A new rating scale for negative symptoms: the Motor-Affective-Social Scale

The commonly used rating scales for negative symptoms in schizophrenia have shown good reliability, but disagreement persists regarding both the content definition and the validity of several items. Instead, authors have recommended rating the specific behaviors that are defined as negative symptoms. To surmount these shortcomings, we developed a new rating scale for negative symptoms: the Motor-Affective-Social Scale (MASS). During a 5-minute structured interview, hand coverbal gestures, spontaneous smiles, voluntary smiling, and questions asked by the interviewer were counted and rated on 101 inpatients with a diagnosis of schizophrenia or schizoaffective disorder. Information on social behavior was obtained from nursing staff. The scale consisted of a total of eight items. The MASS showed high internal consistency (Cronbach alpha coefficient=0.81), inter-rater reliability, and test-retest reliability (intra-class correlation coefficient=0.81). Convergent validity analyses showed high correlations between MASS scores and scores on the Scale for the Assessment of Negative Symptom (SANS), and the negative symptoms subscale of the Positive and Negative Syndrome Scale (PANSS). The MASS showed excellent psychometric properties, practicality, and subject tolerability. Future research that includes the use of the MASS with other patient populations and that investigates the scale's sensitivity during clinical trials should be performed.