PubMed Health⌕ Search

Biomedical subjects

Walton T Roth

Publications and source records attributed to Walton T Roth.

At least 19 recordsLinked to original sources
PubMed2006

The Driving Cognitions Questionnaire: development and preliminary psychometric properties.

Recent research has suggested that fear of driving is common in the general population. People may have various concerns when driving, and instruments for the assessment of these concerns are lacking. The present paper describes the development and preliminary evaluation of the Driving Cognitions Questionnaire (DCQ). The DCQ is a 20-item scale that measures three areas of driving-related concerns--panic-related, accident-related, and social concerns. In three separate samples from different countries (n=69, 100, and 78), the scale showed good internal consistency and substantial correlations with measures of the severity of driving fear. It discriminated well between people with and without driving phobia. It also showed convergent validity with other measures. The questionnaire shows promise for use in research and clinical practice.

Accidents, Traffic↗
PubMed2006

Muscle relaxation therapy for anxiety disorders: it works but how?

Muscle relaxation therapy (MRT) has continued to play an important role in the modern treatment of anxiety disorders. Abbreviations of the original progressive MRT protocol [Jacobson, E. (1938). Progressive relaxation (2nd ed.). Chicago: University of Chicago Press] have been found to be effective in panic disorder (PD) and generalized anxiety disorder (GAD). This review describes the most common MRT techniques, summarizes recent evidence of their effectiveness in treating anxiety, and explains their rationale and physiological basis. We conclude that although GAD and PD patients may exhibit elevated muscle tension and abnormal autonomic and respiratory measures during laboratory baseline assessments, the available evidence does not allow us to conclude that physiological activation decreases over the course of MRT in GAD and PD patients, even when patients report becoming less anxious. Better-designed studies will be required to identify the mechanisms of MRT and to advance clinical practice.

Anxiety Disorders↗
PubMed2006

Distinguishing emotional from physical activation in ambulatory psychophysiological monitoring.

Ambulatory monitoring has gained powerful new tools due to recent electronic and computer advances. The capability simultaneously to monitor numerous physiological parameters and behavior enhances the ecological validity of field assessment, but methodological challenges abound that can compromise attempts to understand biobehavioral relations in the real world. A major obstacle is that physiological dysregulation or emotion effects can be masked by variation in physical activity. Using a multi-channel ambulatory recording system, a wide array of self-report, physiological and environmental measurements was collected from 28 participants during quiet sitting, physical exercise and an emotion induction consisting of a short commercial flight. Half of the participants were selected to respond to flying with intense anxiety, the other half, with moderate excitement. Recorded channels included ECG, EDA, calibrated respiration pattern, and skin temperature, from which 17 physiological parameters were calculated. Accelerometry and self-report in an emotion diary served as manipulation checks. Results indicate that many parameters, including heart rate, respiratory sinus arrhythmia, and skin conductance level and its fluctuation rate, were strongly and nonspecifically affected by both anxiety and exercise. However, parameters of respiratory volume were particularly responsive to exercise, while certain parameters of irregularity in breathing were to anxiety. Several respiratory timing parameters were responsive to both exercise and excitement. We conclude that physiological measures provide information helping to distinguish emotional from physical activation. However, additional context awareness is necessary for confident data interpretation in ambulatory recording. This can be achieved by specific channels such as accelerometry, items in an electronic diary, semi-structured protocols, and statistical modeling.

Diagnosis, Computer-Assisted↗
PubMed2005

Panic attack symptom dimensions and their relationship to illness characteristics in panic disorder.

Subtyping panic disorder by predominant symptom constellations, such as cognitive or respiratory, has been done for some time, but criteria have varied considerably between studies. We sought to identify statistically symptom dimensions from intensity ratings of 13 DSM-IV panic symptoms in 343 panic patients interviewed with the Anxiety Disorders Interview Schedule for DSM-IV Lifetime Version. We then explored the relation of symptom dimensions to selected illness characteristics. Ratings were submitted to exploratory maximum likelihood factor analysis with a Promax rotation. A three-factor solution was found to account best for the variance. Symptoms loading highest on the first factor were palpitations, shortness of breath, choking, chest pain, and numbness, which define a cardio-respiratory type (with fear of dying). Symptoms loading highest on the second factor were sweating, trembling, nausea, chills/hot flashes, and dizziness, which defines a mixed somatic subtype. Symptoms loading highest on the third factor were feeling of unreality, fear of going crazy, and fear of losing control, which defines a cognitive subtype. Subscales based on these factors showed moderate intercorrelations. In a series of hierarchical multiple regression analyses, the cardio-respiratory subscale was a strong predictor of panic severity, frequency of panic attacks, and agoraphobic avoidance, while the cognitive subscale mostly predicted worry due to panic. In addition, patients with comorbid asthma had higher scores on the cardio-respiratory subscale. We conclude that partly independent panic symptom dimensions can be identified that have different implications for severity and control of panic disorder.

Adult↗
PubMed2005

Physiological markers for anxiety: panic disorder and phobias.

Physiological activation is a cardinal symptom of anxiety, although physiological measurement is still not used for psychiatric diagnosis. An ambulatory study of phobics who were afraid of highway driving showed a concordance between self-reported anxiety during driving, autonomic activation, hypocapnia, and sighing respiration. Patients with panic attacks do not exhibit autonomic activation when they are quietly sitting and not having panic attacks, but do have the same respiratory abnormalities as driving phobics, suggesting that these abnormalities could be a marker for panic disorder. Such abnormalities are compatible with both the false suffocation alarm (D. Klein) and hyperventilation (R. Ley) theories of panic. Hypocapnia, however, is often absent during full-blown panic attacks. Since activation functions as preparation for physical activity, it may not occur when a patient has learned that avoidance of fear by flight or fight is futile. We developed a capnometry feedback assisted breathing training therapy for panic disorder designed to reduce hyperventilation and making breathing regular. Without feedback, conventional therapeutic breathing instructions may actually increase hyperventilation by increasing dyspnea. Five weekly therapy sessions accompanied by daily home practice with a capnometer produced marked clinical improvement compared to changes in an untreated group. Improvement was sustained over a 12-month follow-up period. The therapist avoided any statements or procedures designed to alter cognitions. Improvement occurred regardless of whether patients initially reported mostly respiratory or non-respiratory symptoms during their attacks. There is evidence that modifying any of the three systems comprising a fear network can be therapeutic, as exemplified by cognitive therapy modifying thoughts, exposure therapy modifying avoidance, and breathing training procedures modifying pCO(2).

Anxiety↗
PubMed2005

Voluntary hyperventilation in the treatment of panic disorder--functions of hyperventilation, their implications for breathing training, and recommendations for standardization.

Hyperventilation has numerous theoretical and empirical links to anxiety and panic. Voluntary hyperventilation (VH) tests have been applied experimentally to understand psychological and physiological mechanisms that produce and maintain anxiety, and therapeutically in the treatment of anxiety disorders. From the theoretical perspective of hyperventilation theories of anxiety, VH is useful diagnostically to the clinician and educationally to the patient. From the theoretical perspective of cognitive-behavior therapy, VH is a way to expose patients with panic disorder to sensations associated with panic and to activate catastrophic cognitions that need restructuring. Here we review panic disorder treatment studies using breathing training that have included VH. We differentiate the roles of VH in diagnosis, education about symptoms, training of breathing strategies, interoceptive exposure, and outcome measurement--discussing methodological issues specific to these roles and VH test reliability and validity. We propose how VH procedures might be standardized in future studies.

Anxiety Disorders↗
PubMed2005

Psychophysiological assessment during exposure in driving phobic patients.

A comprehensive assessment of fear or anxiety requires measurement of both self-report and physiological responses. Respiratory abnormalities have been rarely examined during real-life exposure, although they are an integral part of fear. Twenty-one women with a specific driving phobia and 17 nonphobic women were psychophysiologically monitored during 2 highway-driving sessions; phobic women completed an additional session. Respiratory movements, end-tidal partial pressure of carbon dioxide, an electrocardiogram, skin conductance, and skin temperature were recorded. Phobic patients differed from control participants both physiologically and experientially before, during, and after exposure. Effect size during exposure was large for the authors' measure of hyperventilation. Discriminant analysis indicated that multiple physiological measures contributed nonredundant information and correctly classified 95% of phobic and control participants. Thus, selected respiratory and autonomic measures are valid diagnostic and therapeutic outcome criteria for this situational phobia.

Adult↗
PubMed2005

Are current theories of panic falsifiable?

The authors examine 6 theories of panic attacks as to whether empirical approaches are capable of falsifying them and their heuristic value. The authors conclude that the catastrophic cognitions theory is least falsifiable because of the elusive nature of thoughts but that it has greatly stimulated research and therapy. The vicious circle theory is falsifiable only if the frightening internal sensations are specified. The 3-alarms theory postulates an indeterminate classification of attacks. Hyperventilation theory has been falsified. The suffocation false alarm theory lacks biological parameters that unambiguously index dyspnea or its distinction between anticipatory and panic anxiety. Some correspondences postulated between clinical phenomena and brain areas by the neuroanatomical hypothesis may be falsifiable if panic does not depend on specific thoughts. All these theories have heuristic value, and their unfalsifiable aspects are capable of modification.

Cognition↗
PubMed2005

Assessment of heart rate variability during alterations in stress: complex demodulation vs. spectral analysis.

Complex demodulation (CDM) has been proposed as a method for the analysis of high- and low-frequency variabilities of heart rate and blood pressure under non-stationary conditions. In contrast to power spectral analysis, CDM provides time-dependent changes in signal amplitude and frequency on a continuous basis and may yield insights into short-term alterations in autonomic regulation. In particular, CDM may be uniquely suited for quantifying changes in respiratory sinus arrhythmia (RSA) at the onset of acute physical or mental stress conditions. In a simulation analysis we generated R-R interval time series within a normal physiological range that represented different typical sources of non-stationarity present during varying stress. Sources of non-stationarity included abrupt changes in a) mean level (from 1000 to 500 ms within 60 sec), b) oscillatory amplitude (from 50 to 10 ms), c) oscillatory frequency (from 0.2 to 0.4 Hz), and d) a combination of the above. In general, CDM-estimated amplitude and frequency accurately reproduced characteristics of the simulation data under all conditions, even after substantial noise and a 0.09 Hz oscillation were added. However, during some transitions CDM estimates fluctuated around the true values for up to 15 sec before they stabilized. Compared to CDM, power spectral analysis results were less informative since they did not allow the disentangling of unique contributions of distinct amplitudes and frequencies at different time points. Our analyses indicate that CDM provides a powerful means of continuously assessing time-dependent changes in RSA during varying physical or mental stress. CDM may also hold promise for a range of physiological and environmental non-steady state conditions where rapid dynamic alterations in autonomic control are likely to occur.

Algorithms↗
PubMed2004

Respiratory feedback for treating panic disorder.

Panic disorder patients often complain of shortness of breath or other respiratory complaints, which has been used as evidence for both hyperventilation and false suffocation alarm theories of panic. Training patients to change their breathing patterns is a common intervention, but breathing rarely has been measured objectively in assessing the patient or monitoring therapy results. We report a new breathing training method that makes use of respiratory biofeedback to teach individuals to modify four respiratory characteristics: increased ventilation (Respiratory Rate x Tidal Volume), breath-to-breath irregularity in rate and depth, and chest breathing. As illustrated by a composite case, feedback of respiratory rate and end-tidal pCO2 can facilitate voluntary control of respiration and reduce symptoms. Respiratory monitoring may provide relevant diagnostic, prognostic, and outcome information.

Biofeedback, Psychology↗
PubMed2004

Behavioral interventions in asthma: biofeedback techniques.

OBJECTIVES: Biofeedback techniques have long been recommended as an adjunctive treatment for bronchial asthma. Techniques that target lung function directly, or indirectly by altering facial muscle tension, heart rate, heart rate variability (HRV) or inspiratory volume together with accessory muscle tension, have been proposed. We review evidence for the effectiveness of these biofeedback interventions and discuss the psychophysiological rationale behind individual techniques. METHOD: Controlled studies of biofeedback in asthma were retrieved using relevant search engines and reference lists of published articles. Effect sizes comparing intervention with control groups were calculated where appropriate. RESULTS: Most of the studies suffer from methodological inadequacies or poor reporting of methods and results. Interventions targeting respiratory resistance directly have yielded only small and inconsistent changes in lung function and are difficult to implement without producing dynamic hyperinflation. Biofeedback-assisted facial muscle relaxation as an indirect intervention has yielded mixed results across studies, with only half of the studies showing significant albeit very small and clinically irrelevant improvements in lung function. The underlying physiological assumptions of the technique are questionable in the light of current knowledge of respiratory physiology. For other indirect techniques, only preliminary evidence of small effects is available. CONCLUSION: Currently, there is little good evidence that biofeedback techniques can contribute substantially to the treatment of asthma.

Asthma↗
PubMed2003

Selective attention in anxiety: distraction and enhancement in visual search.

According to cognitive models of anxiety, anxiety patients exhibit an attentional bias towards threat, manifested as greater distractibility by threat stimuli and enhanced detection of them. Both phenomena were studied in two experiments, using a modified visual search task, in which participants were asked to find single target words (GAD-related, speech-related, neutral, or positive) hidden in matrices made up of distractor words (also GAD-related, speech-related, neutral, or positive). Generalized anxiety disorder (GAD) patients, social phobia (SP) patients afraid of giving speeches, and healthy controls participated in the visual search task. GAD patients were slowed by GAD-related distractor words but did not show statistically reliable evidence of enhanced detection of GAD-related target words. SP patients showed neither distraction nor enhancement effects. These results extend previous findings of attentional biases observed with other experimental paradigms.

Adolescent↗
PubMed2003

Embarrassment and social phobia: the role of parasympathetic activation.

The few studies on the psychophysiology of embarrassment have suggested involvement of parasympathetic activation. However, blushing, the hallmark of embarrassment and a prominent symptom in social phobia, is more likely to be produced by cervical sympathetic outflow. Hitherto, there has been no evidence of parasympathetic innervation of the facial blood vessels. In this study, a group of social phobics and control participants watched, together with a 2-person audience, a previously made videotape of themselves singing a children's song. Self-report measures confirmed that this task induced embarrassment. While two measures of respiratory sinus arrhythmia (RSA) during the task did not indicate heightened parasympathetic tone, increased heart rate (HR) and skin conductance marked sympathetic activation. Thus, our data do not support the notion that an increase in parasympathetic activation plays a significant role in social phobia and embarrassment. Social anxiety and embarrassment both resulted in sympathetic activation.

Adult↗
PubMed2003

The lifeShirt. An advanced system for ambulatory measurement of respiratory and cardiac function.

An accurate ambulatory breathing monitor is needed to observe acute respiratory changes in patients with medical or psychological disorders outside the clinic (e.g., hyperventilation during panic or apneas during sleep). Significant limitations of existing monitors are size, troublesome operation, and difficulty holding chest and abdomen bands in place during 24-hour recordings. Recently, a garment has been developed with embedded inductive plethysmography sensors for continuous ambulatory monitoring of respiration, heart activity, inductive cardiography, motility, postural changes, and other functions. The signals are displayed and stored on a handheld computer (Visor), and then analyzed offline, extracting more than 40 clinical parameters relating to cardiorespiratory function (e.g., heart rate, respiratory sinus arrhythmia, tidal volume, stroke volume, pre-ejection period, apnea-hypopnea index, thoraco-abdominal coordination, sighing). The device also serves as an electronic diary of symptoms, moods, and activities. This advanced system may open a new era in ambulatory monitoring for clinical practice and scientific research.

Anxiety Disorders↗
PubMed2003

Behavioral interventions in asthma. Breathing training.

Breathing exercises are frequently recommended as an adjunctive treatment for asthma. A review of the current literature found little that is systematic documenting the benefits of these techniques in asthma patients. The physiological rationale of abdominal breathing in asthma is not clear, and adverse effects have been reported in chronic obstructive states. Theoretical analysis and empirical observations suggest positive effects of pursed-lip breathing and nasal breathing but clinical evidence is lacking. Modification of breathing patterns alone does not yield any significant benefit. There is limited evidence that inspiratory muscle training and hypoventilation training can help reduce medication consumption, in particular beta-adrenergic inhaler use. Breathing exercises do not seem to have any substantial effect on parameters of basal lung function. Additional research is needed on the psychological and physiological mechanisms of individual breathing techniques in asthma, differential effects in subgroups of asthma patients, and the generalization of training effects on daily life.

Asthma↗
PubMed2003

Breathing training for treating panic disorder. Useful intervention or impediment?

Breathing training (BT) is commonly used for treatment of panic disorder. We identified nine studies that reported the outcome of BT. Overall, the published studies of BT are not sufficiently compelling to allow an unequivocal judgment of whether such techniques are beneficial. This article discusses problems with the underlying rationale, study design, and techniques used in BT, and it identifies factors that may have determined therapy outcomes. The idea that hypocapnia and respiratory irregularities are underlying factors in the development of panic implies that these factors should be monitored physiologically throughout therapy. Techniques taught in BT must take account of respiration rate and tidal volume in the regulation of blood gases (pCO2). More studies are needed that are designed to measure the efficacy of BT using an adequate rationale and methodology. Claims that BT should be rejected in favor of cognitive or other forms of intervention are premature.

Breathing Exercises↗
PubMed2003

Detection of speaking with a new respiratory inductive plethysmography system.

The LifeShirt system, a garment with integrated sensors connected to a handheld computer, allows recording of a wide variety of clinically important cardiorespiratory data continuously for extended periods outside the laboratory or clinic. The device includes sensors for assessment of physical activity and posture since both can affect physiological activation and need to be controlled. Speaking is another potential confounding factor in the interpretation of physiological data. Auditory speech recording is problematic because it can pick up sources other than the person's voice (external microphone) or is obtrusive (throat microphone). The abdominal and thoracic calibrated respiratory inductive plethysmography (RIP) sensors integrated in the LifeShirt system might be an adequate alternative for detecting speech. In a laboratory experiment we determined respiratory parameters indicative of speech. Eighteen subjects were instructed to sit quietly, write, and speak continuously, for 4 min each. Nine parameters were derived from the RIP signals and averaged over each minute. In addition, nine variability parameters were computed as their coefficients of breath-by-breath variation. Inspiratory/expiratory time (IE-ratio) best distinguished speaking from writing with 98% correct classification at a cutoff criterion of 0.52. This criterion was equally successful in distinguishing speaking from sitting quietly. Discriminant analyses indicated that linear combinations of IE-ratio and a variety of other parameters did not reliably improve classification accuracy across tasks and replications. These results demonstrate the high efficacy of RIP-derived IE-ratio for speech detection and suggest that auditory recording is not necessary for detection of speech in ambulatory assessment.

Adult↗