Roland Mergl - Academia.edu (original) (raw)

Papers by Roland Mergl

Maintaining temporal coordination across physiological systems is crucial at the wake-sleep trans... more Maintaining temporal coordination across physiological systems is crucial at the wake-sleep transition. As shown in recent studies, the degree of coordination between brain and autonomic arousal influences attention, which highlights a previously unrecognised point of potential failure in the attention system. To investigate how cortical and autonomic dynamics are linked to the attentive process we analysed electroencephalogram, electrocardiogram and skin conductance data of 39 healthy adults recorded during a 2-h resting-state oddball experiment. We related cross-correlations to fluctuation periods of cortical and autonomic signals and correlated obtained measures to event-related potentials N1 and P2, reflecting excitatory and inhibitory processes. Increasing alignment of cortical and autonomic signals and longer periods of vigilance fluctuations corresponded to a larger and earlier P2; no such relations were found for N1. We compared two groups, with (I) and without measurable (II) delay in cortico-autonomic correlations. Individuals in Group II had more stable vigilance fluctuations, larger and earlier P2 and fell asleep more frequently than individuals in Group I. Our results support the hypothesis of a link between cortico-autonomic coupling and dynamics and central inhibition. Quantifying this link could help refine classification in psychiatric disorders with attention and sleep-related symptoms, particularly in ADHD, depression, and insomnia. One of the main functions of the human brain is the co-regulation of cortical and autonomic arousal in adaptation to environmental and homeostatic requirements. In the process of falling asleep, cortical and autonomic arousal levels are gradually downregulated 1 , shielding the brain from irrelevant stimuli and promoting sleep onset 2,3. Conversely, nocturnal awakenings, due to loud noise for example, are marked by sudden heart rate responses and changes in mental and attentional states. Thus, temporal coordination of different physiological modalities is crucial at state transitions 4 , but research on how theses subsystems communicate and to what extent their interplay influences attentional processes is still in an early stage. While the dynamics of autonomic arousal levels can be tracked by observing the heart rate and skin con-ductance, levels of brain arousal as well as attentional processes can be observed in electroencephalographic recordings (EEG). The time course of brain arousal is reflected in spontaneous changes in the EEG, which we can automatically classify as 1-s EEG-vigilance stages 5–8. Components of event-related potentials (ERP) visible in the EEG in response to sensory (e.g., auditory) stimuli reflect different functional processes. We discuss a negative component N1, centered around 100 ms after the stimulus onset 9 and the following positive component P2 10. Chait et al. 11 as well as others 12–14 observed enhanced P2 amplitude in response to actively ignored tones during a selective attention task. In such paradigms of selective attention or discrimination, P2 reflects inhibitory processes 11,13 possibly modulating thresholds of conscious perception by suppressing interference from distracting stimuli 11,12 , thereby facilitating stimuli discrimination 15,16 resulting in improved reaction times 15. The component N1 is often considered a mostly exogenous component (related to stimulus properties), associated with the Published: xx xx xxxx OPEN

Background. Th e " Onset of Depression Inventory " (ODI) represents a patient interview which aim... more Background. Th e " Onset of Depression Inventory " (ODI) represents a patient interview which aims to register the speed of onset of depression systematically. Th e purpose of this study was to evaluate the patient-relative agreement regarding the speed of onset of depression in the patients. Methods. Th e ODI was investigated in 31 patients with a depressive episode. Moreover, 31 patients ' relatives participated in an interview for which a modifi ed version of the ODI (for relatives of depressed patients; ODI-A) was applied. Results. Th ere was a signifi cant association between patients ' estimation of the speed of onset of the depressive episode and relatives ' estimation of this parameter in the case of patients and relatives living in a common household (rho ϭ 0.68; p ϭ 0.006). Conclusions. Th ere was an agreement between patients and their relatives regarding the speed of onset of the current depressive episodes, however only if they lived in a common household.

Context Chronic systemic inflammation in obesity originates from local immune responses in viscer... more Context Chronic systemic inflammation in obesity originates from local immune responses in viscer-al adipose tissue. However, assessment of a broad range of inflammation-mediating cyto-kines and their relationship to physical activity and adipometrics has scarcely been reported to date. Objective To characterize the profile of a broad range of pro-and anti-inflammatory cytokines and the impact of physical activity and energy expenditure in individuals with general obesity, central obesity, and non-obese subjects. A cross-sectional study comprising 117 obese patients (body mass index (BMI) ! 30) and 83 non-obese community-based volunteers. Main Outcomes Measures Serum levels of interleukin (IL)-2, IL-4, IL-5, IL-10, IL-12, IL-13, granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon (IFN)-γ and tumor necrosis factor (TNF)-α were measured. Physical activity and energy expenditure (MET) were assessed with acti-graphy. Adipometrics comprised BMI, weight, abdominal-, waist-and hip-circumference, waist to hip ratio (WHR), and waist-to-height-ratio (WHtR).

istic study. Conclusions: While the speed of onset of depres-sive episodes has been found to show... more istic study. Conclusions: While the speed of onset of depres-sive episodes has been found to show large interindividual variability and some intraindividual stability, the data of this study do not indicate that the neurobiological processes involved in the onset of and in the recovery from depressive episodes are closely linked.

Background: It has yet to be established whether gender moderates or predicts outcome of psycholo... more Background: It has yet to be established whether gender moderates or predicts outcome of psychological and pharmacological treatments for adult depression because: (1) individual randomized trials typically lack sufficient statistical power to detect moderators and predictors and (2) meta-analyses cannot examine such associations directly. Methods: We conducted an " individual patient data "

Both depression and chronic obstructive pulmonary disease (COPD) are prevalent, severe and often ... more Both depression and chronic obstructive pulmonary disease (COPD) are prevalent, severe and often comorbid disorders. There is a risk of undertreatment for depression in patients with COPD as depressive symptoms, including suicidal tendencies, can erroneously be conceptualised as an understandable reaction to COPD and not as signs of an independent depressive disorder. In this context, the comorbidity rates of COPD and depression, the risk of suicidal behaviour in patients with COPD, and the evidence base for pharmaco-and psychotherapy in these patients are reviewed. Because symptoms of depression and COPD overlap it remains unclear how far the prevalence of major depression in COPD exceeds that in the general population. The suicide risk appears to be increased in COPD. Methodological studies providing evidence for the antidepressant efficacy of antidepressants or psychotherapy in patients with COPD are lacking. Recommendations for clinicians on how to separate depression from an understandable reaction to COPD are provided. Given the profound effects of depression on quality of life, life expectancy, COPD prognosis and suicide risk it is important to carefully diagnose and treat depression in patients with COPD according to national guidelines. @ERSpublications Comorbid depression has profound effects on COPD prognosis and should not be seen as understandable reaction to COPD http://ow.ly/vNC9G For editorial comments see page 570. Conflict of interest: Disclosures can be found alongside the online version of this article at erj.ersjournals.com

In major depressive disorder, changes in cytokine levels have been reported to play a role in pat... more In major depressive disorder, changes in cytokine levels have been reported to play a role in patho-genesis. Therefore, we sought to investigate a broad range of cytokines in depression. We compared serum levels of interleukin (IL)-2, IL-4, IL-5, IL-10, IL-12, IL-13, granulocyte macrophage colony-stimulating factor (GM-CSF), interferon (INF-g) and tumor necrosis factor (TNF)-a in 64 subjects with current depression and 206 non-depressed subjects. Depressed patients had higher levels of IL-2, IL-5, IL-12, IL-13, GM-CSF, INF-g and TNF-a, compared to non-depressed subjects. Splitting groups into non-obese (BMI < 30) and obese (BMI ! 30), the non-obese depressed patients (n ¼ 40) showed elevated IL-5, IL-12, IL-13, GM-CSF, INF-g and TNF-a levels compared to non-obese and non-depressed subjects (n ¼ 85). The obese and depressed patients (n ¼ 24) showed elevated levels of IL-5, IL-12 and INF-g compared to obese but not depressed subjects (n ¼ 121). Levels of several cytokines were found to be associated with physical activity, employment status and presence of daily naps. The results support over-expression of pro-inflammatory cytokines in depression and extend the range of cytokines potentially associated with depression to include GM-CSF, IL-5 and IL-13. Changes in these cytokines may contribute to co-morbidity between depression and allergic and asthmatic diseases. The results also suggest inflammatory processes associated with obesity, and support an interaction between cytokine serum concentrations and behavioral aspects of both obesity and depression.

Background: The neuropeptide S receptor (NPSR1) and its ligand neuropeptide S (NPS) have received... more Background: The neuropeptide S receptor (NPSR1) and its ligand neuropeptide S (NPS) have received increased attention in the last few years, as both establish a previously unknown system of neuromodulation. Animal research studies have suggested that NPS may be involved in arousal/wakefulness and may also have a crucial role in sleep regulation. The single nucleotide polymorphism (SNP) rs324981 in NPSR1 has begun to shed light on a function of the NPS-system in human sleep regulation. Due to an amino acid exchange, the T-allele leads to an increased sensitivity of the NPSR1. In the only genome-wide association study to date on circadian sleep parameters in humans, an association was found between rs324981 and regular bedtime. However, the sleep parameters in this study were only measured by self-rating. Therefore, our study aimed to replicate these findings using an objective measure of sleep.

verity. Conclusions: The ODI allows reliable assessment of the speed of onset of depressive episo... more verity. Conclusions: The ODI allows reliable assessment of the speed of onset of depressive episodes. The instrument might be useful for the detection of hidden bipolarity.

Background: After the railway suicide of the German national goalkeeper Robert Enke in 2009, a si... more Background: After the railway suicide of the German national goalkeeper Robert Enke in 2009, a significant increase of railway suicides was observed nationally. This study analyses whether this incident also triggered copycat effects in other European countries. Additionally, media coverage proxied by Google Trends and long-term changes taking into account general changes in suicide rates and kilometres driven by trains were examined. Methods: The numbers of railway suicides before and after Enke´s suicide were analysed for short and long-term periods (2 weeks and 2 years post-event) across five European countries. Incidence ratios and resulting percentage changes were computed. Results: Similar to Germany, there were significant short and long-term effects for the combined data of the four other countries (increase of 93.9%; p¼ 0.004 and 16.7%; p¼ 0.003). There was no indication that long-term effects are a mere reflection of an overall increase in suicide frequencies or due to increased numbers of kilometres driven by trains. Analyses on country level revealed heterogeneous results. Limitations: Due to incomplete data, analyses regarding age and gender were not performed. Media coverage was only proxied by a Google Trends analysis. The study includes a small sample of European countries. Conclusions: Enke's suicide in 2009 was followed by increasing train suicide numbers in Europe. Although this incident may have reinforced an existing European trend of growing railway suicides, an international copycat effect and/or an increased overall awareness about this particular suicide method appears to be one likely explanation for the changes.

Neuropsychiatrie, 2009

Erkrankte und Angehörige -eine Untersuchung zu Motiven und Auswirkungen der Teilnahme Anliegen: E... more Erkrankte und Angehörige -eine Untersuchung zu Motiven und Auswirkungen der Teilnahme Anliegen: Es wird untersucht, welche psychiatrischen Diagnosen bei den Schreibern eines Online-Diskussionsforums vorherrschend sind und ob das Forum als Alternative oder Ergänzung zu professioneller Behandlung genutzt wird. Des Weiteren wird dargestellt, wie sich die Teilnahme im Forum auf den individuellen Umgang mit der Krankheit Depression auswirkt. Methode: 55 aktive Nutzer wurden mit Hilfe der computerunterstützten Fassung eines vollstrukturierten psychiatrischen Interviews (DIA-X) telefonisch be-fragt. Der Behandlungsstatus und die Motive zur Nutzung des Forums wurden online erhoben. Ergebnisse: 52 Studienteilnehmer (94,5%) erhielten die Lebenszeitdiagnose Depression. 90,2% sind schon einmal wegen Depressionen ambulant psychiatrisch behandelt worden, 64,7% waren stationär aufgenommen. Die Befragten gaben an, dass durch ihre Teilnahme am Forum das Vertrauen in die medizinische Behandlung gestiegen ist (63,3%) und sie dazu ermutigt worden sind, sich in ärztliche bzw. therapeutische Behandlung zu begeben (61,2%). 32,7% der befragten Forumsteilnehmer schätzten ihre Einstellung gegenüber einer Behandlung mit Medikamenten positiver ein als noch vor der Kontaktaufnahme mit dem Forum. Schlussfolgerungen: Das Forum erreicht seine Zielgruppe und wird nicht als Alternative, sondern als Ergänzung zu professioneller ärztlicher und psychologischer Betreuung genutzt. Aspekte der Selbsthilfe, insbesondere eine Stärkung des Gemeinschaftsgefühls und die Akzeptanz und Bewältigung der eigenen krankheitsbedingten Situation können durch die Teilnahme am Online-Diskussionsforum erreicht werden. Internetforen können eine sinnvolle Rolle im Gesamtbehandlungskonzept spielen.

Neuropsychiatrie, 2009