1) Mechanisms of Stress
- Air Pollution and Stress Resilience in a representative Study of Germany
Recently, there has been a growing debate on the role of the physical environment and mental health. The relevance of gaining more insights on what constitute risk and protective factors for mental health seems to be more important now than ever. This study investigates the physical environmental factor air pollution measured by particulate matter of particles with an aerodynamic diameter smaller than 10 µm (PM10) with and effects on mental health and well-being factors (life satisfaction, stress resilience, anxiety, depression, and self-esteem). A nationally representative face- to-face household survey was conducted. The representative German sample with an age range between 18 to 92 years is used. Addresses were selected according to the random route procedure. Of the 8,398 addresses selected, 8,106 proved valid. A total of 5,036 persons agreed to participate, provided verbal in- formed consent, and completed the study questionnaires. The response rate among those individuals who were asked to participate by the interviewers was 72.9%. Considering that Germany is still not reaching the WHO air quality standards - poor air quality may affect a large proportion of Germans.
2) Therapy & Outcome
- Exploring Relaxation and Stress Immunization in virtual Environments (VR)
Virtual reality (VR) environments and head-mounted devices (HMD) for immersive experiences are not new. However, the technological progress with HMDs for a broader target group has developed rapidly within a short period of time. Strong competition between providers leads to reduced prices on the markets, improves the quality of devices with high definition (HD) resolutions, and a more suitable comfort for everyday usage. Many applications from various providers are entering the markets and App-Stores; some promise health benefits without having scientifically proven evidence. So far, research mainly examined patient populations applying virtual reality exposure therapy (VRET). In particular for specific phobias, panic disorders, or post-traumatic stress disorders (PTSD). However, there is not much empirical psychophysiological data available on healthy individuals using HMDs for virtual environments, the possible adaption process of repeated application, neurological impacts of this immersive stimulus (visual/audio), or health promoting effects of VR interventions. Thus, the aim is to investigate effects of standardized repeated VR exposure on stress reactivity and relaxation in healthy adults to promote effective stress resilience training.
- Effects of heart rate variability (HRV) biofeedback on HRV and immune response in patients with panic disorder
The aim of the present study is to analyze the effects of HRV biofeedback on HRV, symptom severity and cytokine concentration in patients diagnosed with panic disorder (PD). Patients with anxiety disorders, especially PD patients, exhibit reduced HRV indices. First results suggest an association between PD and elevated levels of pro-inflammatory cytokines. Prior studies showed that HRV biofeedback is effective in reducing symptoms of mental disorders associated with autonomic dysbalance. It has not been explored yet to what extent HRV biofeedback alone could be an effective treatment since most studies implemented HRV biofeedback in addition to treatment as usual. Further it is unknown if HRV biofeedback is capable of modulating cytokine production. At follow-up six weeks after the last training sessions, HRV, symptom severity and cytokine concentration will be analyzed again. This study tests for the first time (1) if HRV biofeedback will be effective in the treatment of PD, and (2) if HRV biofeedback will positively modulate cytokine production.
- Exposure therapy for patients with agoraphobia with an innovative 360° real life virtual reality-technique
Agoraphobia with or without panic disorder (PD) is an anxiety disorder characterized by avoiding certain places, such as public transportation or bridges. Due to the high stress on those affected, it is one of the most common diagnoses in outpatient psychotherapy. Cognitive behavioral therapy (CBT) with exposure in vivo is considered to be the “gold standard” of psychotherapeutic treatment because of its consistently high therapeutic effects. However, studies show that 90% of agoraphobic patients receive psychotropic drugs and only 8% receive exposure therapy. Instead, therapists primarily conduct interoceptive or in sensu exposure. Obstacles in the implementation of in vivo exposures, such as large expenditure of time and money, could be overcome with exposure therapy in virtual reality (VRET). VRET has been shown to be effective for specific phobias and social phobia. Some studies also show a reduction in subjectively reported symptoms and arousal in patients with PD and agoraphobia. The main problems of these studies are the assessment of predominantly subjective symptoms, whereby psychophysiological measures were mostly neglected, the results were rarely replicated, only small sample sizes were examined and no real images were used for the VR scenarios. The planned study examines the effectiveness of VRET in comparison to CBT without in vivo exposure in patients with agoraphobia with regard to subjective symptom burden. In addition, psychophysiological measures such as heart rate (HR), heart rate variability (HRV), pulse wave velocity (PWV), skin conductance (SC) and salivary cortisol are recorded during the exposure sessions.
- Comparison of the habituation processes between healthy people and patients with social phobia before and after exposure treatment
Social phobia is one of the most common anxiety disorders. It is proposed that dysfunctional strategies for coping with social phobic anxiety reduce the possibility of relearning and habituation. The most effective therapy is confrontation in vivo. Social phobic patients are confronted with anxiety-provoking situations to make experiences incongruent with their fears and in turn show a reduced physiological reaction. In this way, confrontation leads to a correction of social-phobic cognitions and to physiological habituation. For now, it is unclear why manualized confrontation therapy does not work for all social phobic patients. It is proposed that reasons may be security behavior and differences in the ability of habituation. It seems that the autonomic nervous system and the Hypothalamic-pituitary-adrenocortical (HPA) axis play an important role. Studies show that if a standardized combination of tasks like the TSST is used for stress induction with social phobic patients, they show a cortisol-hyperreactivity. This supports the idea of differences in habituation between healthy and social phobic persons. Based on the current literature it is unclear if this differences in stress-responsivity are related with differences in habituation and therapy success and if a change of social-phobic cognitions throughout therapy is related with changes in stress-responsivity.
3) Psychoneuroendocrinology of mental disorders
- Comparison of the chewing behaviour of patients suffering from obesity and healthy participants under resting and stress conditions
Obesity has a prevalence rate greater than 20 percent in Germany. It increases the rate of many health risks of the persons suffering from it. According to the selfish brain theory, reasons for it are (amongst others) faulty regulation processes of the energy balance in the brain. Main factors of these regulation processes are the hypothalamic-pituitary-adrenocortical-axis (HPA axis), the Corticotropin releasing factor (CRF) and Cortisol. However, stress induced concentrations of CRF and Cortisol vary depending on the individual. Hence, stress induced CRF and Cortisol increase food intake for some persons, while it is lowered for others. These differences are caused due to individual differences in Cortisol concentrations under stress conditions. It is yet unknown whether higher Cortisol concentrations under stress conditions cause higher rates of food intake and higher chewing frequency. Therefore, eating and chewin behaviour and the Cortisol concentrations under resting and stress conditions shall be investigated in this study. Psychosocial stress will be induced by the Trier Social Stress Test (TSST), a psychosocial stress test. To specify eating and chewing behaviour, a new, innovative recording device is uses, the chewing frequency sensor. Using it, we will be able to investigate if stress induced Cortisol concentrations could change the eating behaviour and the chewing frequency. This information might clarify ethiologic processes and be a basis for the prevention of health risks in patients suffering from eating disorders (e.g. Anorexia Nervosa, Bulimia Nervosa, obesity).
4) Vulnerability & Resilience
- Habituation or sinsitivation as a possible resilience mechanism and vulnerability mechanism
According to the TK Stress Study 2016, increasing stress is responsible for increasing sick days (> 15 sick days per person and year). Fatigue is cited as the second most common cause of chronic complaints. Everyone is exposed to stress in their everyday life. Some stressors occur repeatedly or even regularly (illnesses, conflicts in work or private life, etc.). In order to stay mentally and physically healthy, it is necessary to adapt to these stressors in such a way that they are not a regular burden. Some people manage this habituation to stressful events, whereas other people react more intensely to repeated confrontation (sensitization) and are thus at risk of developing stress-related illnesses. The question arises as to which factors have an influence on whether someone shows habituation or sensitization to a repeated stressor. In this study with within-subject design, examinations on the habituation or sensitization of the hormonal stress load to repeated stressors are examined on healthy test persons. The stress parameters are recorded before and after repeated physiological stressors (electrodermal stimulation).
- Cumulative hair cortisol before a traffic accident with traumatic brain injury as a predictor for the development and course of trauma-related disorders
Traumatic brain trauma (SHT) occurs in Germany with a frequency of 323 per 100,000 inhabitants annually. Studies have shown a connection between TBI and impaired attention and concentration, psychological symptoms (depressive mood, aggressiveness) as well as trauma-related disorders. It is known that post-trauma disorders are characterized by hypo- or hypercortisolism, which influence the immune parameters and the course of the disease. It is still unknown, however, whether the changed stress hormone level already existed before the trauma or whether it was caused by the traumatic event. The aim of the present study is to investigate whether the stress hormone cortisol in the hair serves as a predictor for the development of trauma-related disorders and a problematic course of the disease prior to a traffic accident with a traumatic brain injury. A sample of N = 192 patients with TBI after a traffic accident and N = 192 healthy control persons are to be examined. For this purpose, a hair segment sample is taken shortly after the traffic accident and after three and six months, and psychological symptoms, concentration and attention are checked. The results obtained from this study would be of great interest for the development of effective preventive measures.