@phdthesis{Zetzl2021,
  author    = {Zetzl, Teresa Margarete},
  title     = {Cancer-related fatigue intervention},
  doi       = {10.25972/OPUS-25166},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-251662},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {The incidence of cancer cases is rising steadily, while improved early detection and new cancer-specific therapies are reducing the mortality rate. In addition to curing cancer or prolonging life, increasing the quality of life is thus an important goal of oncology, which is why the burdens of cancer and treatment are becoming more important. A common side effect of cancer and its therapy is cancer-related fatigue, a tiredness that manifests itself on physical, emotional and cognitive levels and is not in proportion to previous physical efforts. Since the etiology of fatigue has not yet been fully clarified, symptom-oriented therapy is preferable to cause-specific therapy. In addition to activity management, sleep hygiene, and cognitive behavioral therapy, mind-body interventions such as yoga are recommended for reducing fatigue. Previous studies with small sample sizes were able to examine the efficacy of yoga regarding fatigue predominantly in patients with breast cancer. Long-term effects of yoga have rarely been studied and there have been no attempts to increase long-term effects through interventions such as reminder e-mails. This dissertation takes a closer look at these mentioned aspects of the study sample and long-term effects. An 8-week randomized controlled yoga intervention was conducted, including patients with different cancer types reporting mild to severe fatigue. Following the 8-week yoga therapy, a randomized group of participants received weekly reminder e-mails for 6 months for regular yoga practice, whereas the control group did not receive reminder e-mails. The first paper is a protocol article, which addresses the design and planned implementation of the research project this dissertation is based upon. This serves to ensure better replicability and comparability with other yoga studies. Due to a very low consent rate of patients in the pilot phase, it was necessary to deviate from the protocol article in the actual implementation and the planned inclusion criterion of fatigue >5 was reduced to fatigue >1. The second paper examines the efficacy of the eight-week yoga intervention. Patients in the intervention group who participated in the yoga classes seven times or more showed a significantly greater reduction in general and physical fatigue than those who participated less often. The efficacy of yoga was related to the number of attended yoga sessions. Women with breast cancer who participated in yoga reported greater reductions in fatigue than women with other cancer types. There was also an improvement for depression and quality of life after eight weeks of yoga therapy compared to no yoga therapy. These results imply that yoga is helpful in reducing depression and cancer-related fatigue, especially in terms of physical aspects and improving quality of life. The third paper focuses on the efficacy of reminder e-mails in terms of fatigue and practice frequency. Patients who received reminder e-mails reported greater reductions in general and emotional fatigue, as well as significant increases in practice frequency, compared to patients who did not receive reminder e-mails. Compared to fatigue scores before yoga, significantly lower fatigue and depression scores and higher quality of life were reported after yoga therapy and at follow-up six months later. Weekly e-mail reminders after yoga therapy may have positive effects on general and emotional fatigue and help cancer patients with fatigue establish a regular yoga practice at home. However, higher practice frequency did not lead to higher improvement in physical fatigue as found in Paper 2. This may indicate other factors that influence the efficacy of yoga practice on physical fatigue, such as mindfulness or side effects of therapy. This research project provides insight into the efficacy of yoga therapy for oncology patients with fatigue. It is important that such interventions be offered early, while fatigue symptoms are not too severe. Regular guided yoga practice can reduce physical fatigue, but subsequent yoga practice at home does not further reduce physical fatigue. Reminder emails after completed yoga therapy could only reduce patients' emotional fatigue. It may be that physical fatigue was reduced as much as possible by the previous yoga therapy and that there was a floor effect, or it may be that reminder emails are not suitable as an intervention to reduce physical fatigue at all. Further research is needed to examine the mechanisms of the different interventions in more detail and to find appropriate interventions that reduce all levels of fatigue equally.},
  subject      = {Erm{\"u}dungssyndrom},
  language  = {en}
}
@phdthesis{Glueck2024,
  author    = {Gl{\"u}ck, Valentina},
  title     = {Habitual avoidance in trait anxiety and anxiety disorders},
  doi       = {10.25972/OPUS-36022},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-360227},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Maladaptive avoidance behaviors can contribute to the maintenance of fear, anxiety, and anxiety disorders. It has been proposed that, throughout anxiety disorder progression, extensively repeated avoidance may become a habit (i.e., habitual avoidance) instead of being controlled by internal threat-related goals (i.e., goal-directed avoidance). However, the process of the acquisition of habitual avoidance in anxiety disorders is not yet well understood. Accordingly, the current thesis aimed to investigate experimentally whether trait anxiety and anxiety disorders are associated with an increased shift from goal-directed to habitual avoidance. The aim of Study 1 was to develop an experimental operationalization of maladaptive habitual avoidance. To this end, we adapted a commonly used action control task, the outcome devaluation paradigm. In this task, habitual avoidance was operationalized as persistent responses after extensive training to avoid an unpleasant stimulus when the aversive outcome was devalued, i.e., when individuals knew the aversive outcome could not occur anymore. We included indicators for costly and low-cost habitual avoidance, whereby habitual avoidance was associated with a monetary cost, while low-cost habitual avoidance was not associated with monetary costs. In Experiment 1 of Study 1, a pronounced costly and non-costly outcome devaluation effect was observed. However, this result may have partly resulted from trial-and-error learning or a better-safe-than-sorry strategy since not instructions about the stimulus-response-outcome contingencies after the outcome devaluation procedure had been provided to the participants. In Experiment 2 of Study 1, instructions on these stimulus-response-outcome contingencies were included to prevent the potential confounders. As a result, we observed no indicators for costly habitual avoidance, but evidence for low-cost habitual avoidance, potentially because competing goal-directed responses could easily be implemented and inhibited costly habitual avoidance tendencies. In Study 2, the strength of habitual avoidance acquisition was compared between participants with and without anxiety disorders, using the experimental task of Experiment 1 in Study 1. The results indicated that costly and low-cost habitual avoidance was not more pronounced in participants with anxiety disorders than in the healthy control group. However, in an exploratory subgroup comparison, panic disorder predicted more substantial habitual avoidance acquisition than social anxiety disorder. In Study 3, we investigated whether trait anxiety as a risk factor for anxiety disorders is associated with a specific increased shift from goal-directed to habitual avoidance and approach. The task from the Experiment 1 of Study 1 was adapted to include parallel versions for operationalizing habitual avoidance and habitual approach responses. Using a within-subjects design, the individuals - pre-screened for high and low trait anxiety - took part in the approach and the avoidance outcome devaluation task version. The results suggested stronger non-costly habitual responses in more highly trait-anxious individuals independent of the task version, and suggested a tendency towards an impact of trait anxiety on costly habitual approach rather than on costly habitual avoidance. In summary, individuals with high trait anxiety or anxiety disorders did not develop habitual avoidance more readily than individuals with low trait anxiety or without anxiety disorders. Therefore, this thesis does not support the assumption that an increased tendency to acquire habitual avoidance contributes to persistent maladaptive avoidance in anxiety disorders. The thesis also contributes to the discourse on the validity of outcome devaluation studies in general by highlighting the impact of task features, such as the instructions after the outcome devaluation procedure or the task difficulty in the test phase, on the experimental results. Such validity issues may partly explain the heterogeneity of findings in research with the outcome devaluation paradigm. We suggest ways towards more valid operationalizations of habitual avoidance in future studies.},
  subject      = {Gewohnheit},
  language  = {en}
}