Dependence Syndrome: A twenty year validation process
1.1 - Contemporary Changes in Psychopathology
In the last three decades Psychiatry has undergone a major change in its approach to psychopathology. Psychopathological classifications used to reflect belief systems that were based on impressionistic clinical similarities. Most were not grounded in quantifiable data, used unrepresentative populations, and were devoid of a coherent theory (Millon, 1987,1991). The validity of the classifications rested on the personal authority of their originators, which often was limited to a single country (Kendler, 1990). During the sixties there was a growing awareness among clinicians and researchers that the absence of an objective and reliable system for describing psychopathology and for making psychiatric diagnoses was limiting scientific progress (Klerman, 1986). The development of quantitative techniques for measuring psychopathology (i.e. psychometrics) and the refining of standardised diagnostic criteria have led to a transformation of this science.
Psychopathology no longer depends on the intuitive artistry of brilliant clinicians and theoreticians who formulated dazzling but unfalsifiable insights. Psychopathology has acquired a solid footing in the empirical methodologies and quantitative techniques used in psychology (Blashfield, 1986; Millon, 1987). A major innovation was the use of diagnostic criteria that were intended to provide operational definitions of the psychiatric diagnosis. Many instruments were developed in response to the need for a better descriptive diagnosis. These new instruments drew upon existing psychometric methodologies, particularly those for educational testing, with multivariate statistics methods (Blashfield, 1986). The term psychopathology was synonymous with descriptive symptomatology; now, according to Millon (1991), can be justly employed to represent 'the science of abnormal behaviour and mental disorder'.
When investigators evaluate how well a new classification system performs, they rely on the concepts of reliability and validity, concepts that are also used to transform the empirical data collected on psychological processes into psychometric tests.