On the Investigation of the Relationship between Defense Mechanisms and Mental Disorders; Examining Discriminant Validity of the Defense Styles Questionnaire

The 40 question Defense Styles Questionnaire is one of the most famous inventories which have recently been applied. Measurement of validity and reliability is one of the most important activities which need to be performed for assuring of any questionnaire after translating and using it in a new culture or setting. In this research, discriminant validity of Defense Styles Questionnaire has been addressed. A sample of 120 people in form of three clinical groups; depressed, maniac and obsessive and one 30 people group of their companions and friends were selected and answered the DSQ-40 questionnaire. Research results via using a discriminant analysis indicated that 20 defense mechanisms could significantly distinguish these four groups from each other and this success has been 99% in anticipation. Thus, this questionnaire, in terms of psychometric properties particularly in terms of discriminant validity was found to be at an optimal level.