The topic of psychiatric classification has generated more interest and controversy in the last decade than for a long time. Several trends have coalesced to foster its resurgence as a subject of debate. First, a sociological perspective on psychopathology has gained widespread attention (Becker, 1963; Matza, 1969; Scheff, 1966). The exponents of this perspective have focused on the effects of ‘labelling.’ Their writings have stimulated mental health professionals to examine the consequences of applying classificatory systems in psychiatry. Second, the rapid development of behaviour modification has been a source of numerous polemical attacks on the ‘medical model’ and on the classification system derived from the notion that psychological disturbances constitute a finite number of varieties of mental illness (e.g., Ullmann and Krasner, 1975). Third, criticisms have been voiced of the unsatisfactory reliability of the standard/accepted national and international psychiatric classification schemes (e.g., Scharfetter, 1971; Spitzer and Wilson, 1974). Such criticisms have sparked the development of new classificatory systems notable for the specificity and explicitness of rules of diagnostic assignment (Feighner et al, 1972; Spitzer, Endicott, and Robins, 1974).