Initial validation of the Defense Mechanisms Rating Scales Q-sort: A Comparison of Trained and Untrained Raters

Objectives: Defense mechanisms underlie a range of healthy and pathological psychological phenomena and are important mechanisms of change in psychotherapy. Thus, the identification of defense mechanisms in clinical work is crucial, however, measures commonly used for their assessment have various limitations. The Defense Mechanisms Rating Scale Q-set (DMRS-Q; Di Giuseppe, 2014) was developed to address these problems, and to provide an easy-to-use, valid, and reliable tool for the assessment of defense mechanisms. The present study aimed to evaluate the reliability of the DMRS-Q when used by trained versus untrained coders, and to examine the criterion validity of the DMRS-Q in relation to its original observer-rated version, the Defense Mechanisms Rating Scale (DMRS; Perry, 1990). Methods: Collateral sessions (n = 13) with parents of children with externalizing problems were coded with the DMRS-Q by trained and untrained raters, and on the DMRS by an expert rater. Results: We found that both trained and untrained coders were able to assess most defense categories and levels with moderate to excellent reliability on the DMRS-Q, and that untrained coders’ reliability was comparable although slightly lower than untrained coders’ reliability. Moreover, our results indicate the generally good criterion validity of the DMRS-Q when compared to the original DMRS. Discussion: These findings suggest that the DMRS-Q is a promising measure that can be used by clinicians and researchers at all levels of training and with minimal knowledge of defense mechanisms as a reliable and valid method to assess defense mechanisms in clinical settings.