Psychotic disorder symptom rating scales: Are dichotomous or multi-point scales more clinically useful?-An ICD-11 field study

Schizophr Res. 2018 Dec;202:254-259. doi: 10.1016/j.schres.2018.07.006. Epub 2018 Jul 13.


Classifications of psychotic disorders are moving towards utilizing dimensional symptom domains as the preferred mechanism for describing psychotic symptomatology. The ICD-11 has proposed six symptom domains (Positive symptoms, Negative symptoms, Depressive symptoms, Manic symptoms, Psychomotor symptoms, and Cognitive symptoms) that would be rated in addition to providing a psychotic disorder diagnosis. This study investigated clinicians' use of dichotomous versus multi-point scales for rating these six domains. Global mental health professionals (n = 273) rated case vignettes using both a 2-point and 4-point version of a rating scale for the six domains. Clinicians were more accurate using the 2-point scale in absolute terms, but after correcting for chance guessing and disagreements, the two versions of the scale were equally accurate. Clinicians believed the 2-point scale would be easier to use, although they also indicated that the 4-point scale would provide richer clinical information. Participants were able to detect the presence of psychotic symptom domains in the vignettes with good reliability with no special training using either scale. We recommend that clinicians and researchers use the version of the scale that best matches their purpose (i.e., to maximize accuracy or enhance case description). Future work should develop the implementation characteristics of the scale to improve its potential for global application.

Keywords: ICD-11; Negative symptoms; Positive symptoms; Rating scale; Schizophrenia.

MeSH terms

  • Attitude of Health Personnel
  • Female
  • Health Personnel
  • Humans
  • Male
  • Middle Aged
  • Psychiatric Status Rating Scales*
  • Psychotic Disorders / diagnosis*
  • Psychotic Disorders / psychology