Evaluation of the Reliability of the Scale for Assessment of Negative Symptoms

Reliable and convenient rating scales to assess the negative symptoms ia schizophrenia are necessary to evaluate the theoretical and clinical importance of the distinction between positive and negative symptoms. Although researchers and clinicians have recognised the importance of these symptoms for many years, they were not used in research on schizophrenia till recently. This is probably because of the belief that they are too subjective to be defined with adequate reliability. The researchers have of late expressed renewed interest in the assessment, etiology and the treatment of negative symptoms (Strauss and Carpenter, 1974; Crow, 1980; Andreasen and Oslen, 1982).