Objective: A major barrier to developing treatments for negative symptoms has been measurement concerns with existing assessment tools. Fulfilling the top recommendation of the National Institute of Mental Health's Consensus Development Conference on Negative Symptoms, the Clinical Assessment Interview for Negative Symptoms (CAINS) was developed using an iterative, empirical approach, and includes items assessing motivation, pleasure, and emotion expression. The authors employed multiple analytic techniques to develop the CAINS and here provide final development and validation results.
Method: The CAINS structure, interrater agreement, test-retest reliability, and convergent and discriminant validity were assessed in a large and diverse sample of 162 outpatients with schizophrenia or schizoaffective disorder recruited from four sites.
Results: Three items with poor psychometric properties were removed, resulting in a 13-item CAINS. The CAINS factor structure was replicated, demonstrating two modestly correlated scales: expression (four items) and motivation/pleasure (nine items). The scales demonstrated good internal consistency, test-retest stability, and interrater agreement. Strong convergent validity was demonstrated by linkages with other negative symptom measures, self-report scales of sociality, pleasure, and motivation, and coded facial expressions. Discriminant validity was shown by independence from depression, medication side effects, and cognition. Notably, the CAINS scales were related to real-world vocational, independent living, and social/familial functioning.
Conclusions: The CAINS is an empirically developed and evaluated measure of negative symptoms. Findings indicate that the CAINS is brief yet comprehensive and employable across a wide range of research and clinical contexts.