Convergent and discriminant validity of overall defensive functioning.

We examined the validity of the construct of overall defensive functioning and its discrimination from standard diagnostic assessments. Within a multisite field trial, patients received intake diagnostic interviews by clinicians who made standard axis I through V diagnoses, then rated defense mechanisms using the Defense Mechanism Rating Scales (DMRS). Patients filled out self-report measures of distress and defenses, the SCL-90-R, and Defense Style Questionnaire (DSQ). Overall defensive functioning (ODF) scales were derived from both the DMRS and the DSQ. Overlap between clinical and self-report ratings of defenses was modest. By two different methods of factor analysis, followed by confirmatory factor analysis, clinical ratings of ODF were clearly discriminable from axis I, axis II personality disorders, current and usual global functioning, and subjective distress. ODF measured by the DSQ was not clearly discriminated from subjective distress ratings, consistent with the hypothesis that subjective distress may distort conscious derivatives of actual defensive processes. The DSQ alone probably should not be considered as a substitute for observer-rated assessment of defensive functioning, although further study of the issue is warranted.