[Psychometric properties of the defense style questionnaire: a reliability and validity study]

To examine the psychometric properties of the Turkish form of the Defense Style Questionnaire (DSQ).

The study included 190 participants, of which 85 with a depressive disorder or obsessive-compulsive disorder diagnosis composed the clinical group, and 105 individuals without any psychiatric diagnosis composed the control group. Participants completed the DSQ, Beck Depression Inventory (BDI), and Trait Anxiety Scale (TAS).

As for the psychometric properties of the DSQ-40, the internal consistency of the mature, neurotic, and immature defense styles was 0.70, 0.61, and 0.83, respectively. Additionally, results revealed that the 3 defense styles had acceptable split-half reliability and test-retest reliability coefficients. Considering the concurrent validity, the mature defense style was negatively correlated with the symptoms of depression and anxiety, whereas the immature defense style was positively correlated with these symptoms. The neurotic defense style, on the other hand, had a positive correlation with anxiety symptoms, but did not reveal a significant correlation with depressive symptoms. The examination of criterion validity revealed results were consistent with our expectations. Significant differences were found in the expected direction between the control and clinical groups.

The psychometric properties of DSQ-40 seem to be quite acceptable; therefore, this questionnaire can be utilized for research purposes.