Multimodal Assessment of Smoking cue Reactivity During a Smoking Cue Exposure Task

Background. Cue-reactivity as a characteristic symptom of substance use disorders (SUD) is highly context dependent. Paradigms with high context validity need to be established for the investigation of underlying neurobiological mechanisms. While craving can be assessed by self-report as one aspect of cue-reactivity (CR), the assessment of biological measures such as the autonomous response and EEG promises a holistic perspective including CR at an automatized level. In a multimodal approach, smoking cue exposure (CE) effects on heart rate variability (HRV), EEG frequency power, and craving as well as their interrelation were assessed. This pilot study focused on the validity of CR measurements in a naturalistic CE paradigm. Methods. EEG frequency power, HRV, and craving were assessed during resting state (RS) and smoking CE in smokers (n = 14) and nonsmoking controls (n = 10) to investigate the psychophysiological and subjective reactions to CE. Results. Increased beta power was found only in smokers during CE compared to the control condition. There was an inverse correlation of beta power and maximum craving. Likewise, HRV correlated negatively with maximum smoking urges in smokers immediately after the measurements, without differentiation between CE and control condition. Conclusion. The increased beta power in smokers during CE is discussed as increased inhibitory control related to reduced craving in smokers. Furthermore, increased craving during CE seems to be associated to decreased vagal activity. The multimodal measurements during the CE showed ecological validity to be fundamental for CE assessment in clinical populations to evaluate its predictive value.

[VR-supported therapy for anxiety and posttraumatic stress disorder: current possibilities and limitations]

BACKGROUND

Virtual reality (VR) is increasingly used in psychotherapy, and the speed of development of therapeutic VR tools is continuously increasing.

OBJECTIVE

This narrative review provides an overview of the state of the art regarding VR applications for psychotherapy.

MATERIAL AND METHODS

The current state of VR therapy research for anxiety disorders and posttraumatic stress disorder (PTSD) is summarized. The focus lies on VR exposure therapy. Current developments in the field are outlined.

RESULTS

For anxiety disorders, especially phobic disorders, there are already positive recommendations in the current German S3 guidelines. For PTSD, the development of VR therapy tools is still in a relatively early stage.

CONCLUSION

The development of mobile cost-effective VR solutions in recent years has enabled entirely new applications for VR. The empirical challenges of these new developments are considerable. Nevertheless, the chances for an improvement of psychotherapeutic routine care are good.

Driving-related cognitive skills during antidepressant transcranial direct current stimulation: results in a subsample from the DepressionDC trial

Therapeutic transcranial direct current stimulation (tDCS) is a well-tolerated neuromodulatory intervention. However, there are currently no data on its impact on driving skills. Therefore, we conducted a validated assessment of driving-related cognitive skills in participants of the DepressionDC trial, a multicenter, randomized-controlled trial investigating the antidepressant effects of 6-week prefrontal tDCS in patients with major depressive disorder (MDD). Twenty-one patients (12 women, active tDCS, n = 11, sham, n = 10) underwent an assessment of driving-related cognitive skills before and after the intervention. Using a Bayesian analysis approach, we found no group differences between active tDCS and sham tDCS in the pre-post treatment changes for visual perception (estimated median difference: 3.41 [-3.17, 10.55 89%-CI], BF01: 2.1), stress tolerance (estimated median difference: 0.77 [-2.40, 4.15 89%-CI], BF01: 1.6), and reaction time (estimated median difference: 2.06 [-12.33, 16.83 89%-CI], BF01: 6.5). Our results indicate that repeated sessions of a conventional bifrontal tDCS protocol do not negatively impact driving-related cognitive skills in patients with MDD.

Distraction versus focusing during VR exposure therapy for acrophobia: A randomized controlled trial

BACKGROUND AND OBJECTIVES

The therapeutic mechanisms of exposure therapy are not well understood. Research suggests that focusing on the most feared aspect might not be necessary, and that distraction with a low cognitive load (e.g., conversation) might enhance exposure. We aimed at systematically testing the efficacy of exposure therapy with focusing vs. conversational distraction, hypothesizing that distracted exposure would yield superior effects.

METHODS

Thirty-eight patients with acrophobia (specific phobia of heights; clinician-determined) (free from relevant somatic or other mental disorders) were randomly assigned (1:1) to one virtual reality (VR) session of either focused (n = 20) or distracted exposure (n = 18). This monocentric trial took place at a psychiatric university hospital.

RESULTS

Both conditions resulted in a significant reduction of acrophobic fear and avoidance, and a significant increase of self-efficacy (primary outcome variables). However, condition did not have a significant effect on any of these variables. Effects were stable at four-week follow-up. Heart rate and skin conductance level indicated significant arousal, but did not differ between conditions.

LIMITATIONS

Eye-tracking was unavailable, nor did we assess emotions other than fear. Power was limited due to sample size.

CONCLUSIONS

A balanced exposure protocol combining attention to fear cues with conversational distraction, while not being superior, might be as effective as focused exposure for acrophobia, at least during the initial stages of exposure therapy. These results support previous findings. This study demonstrates how VR can be exploited for therapy process research, as VR supports dismantling designs and the incorporation of online process measures.

Transcranial direct current stimulation as an additional treatment to selective serotonin reuptake inhibitors in adults with major depressive disorder in Germany (DepressionDC): a triple-blind, randomised, sham-controlled, multicentre trial

BACKGROUND

Transcranial direct current stimulation (tDCS) has been proposed as a feasible treatment for major depressive disorder (MDD). However, meta-analytic evidence is heterogenous and data from multicentre trials are scarce. We aimed to assess the efficacy of tDCS versus sham stimulation as an additional treatment to a stable dose of selective serotonin reuptake inhibitors (SSRIs) in adults with MDD.

METHODS

The DepressionDC trial was triple-blind, randomised, and sham-controlled and conducted at eight hospitals in Germany. Patients being treated at a participating hospital aged 18-65 years were eligible if they had a diagnosis of MDD, a score of at least 15 on the Hamilton Depression Rating Scale (21-item version), no response to at least one antidepressant trial in their current depressive episode, and treatment with an SSRI at a stable dose for at least 4 weeks before inclusion; the SSRI was continued at the same dose during stimulation. Patients were allocated (1:1) by fixed-blocked randomisation to receive either 30 min of 2 mA bifrontal tDCS every weekday for 4 weeks, then two tDCS sessions per week for 2 weeks, or sham stimulation at the same intervals. Randomisation was stratified by site and baseline Montgomery-Åsberg Depression Rating Scale (MADRS) score (ie, <31 or ≥31). Participants, raters, and operators were masked to treatment assignment. The primary outcome was change on the MADRS at week 6, analysed in the intention-to-treat population. Safety was assessed in all patients who received at least one treatment session. The trial was registered with ClinicalTrials.gov (NCT02530164).

FINDINGS

Between Jan 19, 2016, and June 15, 2020, 3601 individuals were assessed for eligibility. 160 patients were included and randomly assigned to receive either active tDCS (n=83) or sham tDCS (n=77). Six patients withdrew consent and four patients were found to have been wrongly included, so data from 150 patients were analysed (89 [59%] were female and 61 [41%] were male). No intergroup difference was found in mean improvement on the MADRS at week 6 between the active tDCS group (n=77; -8·2, SD 7·2) and the sham tDCS group (n=73; -8·0, 9·3; difference 0·3 [95% CI -2·4 to 2·9]). Significantly more participants had one or more mild adverse events in the active tDCS group (50 [60%] of 83) than in the sham tDCS group (33 [43%] of 77; p=0·028).

INTERPRETATION

Active tDCS was not superior to sham stimulation during a 6-week period. Our trial does not support the efficacy of tDCS as an additional treatment to SSRIs in adults with MDD.

FUNDING

German Federal Ministry of Education and Research.

Virtuelle Realität bei Angsterkrankungen – vom experimentellen Tool zur klinischen Praxis

Anxiety disorders are among the most frequent psychiatric disorders. According to national and international guidelines, psychopharmacological as well as psychotherapeutic approaches are recommended as first-choice treatments, depending on diagnosis and severity. Among psychotherapeutic approaches, cognitive-behavioral therapy (CBT) has been investigated most. Here, exposure is of special relevance as the core element of treatment. The technology of virtual reality (VR) has been increasingly investigated as a possible add-on strategy or alternative to conventional exposure therapy. Numerous studies of VR exposure for anxiety disorders have been published. Further, the comparison of exposure treatment in vivo vs. in VR has been investigated in meta-analyses. The results are promising overall, however they do not yet justify a general recommendation of this treatment. There is still the need for more research, especially regarding treatment efficacy in large-scale studies with larger patient samples.

Effects of physical activity on cognitive performance: a controlled clinical study in depressive patients

Physical activity is a common adjunctive therapy in psychiatric and psychosomatic hospitals. In the present study, we assessed the effects of an exercise program, integrated into routine inpatient treatment, on cognitive performance and subjective severity of depression in a sample of patients suffering from major depression. We randomized n = 38 patients with unipolar depression to either physical exercise (n = 18) or occupational therapy as an active control treatment (n = 20). Both treatments were delivered in group format over a period of 3-4 weeks. Data indicate that there were significant improvements of cognitive functions and depressive symptoms in both groups, with specific treatment effects in reaction time and in short-term verbal memory favoring the physical activity group. In conclusion, we found physical exercise to be a feasible, easy-to-implement add-on therapy for depressive patients with promising effects on cognitive performance. However, these results need to be replicated in larger samples with an extended follow-up.

Das Potenzial der virtuellen Realität in der Verhaltenstherapie

Gegenstand und Ziel: Seit gut 20 Jahren wird virtuelle Realität (VR) als neue Methode in der kognitiven Verhaltenstherapie (KVT) erforscht. Das Potenzial von VR in der KVT soll anhand eines aktuellen Überblicks dargestellt werden.

Methoden: Der vorliegende Beitrag ist eine Übersichtsarbeit, in der der mögliche Nutzen von VR in der KVT sowie die aktuellen Entwicklungen und Herausforderungen in diesem Bereich herausgearbeitet werden.

Ergebnisse: Der Einsatz von VR könnte den Aufwand einiger KVT-Interventionen senken und ihre Verfügbarkeit erhöhen. Darüber hinaus kann VR in der Psychotherapieforschung die Entwicklung der KVT vorantreiben. VR-Expositionstherapie bei Angststörungen ist die am besten untersuchte VR-Anwendung in der KVT, zahlreiche weitere Ansätze stehen am Beginn der Entwicklung und Evaluation.

Schlussfolgerung(en): Nach wie vor besteht enormer Forschungsbedarf, um den möglichen Mehrwert von VR-Interventionen kritisch und multidimensional zu bestimmen.

Klinische Relevanz: VR-Interventionen sind kaum im klinischen Alltag angekommen, scheinen jedoch eine zunehmend wichtige Rolle in Forschung und Praxis der KVT zu spielen.

[Evaluation of a neuropsychological test battery with psychiatric and psychosomatic patients]

Neuropsychological assessment should be an integral component of clinical psychiatric diagnostics. Yet, the commonly used tests have not been investigated adequately for this population so far. The current study evaluated a clinically approved neuropsychological test battery by analyzing data on 226 mentally ill patients using factor and regression analyses. The extraction of three factors (Speed, Memory, and Executive Functions) proved to be adequate as the tests could be allocated properly. Regression analysis revealed an economical basis assessment consisting of three tests (TAP Alertness, VLMT, and Matrices Test). Based on acceptance, economy, and factorial structure aspects, we recommend the investigated test battery for neuropsychological assessment of psychiatric and psychosomatic patients.

Is prepulse modification altered by continuous theta burst stimulation? DAT1 genotype and motor threshold interact on prepulse modification following brain stimulation

Previous studies suggest an inhibitory top-down control of the amygdala by the prefrontal cortex (PFC). Both brain regions play a role in the modulation of prepulse modification (PPM) of the acoustic startle response by a pre-stimulus. Repetitive transcranial magnetic stimulation (rTMS) can modulate the activity of the PFC and might thus affect PPM. This study tested the effect of inhibitory rTMS on PPM accounting for a genetic variant of the dopamine transporter gene (DAT1). Healthy participants (N = 102) were stimulated with continuous theta burst stimulation (cTBS, an intense form of inhibitory rTMS) or sham treatment over the right PFC. Afterwards, during continuous presentation of a background white noise a louder noise burst was presented either alone (control startle) or preceded by a prepulse. Participants were genotyped for a DAT1 variable number tandem repeat (VNTR) polymorphism. Two succeeding sessions of cTBS over the right PFC (2 × 600 stimuli with a time lag of 15 min) attenuated averaged prepulse inhibition (PPI) in participants with a high resting motor threshold. An attenuation of PPI induced by prepulses with great distances to the pulse (480, 2000 ms) was observed following active cTBS in participants that were homozygous carriers of the 10-repeat-allele of the DAT1 genotype and had a high resting motor threshold. Our results confirm the importance of the prefrontal cortex for the modulation of PPM. The effects were observed in participants with a high resting motor threshold only, probably because they received a higher dose of cTBS. The effects in homozygous carriers of the DAT1 10-repeat allele confirm the relevance of dopamine for PPM. Conducting an exploratory study we decided against the use of a correction for multiple testing.

Soziales Kompetenztraining in Virtueller Realität bei sozialer Angst

Zusammenfassung. Theoretischer Hintergrund: Soziale Kompetenztrainings sind wichtige Werkzeuge bei der Psychotherapie der Sozialen Angststörung. Die Durchführung in Virtueller Realität (VR) könnte die Verfügbarkeit und Effektivität erhöhen, allerdings besteht ein Bedarf an validierten VR-Szenarien. Fragestellung: Geprüft wird die Validität von zwei in Anlehnung an das Gruppentraining sozialer Kompetenzen von Hinsch und Pfingsten (2015) entwickelten VR-Szenarien. Es wird angenommen, dass die durch das Szenario ausgelösten Komponenten sozialer Angst auf subjektiver, psychophysiologischer und kognitiver Ebene signifikant zwischen höher (HSA) und niedriger (NSA) sozial ängstlichen Personen differenzieren. Methode: Insgesamt durchliefen N = 55 HSA und NSA Studierende zwei VR-Szenarien vom Typ „Recht durchsetzen“. Zusätzlich wurde experimentell die Blickkontaktdauer des virtuellen Gesprächspartners variiert. Hauptoutcome war die erlebte Angst in den Rollenspielen. Zusätzlich wurden Herzschlagfrequenz, Hautleitfähigkeit sowie die Einschätzung der eigenen Kompetenz erfasst. Ergebnisse: HSA im Vergleich zu NSA berichteten für beide Szenarien signifikant höhere Angst sowie negative Verzerrungen in Bezug auf die Einschätzung der eigenen Kompetenz. Zusätzlich zeigte sich eine physiologische Aktivierung während der Rollenspiele, aber keine Differenzierung zwischen beiden Gruppen. Beide VR-Szenarien wurden als realistisch empfunden. Schlussfolgerungen: Virtuelle Interaktionsszenarien können zu Trainingszwecken genutzt werden und Soziale Kompetenztrainings in VR haben ein großes Potential für den Einsatz als psychotherapeutisches Verfahren bei Sozialer Angststörung.

Neurobiological and clinical effects of fNIRS-controlled rTMS in patients with panic disorder/agoraphobia during cognitive-behavioural therapy

BACKGROUND

A relevant proportion of patients with panic disorder (PD) does not improve even though they receive state of the art treatment for anxiety disorders such as cognitive-behavioural therapy (CBT). At the same time, it is known, that from a neurobiological point of view, PD patients are often characterised by prefrontal hypoactivation. Intermittent Theta Burst Stimulation (iTBS) is a non-invasive type of neurostimulation which can modulate cortical activity and thus has the potential to normalise prefrontal hypoactivity found in PD. We therefore aimed at investigating the effects of iTBS as an innovative add-on to CBT in the treatment for PD.

METHODS

In this double-blind, bicentric study, 44 PD patients, randomised to sham or verum stimulation, received 15 sessions of iTBS over the left prefrontal cortex (PFC) in addition to 9 weeks of group CBT. Cortical activity during a cognitive as well as an emotional (Emotional Stroop) paradigm was assessed both at baseline and post-iTBS treatment using functional near-infrared spectroscopy (fNIRS) and compared to healthy controls.

RESULTS

In this manuscript we only report the results of the emotional paradigm; for the results of the cognitive paradigm please refer to Deppermann et al. (2014). During the Emotional Stroop test, PD patients showed significantly reduced activation to panic-related compared to neutral stimuli for the left PFC at baseline. Bilateral prefrontal activation for panic-related stimuli significantly increased after verum iTBS only. Clinical ratings significantly improved during CBT and remained stable at follow-up. However, no clinical differences between the verum- and sham-stimulated group were identified, except for a more stable reduction of agoraphobic avoidance during follow-up in the verum iTBS group.

LIMITATIONS

Limitations include insufficient blinding, the missing control for possible state-dependent iTBS effects, and the timing of iTBS application during CBT.

CONCLUSION

Prefrontal hypoactivity in PD patients was normalised by add-on iTBS. Clinical improvement of anxiety symptoms was not affected by iTBS.

Influence of single-dose quetiapine on fear network activity - A pharmaco-imaging study

OBJECTIVE

Anxiety disorders are among the most frequent psychiatric disorders. Current treatment guidelines recommend antidepressants, the calcium modulator gabapentin, and benzodiazepines as pharmacological treatments. However, delayed onset of action precludes the use of antidepressants as an acute treatment, while benzodiazepines can be recommended only as an emergency treatment due to their inherent risk of dependence. Therefore, an alternative pharmacological agent with acute efficacy is needed. Preliminary evidence points towards possible anxiolytic properties of the atypical antipsychotic quetiapine. The goals of this study were to test the acute anxiolytic properties of quetiapine in patients suffering from arachnophobia in a challenge paradigm, and to assess the effects of quetiapine on the central nervous fear network.

METHODS

In a randomized, double-blind, placebo-controlled proof-of-concept study, n=58 arachnophobic patients underwent an fMRI scan while looking at phobia-related and neutral stimuli. Subjective anxiety was evaluated retrospectively in questionnaires.

RESULTS

The functional imaging data revealed that patients showed stronger amygdala activation to phobia-related than to neutral stimuli. However, no effect of quetiapine on fear network activity was detected. Further, on questionnaire measures, quetiapine significantly reduced somatic anxiety symptoms, but had no effect on general psychological anxiety.

CONCLUSION

Viewing phobic pictures resulted in a robust amygdala activation in arachnophobic patients. Quetiapine seems to have no influence on activation in anxiety-related brain areas but appears to reduce acute somatic anxiety symptoms in patients with specific phobia. The central nervous correlates of the anxiolytic effects of quetiapine remain to be clarified in future studies.

Diaphragmatic breathing during virtual reality exposure therapy for aviophobia: functional coping strategy or avoidance behavior? a pilot study

BACKGROUND

Although there is solid evidence for the efficacy of in vivo and virtual reality (VR) exposure therapy for a specific phobia, there is a significant debate over whether techniques promoting distraction or relaxation have impairing or enhancing effects on treatment outcome. In the present pilot study, we investigated the effect of diaphragmatic breathing (DB) as a relaxation technique during VR exposure treatment.

METHOD

Twenty-nine patients with aviophobia were randomly assigned to VR exposure treatment either with or without diaphragmatic breathing (six cycles per minute). Subjective fear ratings, heart rate and skin conductance were assessed as indicators of fear during both the exposure and the test session one week later.

RESULTS

The group that experienced VR exposure combined with diaphragmatic breathing showed a higher tendency to effectively overcome the fear of flying. Psychophysiological measures of fear decreased and self-efficacy increased in both groups with no significant difference between the groups.

CONCLUSIONS

Our findings indicate that diaphragmatic breathing during VR exposure does not interfere with the treatment outcome and may even enhance treatment effects of VR exposure therapy for aviophobic patients.

TRIAL REGISTRATION

Retrospectively registered. ClinicalTrials.gov NCT02990208 . Registered 07 December 2016.

The impact of perception and presence on emotional reactions: a review of research in virtual reality

Virtual reality (VR) has made its way into mainstream psychological research in the last two decades. This technology, with its unique ability to simulate complex, real situations and contexts, offers researchers unprecedented opportunities to investigate human behavior in well controlled designs in the laboratory. One important application of VR is the investigation of pathological processes in mental disorders, especially anxiety disorders. Research on the processes underlying threat perception, fear, and exposure therapy has shed light on more general aspects of the relation between perception and emotion. Being by its nature virtual, i.e., simulation of reality, VR strongly relies on the adequate selection of specific perceptual cues to activate emotions. Emotional experiences in turn are related to presence, another important concept in VR, which describes the user’s sense of being in a VR environment. This paper summarizes current research into perception of fear cues, emotion, and presence, aiming at the identification of the most relevant aspects of emotional experience in VR and their mutual relations. A special focus lies on a series of recent experiments designed to test the relative contribution of perception and conceptual information on fear in VR. This strand of research capitalizes on the dissociation between perception (bottom–up input) and conceptual information (top-down input) that is possible in VR. Further, we review the factors that have so far been recognized to influence presence, with emotions (e.g., fear) being the most relevant in the context of clinical psychology. Recent research has highlighted the mutual influence of presence and fear in VR, but has also traced the limits of our current understanding of this relationship. In this paper, the crucial role of perception on eliciting emotional reactions is highlighted, and the role of arousal as a basic dimension of emotional experience is discussed. An interoceptive attribution model of presence is suggested as a first step toward an integrative framework for emotion research in VR. Gaps in the current literature and future directions are outlined.

Virtual reality exposure in anxiety disorders: impact on psychophysiological reactivity

OBJECTIVES

Anxiety disorders are among the most frequently encountered psychiatric disorders. Recommended treatments include cognitive behavioural therapy (CBT) and/or medication. In recent years, beneficial effects of virtual reality (VR) exposure therapy have been shown, making this technique a promising addition to CBT. However, the ability of VR to mimic threatening stimuli in a way comparable to in vivo cues has been discussed. In particular, it has been questioned whether VR is capable of provoking psychophysiological symptoms of anxiety. Since psychophysiological arousal is considered a prerequisite for effective exposure treatment, this systematic review aims to evaluate the evidence for the potential of VR exposure to evoke and modulate psychophysiological fear reactions.

METHODS

PubMed and PsycINFO/Academic Search Premier databases were searched. Thirty-eight studies investigating challenge or habituation effects were included.

RESULTS

VR exposure does provoke psychophysiological arousal, especially in terms of electrodermal activity. Results on psychophysiological habituation in VR are inconclusive. Study design and methodological rigour vary widely.

CONCLUSIONS

Despite several limitations, this review provides evidence that VR exposure elicits psychophysiological fear reactions in patients and healthy subjects, rendering VR a promising treatment for anxiety disorders, and a potent research tool for future investigations of psychophysiological processes and their significance during exposure treatment.

Spatial and temporal variability of source contributions to ambient PM10 during winter in Augsburg, Germany using organic and inorganic tracers

Daily PM10 samples were collected during a one-month sampling campaign from February 13 to March 12, 2008 at eight different sampling sites in Augsburg, Southern Germany. Source apportionment was performed to identify the main sources and related contributions by analysis of organic and inorganic tracers. Nine factors were separated comprising: solid fuel combustion, traffic-related emissions, secondary inorganics, and mixed sources. Spatiotemporal variation of the source contributions was evaluated using the Pearson correlation coefficient (r) and coefficient of divergence (COD). All factors (except hopanes and mixed sources) showed moderate to high (0.6<r>0.8) correlation coefficients between the eight sites and were distributed heterogeneously. Secondary sulfate and secondary nitrate factors were relatively more uniformly distributed (compared to other factors) with lower medians of COD value (0.47 and 0.56, respectively) and higher correlation values (r=0.97 and 0.85, respectively). The maximum daily average contribution for coal & wood combustion factor was observed at the LfU suburban site (4.0 μg m(-3)); wood combustion factor at the LSW residential site (5.1 μg m(-3)) ; diesel & fuel oil consumption factor at the Bifa suburban and BP urban sites (both 2.5 μg m(-3)); road dust & tram factor at the KP traffic site (16.2 μg m(-3)) and the BP urban site (6.6 μg m(-3)); hopanes factor at the BP urban and Bifa suburban sites (both 0.7 μg m(-3)); and de-icing NaCl factor at the KP traffic site (4.8 μg m(-3)). Secondary sulfate and secondary nitrate factors had approximately similar contributions (6.2 μg m(-3) and 4.3 μg m(-3), respectively) at all sites. Mixed sources factor had the highest daily average contribution to PM10 mass at the KP traffic site (7.0 μg m(-3)).

Does rTMS alter neurocognitive functioning in patients with panic disorder/agoraphobia? An fNIRS-based investigation of prefrontal activation during a cognitive task and its modulation via sham-controlled rTMS

OBJECTIVES

Neurobiologically, panic disorder (PD) is supposed to be characterised by cerebral hypofrontality. Via functional near-infrared spectroscopy (fNIRS), we investigated whether prefrontal hypoactivity during cognitive tasks in PD-patients compared to healthy controls (HC) could be replicated. As intermittent theta burst stimulation (iTBS) modulates cortical activity, we furthermore investigated its ability to normalise prefrontal activation.

METHODS

Forty-four PD-patients, randomised to sham or verum group, received 15 iTBS-sessions above the left dorsolateral prefrontal cortex (DLPFC) in addition to psychoeducation. Before first and after last iTBS-treatment, cortical activity during a verbal fluency task was assessed via fNIRS and compared to the results of 23 HC.

RESULTS

At baseline, PD-patients showed hypofrontality including the DLPFC, which differed significantly from activation patterns of HC. However, verum iTBS did not augment prefrontal fNIRS activation. Solely after sham iTBS, a significant increase of measured fNIRS activation in the left inferior frontal gyrus (IFG) during the phonological task was found.

CONCLUSION

Our results support findings that PD is characterised by prefrontal hypoactivation during cognitive performance. However, verum iTBS as an "add-on" to psychoeducation did not augment prefrontal activity. Instead we only found increased fNIRS activation in the left IFG after sham iTBS application. Possible reasons including task-related psychophysiological arousal are discussed.

Acute anxiolytic effects of quetiapine during virtual reality exposure--a double-blind placebo-controlled trial in patients with specific phobia

Anxiety disorders are among the most frequent psychiatric disorders. With regard to pharmacological treatment, antidepressants, the calcium modulator pregabalin and benzodiazepines are recommended according to current treatment guidelines. With regard to acute states of anxiety, so far practically only benzodiazepines provide an immediate anxiolytic effect. However, the risk of tolerance and dependency limits the use of this class of medication. Therefore, there is still a need for alternative pharmacologic strategies. Increasing evidence points towards anxiety-reducing properties of atypical antipsychotics, particularly quetiapine. Therefore, we aimed to evaluate the putative acute anxiolytic effects of this compound, choosing the induction of acute anxiety in patients with specific phobia as a model for the evaluation of ad-hoc anxiolytic properties in a proof-of-concept approach. In a randomized, double-blind, placebo-controlled study, 58 patients with arachnophobia were treated with a single dose of quetiapine XR or placebo prior to a virtual reality spider challenge procedure. Treatment effects were monitored using rating scales for acute anxiety as well as measurements of heart rate and skin conductance. Overall, quetiapine showed significant anxiolytic effects compared to placebo. However, effects were not seen on the primary outcome measure (VAS Anxiety), but were limited to somatic anxiety symptoms. Additionally, a significant reduction of skin conductance was observed. Further exploratory analyses hint towards a mediating role of the (COMT) val158met genotype on treatment response. The present results thus suggest a possible suitability of quetiapine in the acute treatment of anxiety, particularly with regard to somatic symptoms.

Acute shift in glutamate concentrations following experimentally induced panic with cholecystokinin tetrapeptide--a 3T-MRS study in healthy subjects

According to preclinical studies, glutamate has been implicated in the pathogenesis of anxiety. In order to elucidate the role of glutamate in anxiety and panic in humans, brain glutamate+glutamine (Glx) levels were measured during cholecystokinin-tetrapeptide (CCK-4)-induced panic using magnetic resonance spectroscopy (MRS). Eighteen healthy subjects underwent a CCK-4 challenge. MR spectra were obtained from the anterior cingulate cortex (ACC) using a single voxel point-resolved spectroscopy method and analyzed using LCModel. A combined fitting of Glx was performed. Panic was assessed using the Acute Panic Inventory (API) and Panic Symptom Scale (PSS) scores. Moreover, hypothalamic-pituitary-adrenal axis stimulation was monitored throughout the challenge. There was a significant panic response following CCK-4 as revealed by a marked increase in both the panic scores (API: F(1,17)=149.41; p<0.0001; PSS: F(1,17)=88.03; p<0.0001) and heart rate (HR: F(1,17)=72.79; p<0.0001). MRS measures showed a significant increase of brain Glx/creatine (Glx/Cr) levels peaking at 2-10 min after challenge (F(1,17)=15.94; p=0.001). There was also a significant increase in CCK-4-related cortisol release (F(6,11)=8.68; p=0.002). Finally, significant positive correlations were found between baseline Glx/Cr and both APImax (r=0.598; p=0.009) and maximum heart rate (HR(max)) during challenge (r=0.519; p=0.027). Our results suggest that CCK-4-induced panic is accompanied by a significant glutamate increase in the bilateral ACC. The results add to the hypothesis of a disturbance of the inhibitory-excitatory equilibrium and suggest that apart from static alterations rapid and dynamic neurochemical changes might also be relevant for the neural control of panic attacks.

Flow Visualisation in Co-rotating Twin Screw Extruders: Positron Emission Particle Tracking and Numerical Particle Trajectories

Co-rotating twin-screw extruders are widely used compounding machines. They are mainly configured based on extensive experience and iterative approaches to optimise output and composite quality. The visualisation technology developed in the EU-project PEPTFlow allows visualisation of composite flow in twin-screw extruders under realistic processing conditions by tracking radioactive tracer particles in the polymer melt, using a specially developed camera system. This new approach allows polymer flow to be studied in different screw elements and screw configurations under realistic compounding conditions at normal temperatures and melt pressures. The paper presents the latest developments in the camera systems as well as the different ways to use and interpret the results. Detailed analysis of residence times and residence time distributions for standard compound screw elements, like kneading discs, conveying elements and reverse elements are presented. In addition for a better understanding of the flow field inside twin-screw extruders, numerical particle tracking is done. The Stokes equation, using XFEM method, are solved and the numerical RTD's (residence time distribution) are compared for various screw designs.

Differences in saccadic eye movements in subjects at high and low risk for panic disorder

BACKGROUND

Panic disorder (PD) has a strong genetic component showing high heritability rates and familial aggregation. Moreover, there is evidence for associations between parental PD and patterns of psychopathology. So far, little is known about possible endophenotypes representing premorbid vulnerability markers in high-risk subjects for PD. In the present study, we investigated saccadic eye movement (SEM) as an index of CNS inhibitory function in subjects at high risk for PD.

METHODS

132 healthy children at high and low familial risk for PD were included in the study. Basal SEM parameters were obtained using an electro-oculography (EOG) based system measuring peak saccadic eye velocity (pSEV), latency and accuracy. Moreover, with regard to self rating scales, state-trait-anxiety (STAI-C), childhood behavioral inhibition (CSRI), and anxiety sensitivity (CASI) were assessed.

RESULTS

There was a significant overall difference for basal SEM parameters across groups as revealed by MANCOVA (F7,118=2.184, p=.040). A significant influence was found for the covariate age, while gender and puberty status had no influence on SEM. High-risk (HR) subjects showed significantly lower pSEV. Moreover, levels of state and trait anxiety were higher in HR children (F1=5.429, p=.021).

DISCUSSION

In our sample, measurement of pSEV allowed discrimination between children at high and low risk for PD. Since these results argue for possible alterations of saccadic function in high risk subjects, differences in underlying neurobiological mechanisms might be discussed as a possible endophenotype of PD.

Occurence of ultra-rapid cycling during electroconvulsive therapy in bipolar depression

BACKGROUND

Treatment of bipolar depression with antidepressants has often been reported to be associated with a certain risk of rapid cycling (RC). Also, non-pharmacological treatment approaches such as sleep deprivation or light therapy can induce affective shifts. Moreover, during electroconvulsive therapy (ECT), which is considered a powerful antidepressant treatment, manic switches and episodes of rapid cycling can occur.

METHODS

Here we report the case of a 66-year-old female patient with bipolar depression, who underwent electroconvulsive therapy because of a therapy-refractory depressive episode.

RESULTS

During ECT, highly frequent mood alternations were observed, fulfilling the criteria of ultra rapid cycling (URC). These symptoms were successfully treated with lithium carbonate while ECT was continued.

CONCLUSION

To our knowledge, this is the first case report of URC during ECT. URC might be considered a rare but potential side effect of ECT. In our case, lithium was used successfully for the treatment of URC and might be suggested in similar cases, where anticonvulsants are not the first choice of treatment. However, in view of the risk of cognitive side effects the combination of ECT and lithium requires a careful clinical monitoring.

COMT val158met influence on electroconvulsive therapy response in major depression

There is strong evidence for a genetic contribution to the pathogenesis of depression, with the functional catechol-O-methyltransferase (COMT) val158met polymorphism having been suggested as a potential susceptibility factor. In the present study, the effect of COMT val158met on response to electroconvulsive therapy (ECT) was analyzed in a sample of 104 Caucasian patients (f = 71, m = 33) with pharmacologically treatment-resistant Major Depression. The higher active COMT 158val allele was found to be associated with (1) higher pre-ECT severity of depression and (2) better treatment response to ECT particularly regarding the core symptoms of depression as well as sleep-related symptoms. These findings were restricted to the female subgroup of patients. In summary, the present study supports a potentially gender-specific significant impact of COMT gene variation on electroconvulsive therapy response, with COMT 158val risk allele carriers suffering from more severe, pharmacologically less efficiently treatable depression and thus possibly deriving greater benefit from ECT in the first place.

Comparison of combined psycho- and pharmacotherapy with monotherapy in anxiety disorders: controversial viewpoints and clinical perspectives

Anxiety disorders are among the most frequent psychiatric disorders. Experimental evidence supports both psychotherapy as well as pharmacotherapy as effective treatments. There is, however, a controversy concerning the efficacy of a combination of both approaches. While some studies suggest that combined treatment enhances efficacy, others report conflicting results. This article traces the positions in this debate. We present the results from two recent meta-analyses and discuss implications for clinical practice and further research. We suggest that a research strategy that strives to establish differential indications based on patient characteristics should be preferred over attempts to reach a global judgement of the question, which appears too simplistic given the complexity of the issue.

Contribution to the certification of B, Cd, Cu, Mg and Pb in a synthetic water sample, by use of isotope-dilution ICP-MS, for Comparison 12 of the International Measurement Evaluation Programme

The contribution of the Institute for Reference Materials and Measurements to the certification of the B, Cd, Cu, Mg, and Pb content of a synthetic water sample used in Comparison 12 of the International Measurement Evaluation Programme (IMEP-12) is described. The aim of the IMEP programme is to demonstrate objectively the degree of equivalence and quality of chemical measurements of individual laboratories on the international scene by comparing them with reference ranges traceable to the SI (Système International d'Unités). IMEP is organized in support of European Union policies and helps to improve the traceability of values produced by field chemical measurement laboratories. The analytical procedure used to establish the reference values for the B, Cd, Cu, Mg, and Pb content of the IMEP-12 sample is based on inductively coupled plasma-isotope-dilution mass spectrometry (ICP-IDMS) applied as a primary method of measurement. The measurements performed for the IMEP-12 study are described in detail. Focus is on the element boron, which is particularly difficult to analyze by ICP-MS because of potential problems of low sensitivity, high mass discrimination, memory effects, and abundance sensitivity. For each of the certified amount contents presented here a total uncertainty budget was calculated using the method of propagation of uncertainties according to ISO (International Organization for Standardization) and Eurachem guidelines. For all investigated elements with concentrations in the low micro g kg(-1) and mg kg(-1) range (corresponding to pmol kg(-1) to the high micro mol kg(-1) level), SI-traceable reference values with relative expanded uncertainties ( k=2) of less than 2 % were obtained.

SI-traceable certification of the amount content of cadium below the ng g(-1) level in blood samples by isotope dilution ICP-MS applied as a primary method of measurement

The development and implementation of a method for the certification of cadmium in blood samples at low ng g(-1) and sub ng g(-1) levels is described. The analytical procedure is based on inductively coupled plasma isotope dilution mass spectrometry (ICP-IDMS) applied as a primary method of measurement. Two different sample digestion methods, an optimized microwave digestion procedure using HNO3 and H2O2 as oxidizing agents and a high-pressure asher digestion procedure, were developed and compared. The very high salt content of the digests and the high molybdenum content, which can cause oxide-based interferences with the Cd isotopes, were reduced by a chromatographic matrix separation step using an anion-exchange resin. All isotope ratio measurements were performed by a quadrupole ICP-MS equipped with an ultrasonic nebulizer with membrane desolvator. This sample introduction set-up was used to increase sensitivity and minimize the formation of oxides (less MoO+ interference with the Cd isotopes). Because of the very low Cd concentrations in the samples and the resulting need to minimize the procedural blank as much as possible, all sample-processing steps were performed in a clean room environment. Detection limits of 0.005 ng g(-1) Cd were achieved using sample weights of 2.7 g. The method described was used to recertify the cadmium content of three different blood reference materials from the Community Bureau of Reference (BCR) of the European Commission (BCR-194, BCR-195, BCR- 196). Cadmium concentrations ranged between approximately 0.2 ng g(-1) and approximately 12 ng g(-1). For these materials, SI-traceable certified values including total uncertainty budgets according to ISO and Eurachem guidelines were established.

Development of an ICP-IDMS method for accurate routine analyses of toxic heavy metals in polyolefins and comparison with results by TI-IDMS

An inductively coupled plasma isotope dilution mass spectrometric (ICP-IDMS) method was developed as a suitable method - with respect to its sensitivity, precision, accuracy, and time-consumption - for the analysis of toxic heavy metal traces (Pb, Cd, Cr, and Hg) in polyolefins. Results for Pb, Cd, and Cr were compared with those obtained by thermal ionization isotope dilution mass spectrometry (TI-IDMS), which was used as a reference method. Because of its high first ionization potential and its high volatility mercury could not be determined by TI-IDMS. A multi-element spike solution, containing isotopically enriched 206Pb, 116Cd, 53Cr, and 201Hg, was used for the isotope dilution step. Decomposition of the polyolefin samples was carried out with concentrated HNO3 at temperatures of about 300 degrees C in a high pressure asher (HPA). This procedure decomposes polyolefins completely and allows isotopic equilibration between sample and spike isotopes. Detection limits of 16 ng/g, 5 ng/g, 164 ng/g, and 9 ng/g were obtained for Pb, Cd, Cr, and Hg by ICP-IDMS using only sample weights of 0.25 g. In different commercially available polyethylene samples heavy metal concentrations in the range of < 5 ng/g to 4 x 10(3) ng/g were analyzed. Both mass spectrometric methods were applied within the EU project "Polymeric Elemental Reference Material (PERM)" for the certification of two polyethylene reference materials. The ICP-IDMS results agreed very well with those of TI-IDMS which demonstrates the accuracy of the ICP-IDMS method also suitable for routine analyses.

Should the exit of the artificial abutment tooth be positioned in the region of the attached gingiva?

The necessity of an area of attached gingiva around penetrating implants was examined in 26 patients. It was demonstrated that plaque corneal in the major factor in avoiding inflammatory reactions.

END GROUP AND SEDIMENTATION DATA ON FRAGMENTED HIGH MOLECULAR WEIGHT RIBONUCLEATES

A method for end group analysis of ribonucleate preparations using purified snake venom phosphodiesterase is described. Unusual difficulties encountered with the method are discussed. The technique is useful for detection of end groups resulting from enzymic and chemical fragmentation of high molecular weight ribonucleates. Preliminary studies indicate that the method has limited usefulness because of a spontaneous hydrolysis of ribonucleates which occurs under the conditions which are optimal for hydrolysis with snake venom phosphodiesterase (pH 9, in the presence of magnesium). Physicochemical studies have shown that the pronounced dependence of sedimentation coefficient on ionic strength which has been reported by other investigators is also observed with fragmented high molecular weight ribonucleates and with 16S + 24S ribonucleates of Ehrlich ascites cells. The changes of sedimentation rate are associated with configurational and aggregation effects.