Trait anxiety and defensive functioning in relation to antidepressant treatment outcome

Depression can occur in patients with or without trait anxiety. Although it is assumed that assessment of defenses can be useful in planning biological treatment, no studies have confirmed this hypothesis. In this study we focus on the relation between trait anxiety and defensive functioning, and on the combined influence of these personality characteristics on response to antidepressants among inpatients with a major depressive episode.

Major depressive episode was diagnosed using the Schedule for Affective Disorders and Schizophrenia (SADS) and the severity of the depression was measured with the Hamilton Rating Scale for Depression (HAM-D). The level of trait anxiety was assessed using a questionnaire with 34 questions pertaining to trait anxiety. The Defense Style Questionnaire (DSQ 88) was used to assess defensive functioning followed by a weighted overall defensive functioning score (ODF). Partial correlations and multiple regression analyses were used to analyze the data.

The final sample included 85 patients. A significant negative effect of trait anxiety by ODF (p: 0.000) was found on the outcome score, i.e. the combination of a high score on trait anxiety and a low score on the ODF resulted in a significantly higher final score on the HAM-D.

The most important finding in this study is that the combination of a high level of trait anxiety and immature defensive functioning evidently had a negative effect on antidepressant treatment outcome.