Clinical Investigations in Bipolar Disorder and Schizophrenia – Focus on Rating Scales (2005)

Author(s): Cousins DA, Young AH

    Abstract: Psychiatry is the medical specialty concerned with the recognition and management of disorders of the mind. Throughout its history, a tension has existed between the need to define clinical conditions and the desire to describe their causes. This tension is the result of the overlap of descriptive science and explanatory science. The development and use of rating scales can be viewed in light of this dichotomy. Clinical syndromes develop from observations of recurring patterns of presentation, and are in effect constellations of robustly associated symptoms and signs. The core features of a clinical syndrome are that it is reliably present over time, and consistently demonstrable in different situations. It may or may not be associated with a demonstrable pathological process. Pathological diagnoses are often considered to be more valid as they are usually based on objective findings. Although psychiatry has developed favouring the use of descriptive syndromal diagnosis, explanatory models have grown in parallel. Explanations of the cause of psychiatric disorders often reflect the trend in scientific thought and have ranged from religious causes, spiritual explanations, psychodynamic interpretations and the current neuropathological theories. The distinction between the description and the explanation of psychiatric disorders is central to the understanding of the use of rating scales. Clinical scales in psychiatry fall roughly into two groups, those assisting diagnosis and those assessing change in severity of symptoms. This chapter presents the latter. The use of rating scales measuring the presence and change in symptoms increased with the introduction of effective treatments of psychiatric conditions. The push for evidence of effect of treatment resulted in numerous scales being developed to monitor and grade the impact of such treatments on different symptom domains. Consequently, many scales rate aspects of a syndrome rather than improvements as a whole. Those scales that do rate the whole condition are referred to as global scales and can be applied to numerous diagnostic groups. As rating scales have developed to assess different symptom domains, many can appear outmoded or inappropriate for the condition in question. For example, the delineation of positive and negative symptoms of schizophrenia as valid concepts has rendered many older scales ineffective.

      • Book Title: MIMS guide to bipolar disorder and schizophrenia
      • Publisher: Haymarket Medical Imprint
      • Publication type: Book chapter
      • Bibliographic status: Published

        Dr David Cousins
        MRC Clinician Scientist