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.