Trait anxiety and the effect of a single high dose of diazepam in unipolar depression.

In this cross-sectional study we explored in 101 depressive in-patients (DSM III-R) the association between level of trait anxiety and variables that have been investigated previously to discern primary and secondary depression, respectively. Besides, we explored the influence of trait anxiety level on difference in treatment response to either imipramine or mirtazapine. Trait anxiety was measured interviewing a close relative of the patient using a questionnaire related to aspects of psychic anxiety and to aspects of somatic anxiety. The interviewer focussed on fluctuating anxiety symptoms without persistent mood disturbance during the patient's normal lifelong functioning before developing a depressed mood. We found no relation between trait anxiety level and treatment response to either imipramine or mirtazapine. The most important finding of this study is the significant differential response to the diazepam test: depressive patients with high trait anxiety showed, predominantly, a disappearance of depressive symptoms without sedation and depressive patients with low trait anxiety showed, predominantly, sedation without disappearance of depressive symptoms. The opposite response to the diazepam test in patients with a different history of trait anxiety in spite of similar depressive symptomatology suggests differences in underlying pathophysiologic mechanisms.