Key points are not available for this paper at this time.
The Scale for the Assessment of Negative Symptoms (SANS) was developed in order to facilitate evaluation of five important symptoms frequently observed in ‘core schizophrenia’ (process schizophrenia, the schizophrenic defect state, negative schizophrenia). These symptoms include affective flattening, alogia (poverty of speech and thought), avolition, anhedonia, and attentional impairment.
A 1989 study studied this question.