[Negative symptoms: clinical and psychometric aspects]

Area of Science:

• Psychiatry
• Clinical Psychology

Background:

• Negative symptoms are increasingly recognized as multidimensional, with evidence for at least two subdomains: diminished expression and amotivation.
• Existing instruments for measuring negative symptoms, such as SANS, PANSS, and NSA-16, vary in domain coverage, informant use, and administration.
• The field is evolving with new instruments developed in response to evolving descriptions of negative symptoms and clinical trial data.

Purpose of the Study:

• To review the evolving landscape of negative symptom assessment in clinical trials.
• To discuss the characteristics and performance of established and emerging negative symptom assessment instruments.
• To highlight the development and preliminary psychometric properties of the Clinical Assessment Interview for Negative Symptoms (CAINS) and the Brief Negative Symptom Scale (BNSS).

Main Methods:

• Review of recent factor analysis studies on negative symptom structure.
• Comparison of domain coverage, informant use, and administration details of SANS, PANSS, and NSA-16.
• Discussion of the development and field testing of CAINS and BNSS in response to NIMH-MATRICS guidelines.

Main Results:

• Factor analysis supports at least two negative symptom subdomains: diminished expression and amotivation.
• Established measures (SANS, PANSS, NSA-16) have limitations in domain coverage and administration.
• New measures, CAINS and BNSS, address five negative symptom domains, differentiate anhedonia aspects, and show promising psychometric properties.

Conclusions:

• Negative symptoms are multidimensional, necessitating refined assessment tools.
• CAINS and BNSS represent advancements in measuring negative symptoms, addressing limitations of older instruments.
• These new scales are valuable for clinical trials and research due to their comprehensive domain coverage and promising psychometric performance.