Mixed anxiety-depressive disorder and major depressive disorder: comparison of the severity of illness and biological variables

Mixed anxiety-depressive disorder (MADD) is a new diagnostic category defin ing patients who suffer from both anxiety and depressive symptoms of limite d and equal intensity accompanied by at least some autonomic features. Pati ents do not meet the criteria for specific anxiety or depressive disorders. The emergence of the symptoms is independent of stressful life events. The re are many issues presently under investigation about the validity of this clinical entity. In this study, a group of 29 patients with MADD was compa red with a group of 31 patients with major depressive disorder (MDD) to ass ess the differences and similarities between these two disease categories i n terms of severity measures and biological variables. The dexamethasone su ppression test (DST) was employed, and thyroid hormones and thyrotropin (TS H) levels were measured for the evaluation of hypothalamic-pituitary-adrena l (HPA) and hypothalamic-pituitary-thyroid (HPT) axes, respectively. The pa tients with MADD were found to be less depressive and more anxious compared to those with MDD. DST responses and thyroid functions were found to be si milar in the two groups. When severity of depression was controlled, k(max) and 2300-h cortisol values were found to be significantly higher in the MA DD group. Although the patients with MDD and MADD presented with relatively different clinical features, there is not enough biological evidence indic ating that MADD represents a discrete diagnostic category. However, there m ay be relatively higher I-IPA activity in MADD patients, (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.