Background: It is assumed that the endogenous subtype of depression is a form of depression with various biological abnormalities and a genetic predisposition. The clinical picture rarely shows... Show moreBackground: It is assumed that the endogenous subtype of depression is a form of depression with various biological abnormalities and a genetic predisposition. The clinical picture rarely shows prior stress and/or an abnormal personality. According to the DSM-IV, this subtype is reproduced as the melancholic subtype, but this subtype has insufficient external validity. This is mainly due to the specific operational method used in the categorical DSM system. Question: Reformulating the melancholic subtype by means of a multidimensional approach. This would be formulated and tested on different external validity levels, which should result in better external validity. An improvement at one level of investigation could lead to improvements in relation to other levels, and vice versa. The development of diagnostic concepts could therefore progress according to a cyclic validation process. For this reason, we also investigated whether a later-found subgroup with above-normal plasma AVP could be a more useful endophenotypic parameter as well. This subtype was also tested on different external validation levels. Results: We found a two-dimensionally based, highly anxious retarded subcategory, with better external validation criteria than the melancholic subtype. We also found a second subtype, namely above normal AVP depression, that also had better external validation criteria. Show less
