Symptoms

The PANSS has been ‘the standard’ scale and is frequently adopted as the primary outcome measure in clinical studies for schizophrenia. It is reasonable to assume the more number of items (and the wider the potential score distribution) in a scale, the more likely one would be able to detect a difference but at the cost of time. In order to discern any difference, it might be better to rate as many scales as possible (e.g., all of the PANSS, BPRS, SAPS, and SANS), which nonetheless would be unrealistically time-consuming and in fact has been a case for none of the 150 studies investigated herein.

 

Redundancy within/across the scales is also of concern. For instance, factor analyses of the PANSS have identified several components19 and as such, rating these extracted factors instead of all 30 items might even be sufficient. In line with this view, efforts are ongoing to make simpler rating scales. For instance, The Clinical Global Impression-Schizophrenia scale: CGI-SCH20 is akin to the CGI but it consists of four common symptomatic aspects (i.e., positive, negative, depressive and cognitive symptoms) in addition to global severity/change. This scale has been used in a series of naturalistic, observational investigations (The European Schizophrenia Outpatient Health Outcomes (SOHO) study).21

 

Affective and anxiety symptoms have not been usually assessed with the rating scale in spite of a relatively high prevalence reported in the literature,22 although it might still be possible to capture these problems with such items as depression, guilt feelings, anxiety, and tension in the PANSS for instance. The Montgomery- Åsberg depression rating scale: MADRS23 (10 items) has not been so frequently utilized in this population, and none of the anxiety scales has been commonly used. Another important issue is to evaluate the usefulness of subjective scales for mood and anxiety in patients with schizophrenia.