Self-reported defence mechanisms as an outcome measure in psychotherapy: a study on the German version of the Defence Style Questionnaire DSQ 40.

The psychoanalytically informed construct of 'defence mechanisms' is of central importance for the understanding of the dynamics of inner conflicts and the onset of neurotic symptoms. Objective and valid assessment of 'defence' is difficult. There are a number of observer rating instruments but only few self-report questionnaires. The German version of the 'Defence Style Questionnaire - DSQ 40' (Andrews, Singh, & Bond, 1993) was examined with regard to its factorial and content validity, and its sensitivity to change during inpatient psychotherapy. One hundred and fifty-five patients with mixed diagnoses were administered the DSQ 40 and the SCL-90-R before and after 3 months of inpatient psychotherapy. Diagnoses were mostly affective and anxiety disorders as well as eating disorders, and there was a high comorbidity of personality disorders. After deletion of some items due to insufficient pairwise item-intercorrelation or false classification to a defence mechanism by experienced clinicians, we found three stable factors of defence (maladaptive, intermediate-neurotic and adaptive) consistent with the previous research. After 3 months of therapy, a decrease in maladaptive mechanisms and an increase in adaptive patterns were found, while neurotic mechanisms did not change on average. Our shortened version of the DSQ 40 was shown to be a valid instrument for the assessment of defence mechanisms and change in these mechanisms after psychotherapy. Our design did not permit an assessment of whether or not the change in defence mechanisms was due to the therapeutic treatment.