The Scale for the Assessment of Negative Symptoms (SANS): Conceptual and Theoretical Foundations

Abstract

The Scale for the Assessment of Negative Symptoms (SANS) was the first instrument developed in order to provide for comprehensive assessment of negative symptoms in schizophrenia (Andreasen, 1982, 1983). It consists of five scales that evaluate five different aspects of negative symptoms: alogia, affective blunting, avolition-apathy, anhedonia-asociality, and attentional impairment. Each of these negative symptoms can be rated globally, but in addition detailed observations are made in order to achieve the global rating. It is complemented by a Scale for the Assessment of Positive Symptoms (SAPS), which permits detailed evaluation and global ratings of hallucinations, delusions, positive formal thought disorder and bizarre behaviour (Andreasen, 1984). Taken together, the two scales provide a comprehensive set of rating scales in order to measure the symptoms of schizophrenia and to assess their change over time.