11.03), 86% male, 64.81% African American, with a mean chlorpromazine equivalency dose of 869.22 (SD = 59.69). Mean premorbid IQ was 79.71 (SD = 17.51) determined by WRAT Standard Total, and BACS Composite T Score mean was 33.56 (SD = 12.11). Cronbach’s coefficient of the SNS (α = 0.903) showed good internal consistency. The intraclass correlation coefficients (ICCs) between SNS time point 1 and SNS time point 2 showed good inter-rater reliability (ICC = .849, 95% CI [.739, .928]. Of the 20 SNS items, significant correlations with the NSA-16 Global Level are reported for only 2 items: “I don’t take any great pleasure in talking with people” (r = 0.65, p < 0.001), and item “I am not interested in having sex, with “Sexual interest” (r = 0.58, p = 0.003). There was a significant difference in the SNS total score between Visit 1 (t(53) = 9.11, p < 0.001) and Visit 2 (t(53) = 8.23, p < 0.001).