Effects of different antidepressant treatments on the core of depression.

Core symptoms of depression are a combination of psychological and somatic symptoms, often combined with psychomotor and cognitive disturbances. Diagnostic classification of depression including the concepts of melancholic, endogenous, or severe depression describe severely depressed patients suffering from most of the core symptoms, together with clinical characteristics of a cyclic unipolar or bipolar course, lower placebo response rates, higher response rates to electroconvulsive therapy, to antidepressant treatments with dually or mixed modes of action, or to lithium augmentation. Higher rates of hypothalamic-pituitary-adrenal axis hyperactivity and specific electroencephalographic patterns have also been shown in this patient group. Summarizing the symptomatology of depression in these patients, a broad overlap between the abovementioned subgroups can be suggested. Because the positive diagnosis of those core symptoms of depression may include clinical consequences, it would be of use to integrate all the mentioned concepts in the upcoming new versions of the diagnostic systems DSM-V and ICD-11.