The aim of the current studies was to first determine the convergent validity of several observer and self-report measures of defense mechanisms, and second to determine whether participants in the depressed and anxious groups could successfully be differentiated using observer and self-report measures of defenses. In Study 1, defensive functioning of 150 university students was assessed using the Defense-Q, Defense Mechanism Rating Scale, Defense Style Questionnaire, and the Defense Mechanisms Inventory. The results of the Pearson r analyses indicated that the defense measures were correlated in a theoretically consistent manner at the overall and defense level analyses, with the strongest relations at the mature and immature ends of the scales. Four of the 17 individual defenses were correlated in a theoretically consistent manner. In Study 2, 1182 university students completed the Personality Assessment Inventory and those scoring in the clinical range on depression or anxiety indices were selected for participation in this study. The extent to which these participants could be correctly classified into their respective groups using defense scores from the Defense-Q and the Defense Style Questionnaire was assessed using discriminant analyses. Results indicated that defense scores from both observer and self-report measures can be used to classify participants correctly into depressed and anxious groups. The Defense-Q discriminant function primarily identified depression-related defenses as important for differentiation, whereas the Defense Style Questionnaire discriminant function primarily identified anxiety-related disorders. Confirmatory stepwise discriminant analyses confirmed that the defenses previously identified in the literature were among the most effective in differentiating between the groups. The results from the present investigation identify substantial differences between the defenses assessed by observer and self-report measures and indicate that both methods can be informative for differentiating between depressed and anxious participants.

The aim of the current studies was to first determine the convergent validity of several observer and self-report measures of defense mechanisms, and second to determine whether participants in the depressed and anxious groups could successfully be differentiated using observer and self-report measures of defenses. In Study 1, defensive functioning of 150 university students was assessed using the Defense-Q, Defense Mechanism Rating Scale, Defense Style Questionnaire, and the Defense Mechanisms Inventory. The results of the Pearson r analyses indicated that the defense measures were correlated in a theoretically consistent manner at the overall and defense level analyses, with the strongest relations at the mature and immature ends of the scales. Four of the 17 individual defenses were correlated in a theoretically consistent manner. In Study 2, 1182 university students completed the Personality Assessment Inventory and those scoring in the clinical range on depression or anxiety indices were selected for participation in this study. The extent to which these participants could be correctly classified into their respective groups using defense scores from the Defense-Q and the Defense Style Questionnaire was assessed using discriminant analyses. Results indicated that defense scores from both observer and self-report measures can be used to classify participants correctly into depressed and anxious groups. The Defense-Q discriminant function primarily identified depression-related defenses as important for differentiation, whereas the Defense Style Questionnaire discriminant function primarily identified anxiety-related disorders. Confirmatory stepwise discriminant analyses confirmed that the defenses previously identified in the literature were among the most effective in differentiating between the groups. The results from the present investigation identify substantial differences between the defenses assessed by observer and self-report measures and indicate that both methods can be informative for differentiating between depressed and anxious participants.