Journal Article

Development and Validation of the Negative Symptom Inventory-Psychosis Risk

Ellman, Lauren M, James, Sydney H, Berglund, Alysia M, Luther, Lauren, Carter, Nathan T, Schiffman, Jason, Gupta, Tina, Pelletier-Baldelli, Andrea, Ristanovic, Ivanka, Strauss, Gregory P, Mittal, Vijay A, Walker, Elaine F

2023

Overview

Abstract Background and Hypotheses Early identification and prevention of psychosis is limited by the availability of tools designed to assess negative symptoms in those at clinical high-risk for psychosis (CHR). To address this critical need, a multi-site study was established to develop and validate a clinical rating scale designed specifically for individuals at CHR: The Negative Symptom Inventory-Psychosis Risk (NSI-PR). Study Design The measure was developed according to guidelines recommended by the NIMH Consensus Conference on Negative Symptoms using a transparent, iterative, and data-driven process. A 16-item version of the NSI-PR was designed to have an overly inclusive set of items and lengthier interview to support the ultimate intention of creating a new briefer measure. Psychometric properties of the 16-item NSI-PR were evaluated in a sample of 218 CHR participants. Study Results Item-level analyses indicated that men had higher scores than women. Reliability analyses supported internal consistency, inter-rater agreement, and temporal stability. Associations with measures of negative symptoms and functioning supported convergent validity. Small correlations with positive, disorganized, and general symptoms supported discriminant validity. Structural analyses indicated a 5-factor structure (anhedonia, avolition, asociality, alogia, and blunted affect). Item response theory identified items for removal and indicated that the anchor range could be reduced. Factor loadings, item-level correlations, item-total correlations, and skew further supported removal of certain items. Conclusions These findings support the psychometric properties of the NSI-PR and guided the creation of a new 11-item NSI-PR that will be validated in the next phase of this multi-site scale development project.

• Publisher: Oxford University Press
• Subject: Anhedonia / Female / Humans / Male / Psychiatric Status Rating Scales / Psychometrics / Psychosis / Psychotic Disorders - diagnosis / Quantitative psychology / Regular / Reproducibility of Results / Schizophrenia - diagnosis