The Negative Symptom Inventory-Psychosis Risk (NSI-PR): Psychometric Validation of the Final 11-Item Version

Area of Science:

• Psychiatry and Mental Health
• Clinical Psychology
• Neuroscience

Background:

• Negative symptoms are key indicators in individuals at clinical high risk (CHR) for psychosis.
• A validated tool for assessing these symptoms in CHR individuals is crucial for early detection and intervention.
• The Negative Symptom Inventory-Psychosis Risk (NSI-PR) was developed following NIMH guidelines.

Purpose of the Study:

• To psychometrically validate the final 11-item version of the NSI-PR scale.
• To assess the scale's reliability and validity in a CHR population.
• To establish the NSI-PR as a reliable measure for psychosis risk research.

Main Methods:

• The study involved 222 participants (144 CHR, 78 controls) across 3 sites.
• Participants completed the 11-item NSI-PR, ecological momentary assessment (EMA), and other validity measures.
• Structural analyses, reliability testing, and convergent/discriminant validity assessments were performed.

Main Results:

• The 11-item NSI-PR demonstrated a robust 5-factor and hierarchical structure.
• The scale showed good internal consistency, temporal stability, and interrater reliability.
• Convergent validity was confirmed with related measures, while discriminant validity was supported by low correlations with other symptom types.

Conclusions:

• The final 11-item NSI-PR possesses sound psychometric properties for CHR individuals.
• The scale is brief, suitable for research and clinical use in early psychosis detection.
• Training materials are available to support multisite trial implementation.