The Kleinian Psychoanalytic Diagnostic Scale (KPDS) is a psychodiagnostic instrument of assessment based on the psychoanalytical theory of object relations. It was created in order to introduce an intrapsychic and relational dimension into the clinical research on and epidemiology of psychiatric diagnosis. It consists of 15 subscales grouped into the following four dimensions: "Ego Abilities'; "Projective Identification'; "Paranoid-Schizoid'; and "Depressive'. These dimensions constitute different, relatively stable aspects of the mental life of the subject, their demarcation and description permitting the obtention of a chart and profile of the intrapsychic and relational structure. Following several free, unstructured interviews the scale is assessed on the basis of what the subject says and what the rater may detect in the relationship. The inter-rater reliability of the scale, its stability over a time lapse, as well as its internal consistency have all been shown to be high.