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
To fail or not to fail __ Clinical trials in depression investigates the causes of the high failure rate of clinical trials in depression research. Apart from the difficulties in the search for new... Show moreTo fail or not to fail __ Clinical trials in depression investigates the causes of the high failure rate of clinical trials in depression research. Apart from the difficulties in the search for new antidepressants during drug discovery, faulty clinical trial designs hinder their evaluation during drug development. This thesis focuses on three important aspects of clinical trials in depression: clinical endpoints, data analysis and trial design-related factors. Show less
In Chapter 2, results of a study are reported in which remitted depressed patients are compared to healthy controls to investigate possible residual cognitive impairments that persist into the... Show moreIn Chapter 2, results of a study are reported in which remitted depressed patients are compared to healthy controls to investigate possible residual cognitive impairments that persist into the euthymic phase. Chapter 3 will describe the effects of an alpha-lactalbumin enriched diet on cognitive performance in unmedicated recovered depressed patients and healthy controls. In Chapter 4 the effects of alpha-lactalbumin on mood and stress-induced cortisol response in unmedicated recovered depressed patients and healthy controls are reported. Chapter 5 describes the effects of low-dose and high-dose ATD on mood and neutral as well as emotional information processing in medicated remitted depressed patients. In Chapter 6, the effects of low-dose and high-dose tryptophan depletion on individual plasma tryptophan levels and the ratio tryptophan/LNAA will be discussed. In Chapter 7 the effects of ATD on heart rate variability in medicated remitted depressed patients are reported. A literature overview of studies investigating the effects of serotonin manipulations on emotional information processing and mood is given in Chapter 8. Also, evidence for a possible sequential link between serotonin induced changes in emotional information processing and mood is evaluated. Chapter 9 contains a summary and integration of the main findings, as well as methodological strengths and limitations, directions for future research and clinical implications of the findings reported in this thesis Show less
Arnold, Ingrid Antonette; Waal, Margaretha Wilhelmina Maria de 2006
De huisarts ziet veel patienten met onverklaarde lichamelijke klachten, vaak in combinatie met angst- en depressieve klachten. Dit proefschrift beschrijft de resultaten van een prevalentie studie... Show moreDe huisarts ziet veel patienten met onverklaarde lichamelijke klachten, vaak in combinatie met angst- en depressieve klachten. Dit proefschrift beschrijft de resultaten van een prevalentie studie met een prospectieve follow-up en een daarop volgende behandelstudie. De prevalentie van somatoforme stoornissen (DSM-IV) was 16,1%: één op de zes patienten die de huisarts bezoekt had tenminste zes maanden last van onverklaarde lichamelijk klachten met aanzienlijke beperkingen. De overlap met angst en depressie was substantieel en vergrootte de ernst van de ziektelast. Deze bevindingen onderstrepen het belang van een brede diagnostiek in de huisartspraktijk die zowel angst en depressie als somatoforme stoornissen omvat. Het aantal symptomen, zowel lichamelijk als psychisch, kan een nuttig instrument zijn bij het identificeren van de ernstigste patiënten. Het gegeven dat bijna driekwart van alle patiënten met een somatoforme stoornis langdurig klachten houdt impliceert een grote behoefte aan behandeling. In een gecontroleerde behandelstudie konden we echter niet aantonen dat een cognitief-gedragsmatige interventie volgens het gevolgenmodel door getrainde huisartsen effectiever was dan gebruikelijke zorg. Aangezien de behandelde patiënten vaak ernstige klachten hadden stellen de auteurs voor om een stapsgewijze behandelmethode te ontwikkelen zodat zowel kortdurende als chronische klachten goed aangepakt kunnen worden. Show less
