Filtern
Dokumenttyp
Sprache
- Englisch (5) (entfernen)
Volltext vorhanden
- ja (5) (entfernen)
Schlagworte
- Depression (5) (entfernen)
Institut
- Psychologie (4)
- Fachbereich 1 (1)
There is considerable evidence for an association between chronic dysregulation of the hypothalamus-pituitary adrenal (HPA) axis, atrophy of the hippocampus (HC) and cognitive and mood changes in clinical populations and in aging. The present thesis investigated this relationship in young healthy male subjects. Special emphasis was put on measures of HC volume and function derived from structural and functional magnetic resonance imaging (MRI). Higher cortisol levels after awakening were observed in subjects with higher levels of depressive symptomatology. Larger HC volume was associated with higher cortisol levels after awakening and in response to acute stress, whereas cognitive performance was impaired in subjects with larger HC volumes. Hippocampal activation during picture encoding was reduced after stress induction, and positive associations between activation and cognitive performance before stress were not present anymore afterwards. The present findings underscore the importance of structural and functional brain imaging for psychoneuroendocrinological research. The investigation of the association between cortisol levels and hippocampal integrity in young healthy subjects elicited unexpected results and adds to the understanding of HPA dysfunction and HC atrophy in clinical and aged populations.
The role of cortisol and cortisol dynamics in patients after aneurysmal subarachnoid hemorrhage
(2011)
Spontaneous aneurysmal subarachnoid hemorrhage (SAH) is a form of stroke which constitutes a severe trauma to the brain and often leads to serious long-term medical and psychosocial sequels which persist for years after the acute event. Recently, adrenocorticotrophic hormone deficiency has been identified as one possible consequence of the bleeding and is assumed to occur in around 20% of all survivors. Additionally, a number of studies report a high prevalence of post-SAH symptoms such as lack of initiative, fatigue, loss of concentration, impaired quality of life and psychiatric symptoms such as depression. The overlap of these symptoms and those of patients with untreated partial or complete hypopituitarism lead to the suggestion that neuroendocrine dysregulations may contribute to the psychosocial sequels of SAH. Therefore, one of the aims of this work is to gain insights into the role of neuroendocrine dysfunction on quality of life and the prevalence of psychiatric sequels in SAH-patients. Additionally, as data on cortisol dynamics after SAH are scarce, diurnal cortisol profiles are investigated in patients in the acute and chronic phase, as well as the cortisol awakening response and feedback sensitivity in the chronic phase after SAH. As a result, it can be shown that some SAH patients exhibit lower serum cortisol levels but at the same time a higher cortisol awakening response in saliva than healthy controls. Also, patients in the chronic phase after SAH do have a stable diurnal cortisol rhythm while there are disturbances in around 50% of all patients in the acute phase, leading to the conclusion that a single baseline measurement of cortisol is of no substantial use for diagnosing cortisol dysregulations in the acute phase after SAH. It is assumed that in SAH patients endocrine changes occur over time and that a combination of adrenal exhaustion and a subsequent downregulation of corticosteroid binding globulin may be the most probable causes for the dissociation of serum cortisol concentrations and salivary cortisol profiles in the investigated SAH patients. These changes may be an emergency response after SAH and, as elevated free cortisol levels are connected to a better psychosocial outcome in patients in the chronic phase after SAH, this reaction may even be adaptive.
Background: We evaluated depression and social isolation assessed at time of waitlisting as predictors of survival in heart transplant (HTx) recipients. Methods and Results: Between 2005 and 2006, 318 adult HTx candidates were enrolled in the Waiting for a New Heart Study, and 164 received transplantation. Patients were followed until February 2013. Psychosocial characteristics were assessed by questionnaires. Eurotransplant provided medical data at waitlisting, transplantation dates, and donor characteristics; hospitals reported medical data at HTx and date of death after HTx. During a median followâ€up of 70 months (<1"93 months postâ€HTx), 56 (38%) of 148 transplanted patients with complete data died. Depression scores were unrelated to social isolation, and neither correlated with disease severity. Higher depression scores increased the risk of dying (hazard ratio=1.07, 95% confidence interval, 1.01, 1.15, P=0.032), which was moderated by social isolation scores (significant interaction term; hazard ratio = 0.985, 95% confidence interval, 0.973, 0.998; P=0.022). These findings were maintained in multivariate models controlling for covariates (P values 0.020"0.039). Actuarial 1â€year/5â€year survival was best for patients with low depression who were not socially isolated at waitlisting (86% after 1 year, 79% after 5 years). Survival of those who were either depressed, or socially isolated or both, was lower, especially 5 years posttransplant (56%, 60%, and 62%, respectively). Conclusions: Low depression in conjunction with social integration at time of waitlisting is related to enhanced chances for survival after HTx. Both factors should be considered for inclusion in standardized assessments and interventions for HTx candidates. We evaluated depression and social isolation assessed at time of waitlisting as predictors of survival in heart transplant (HTx) recipients.\r\n\r\nMethods and Results: Between 2005 and 2006, 318 adult HTx candidates were enrolled in the Waiting for a New Heart Study, and 164 received transplantation. Patients were followed until February 2013. Psychosocial characteristics were assessed by questionnaires. Eurotransplant provided medical data at waitlisting, transplantation dates, and donor characteristics; hospitals reported medical data at HTx and date of death after HTx. During a median followâ€up of 70 months (<1"93 months postâ€HTx), 56 (38%) of 148 transplanted patients with complete data died. Depression scores were unrelated to social isolation, and neither correlated with disease severity. Higher depression scores increased the risk of dying (hazard ratio=1.07, 95% confidence interval, 1.01, 1.15, P=0.032), which was moderated by social isolation scores (significant interaction term; hazard ratio = 0.985, 95% confidence interval, 0.973, 0.998; P=0.022). These findings were maintained in multivariate models controlling for covariates (P values 0.020"0.039). Actuarial 1â€year/5â€year survival was best for patients with low depression who were not socially isolated at waitlisting (86% after 1 year, 79% after 5 years). Survival of those who were either depressed, or socially isolated or both, was lower, especially 5 years posttransplant (56%, 60%, and 62%, respectively).
Numerous RCTs demonstrate that cognitive behavioral therapy (CBT) for depression is effective. However, these findings are not necessarily representative of CBT under routine care conditions. Routine care studies are not usually subjected to comparable standardizations, e.g. often therapists may not follow treatment manuals and patients are less homogeneous with regard to their diagnoses and sociodemographic variables. Results on the transferability of findings from clinical trials to routine care are sparse and point in different directions. As RCT samples are selective due to a stringent application of inclusion/exclusion criteria, comparisons between routine care and clinical trials must be based on a consistent analytic strategy. The present work demonstrates the merits of propensity score matching (PSM), which offers solutions to reduce bias by balancing two samples based on a range of pretreatment differences. The objective of this dissertation is the investigation of the transferability of findings from RCTs to routine care settings.
Internet interventions have gained popularity and the idea is to use them to increase the availability of psychological treatment. Research suggests that internet interventions are effective for a number of psychological disorders with effect sizes comparable to those found in face-to-face treatment. However, when provided as an add-on to treatment as usual, internet interventions do not seem to provide additional benefit. Furthermore, adherence and dropout rates vary greatly between studies, limiting the generalizability of the findings. This underlines the need to further investigate differences between internet interventions, participating patients, and their usage of interventions. A stronger focus on the processes of change seems necessary to better understand the varying findings regarding outcome, adherence and dropout in internet interventions. Thus, the aim of this dissertation was to investigate change processes in internet interventions and the factors that impact treatment response. This could help to identify important variables that should be considered in research on internet interventions as well as in clinical settings that make use of internet interventions.
Study I (Chapter 5) investigated early change patterns in participants of an internet intervention targeting depression. Data from 409 participants were analyzed using Growth Mixture Modeling. Specifically a piecewise model was applied to model change from screening to registration (pretreatment) and early change (registration to week four of treatment). Three early change patterns were identified; two were characterized by improvement and one by deterioration. The patterns were predictive of treatment outcome. The results therefore indicated that early change should be closely monitored in internet interventions, as early change may be an important indicator of treatment outcome.
Study II (Chapter 6) picked up on the idea of analyzing change patterns in internet interventions and extended it by using the Muthen-Roy model to identify change-dropout patterns. A sligthly bigger sample of the dataset from Study I was analyzed (N = 483). Four change-dropout patterns emerged; high risk of dropout was associated with rapid improvement and deterioration. These findings indicate that clinicians should consider how dropout may depend on patient characteristics as well as symptom change, as dropout is associated with both deterioration and a good enough dosage of treatment.
Study III (Chapter 7) compared adherence and outcome in different participant groups and investigated the impact of adherence to treatment components on treatment outcome in an internet intervention targeting anxiety symptoms. 50 outpatient participants waiting for face- to-face treatment and 37 self-referred participants were compared regarding adherence to treatment components and outcome. In addition, outpatient participants were compared to a matched sample of outpatients, who had no access to the internet intervention during the waiting period. Adherence to treatment components was investigated as a predictor of treatment outcome. Results suggested that especially adherence may vary depending on participant group. Also using specific measures of adherence such as adherence to treatment components may be crucial to detect change mechanisms in internet interventions. Fostering adherence to treatment components in participants may increase the effectiveness of internet interventions.
Results of the three studies are discussed and general conclusions are drawn.
Implications for future research as well as their utility for clinical practice and decision- making are presented.