Revisiting the persistent negative symptoms proxy score using the Clinical Assessment Interview for Negative Symptoms

Area of Science:

• Psychiatry
• Clinical Psychology
• Neuroscience

Background:

• Persistent negative symptoms (PNS) are a core feature of schizophrenia, significantly impacting patient functioning.
• Accurate identification of PNS is crucial for targeted treatment and clinical trial enrollment.
• Existing scales for assessing negative symptoms have limitations.

Purpose of the Study:

• To validate severity cut-off scores on the Clinical Assessment Interview for Negative Symptoms (CAINS) for identifying persistent negative symptoms (PNS).
• To evaluate the diagnostic performance of CAINS in a schizophrenia cohort.

Main Methods:

• 206 schizophrenia patients were assessed using CAINS, with PNS status determined by SANS and SAPS criteria.
• Receiver Operating Characteristic (ROC) curve analysis was employed to identify optimal CAINS cut-off scores.
• Positive Predictive Value (PPV) and Negative Predictive Value (NPV) were calculated.

Main Results:

• Cut-off scores for CAINS total score, Motivation and Pleasure (MAP) subscale, and Expression (EXP) subscale were established as 25, 17, and 5, respectively.
• The CAINS total score demonstrated excellent discrimination between PNS and Non-PNS groups (high Area Under the Curve - AUC).
• The MAP subscale showed better discrimination than the EXP subscale, with high PPV (81.54%) and NPV (97.16%).

Conclusions:

• The validated CAINS cut-off scores provide a reliable method for identifying PNS in schizophrenia.
• CAINS serves as a valuable alternative to existing scales, addressing methodological and conceptual limitations.
• These findings support the use of CAINS in clinical trials for identifying PNS patients.