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Biomedical subjects

Steven Taylor

Publications and source records attributed to Steven Taylor.

At least 19 recordsLinked to original sources
PubMed2006

Calix[4]arene-linked bisporphyrin hosts for fullerenes: binding strength, solvation effects, and porphyrin-fullerene charge transfer bands.

A calix[4]arene scaffolding has been used to construct bisporphyrin ("jaws" porphyrin) hosts for supramolecular binding of fullerene guests. Fullerene affinities were optimized by varying the nature of the covalent linkage of the porphyrins to the calixarenes. Binding constants for C60 and C70 in toluene were explored as a function of substituents at the periphery of the porphyrin, and 3,5-di-tert-butylphenyl groups gave rise to the highest fullerene affinities (26,000 M(-1) for C60). The origin of this high fullerene affinity has been traced to differential solvation effects rather than to electronic effects. Studies of binding constants as a function of solvent (toluene < benzonitrile < dichloromethane < cyclohexane) correlate inversely with fullerene solubility, indicating that desolvation of the fullerene is a major factor determining the magnitude of binding constants. The energetics of fullerene binding have been determined in terms of DelatH and DeltaS and are consistent with an enthalpy-driven, solvation-dependent process. A direct relationship between supramolecular binding of a fullerene guest to a bisporphyrin host and the appearance of a broad NIR absorption band have been established. The energy of this band moves in a predictable manner as a function of the electronic structure of the porphyrin, thereby establishing its origin in porphyrin-to-fullerene charge transfer.

Algorithms↗
PubMed2006

Pseudo-PTSD.

Pseudo-posttraumatic stress disorder (pseudo-PTSD) refers to cases in which a patient's presentation is but a simulation of the actual clinical syndrome. The problem of pseudo-PTSD has been neglected by many clinicians and researchers, who often rely on the assumption that a patient's reported symptoms can be accepted as valid. The purpose of this article is to (a) consider the diverse causes of pseudo-PTSD, (b) emphasize the importance of the DSM-IV's guideline to rule out malingering, and (c) discuss the implications that pseudo-PTSD has for research and clinical practice.

Compensation and Redress↗
PubMed2006

Detection and management of malingering in people presenting for treatment of posttraumatic stress disorder: methods, obstacles, and recommendations.

Malingering of symptoms of posttraumatic stress disorder (PTSD) has become a growing concern, particularly in healthcare and other settings in which the diagnosis is associated with financial incentives such as disability benefits. Although there is a steadily increasing body of research on methods for detecting PTSD malingering, little has been written on the assessment and practical management of malingering in treatment settings. The present article addresses this important issue, including a review of the methods, obstacles, and possible solutions for assessing PTSD malingering, along with suggestions for managing cases in which malingering is strongly suspected.

Cognitive Behavioral Therapy↗
PubMed2006

Effects of three PTSD treatments on anger and guilt: exposure therapy, eye movement desensitization and reprocessing, and relaxation training.

This study sought to investigate the efficacy of prolonged exposure, eye movement desensitization and reprocessing, and relaxation training on trait anger and guilt and on trauma-related anger and guilt within the context of posttraumatic stress disorder (PTSD) treatment. Fifteen PTSD patients completed each treatment and were assessed at posttreatment and at 3-month follow-up. All three treatments were associated with significant reductions in all measures of anger and guilt, with gains maintained at follow-up. There were no significant treatment differences in efficacy or in the proportion of patients who worsened on anger or guilt measures over the course of treatment. Between-treatment effect sizes were generally very small. Results suggest that all three treatments are associated with reductions in anger and guilt, even for patients who initially have high levels of these emotions. However, these PTSD therapies may not be sufficient for treating anger and guilt; additional interventions may be required.

Adult↗
PubMed2006

Taxonicity of anxiety sensitivity: a multi-national analysis.

Taxometric coherent cut kinetic analyses were used to test the latent structure of anxiety sensitivity in samples from North America (Canada and United States of America), France, Mexico, Spain, and The Netherlands (total n = 2741). Anxiety sensitivity was indexed by the 36-item Anxiety Sensitivity Index--Revised (ASI-R; [J. Anxiety Disord. 12(5) (1998) 463]). Four manifest indicators of anxiety sensitivity were constructed using the ASI-R: fear of cardiovascular symptoms, fear of respiratory symptoms, fear of publicly observable anxiety reactions, and fear of mental incapacitation. Results from MAXCOV-HITMAX, internal consistency tests, analyses of simulated Monte Carlo data, and a MAMBAC external consistency test indicated that the latent structure of anxiety sensitivity was taxonic in each of the samples. The estimated base rate of the anxiety sensitivity taxon differed slightly between nations, ranging from 11.5 to 21.5%. In general, the four ASI-R based manifest indicators showed high levels of validity. Results are discussed in relation to the conceptual understanding of anxiety sensitivity, with specific emphasis on theoretical refinement of the construct.

Adolescent↗
PubMed2006

Strategies for managing symptoms of anxiety.

The purpose of this article is to summarize strategies for effectively managing the symptoms of anxiety. The distinction between the cognitive, physiological and behavioral components of fear and anxiety is explained and various treatment targets are outlined. Empirically-supported strategies that are effective in alleviating common symptoms of anxiety are reviewed. These include various forms of psychosocial intervention (i.e., cognitive and behavioral therapies), pharmacotherapy, in addition combined treatment approaches. Expert consensus guidelines, prognostic factors, patient preferences and accessibility issues are discussed with regard to treatment selection in addition to emerging challenges in the field and future research directions.

Anti-Anxiety Agents↗
PubMed2006

Health care utilization by United Nations peacekeeping veterans with co-occurring, self-reported, post-traumatic stress disorder and depression symptoms versus those without.

It remains to be determined whether patients with comorbid post-traumatic stress disorder (PTSD) and depression use more health care resources than do those without. United Nations peacekeeping veterans from Canada were divided into four groups, i.e., PTSD alone (n = 23), depression alone (n = 167), comorbid PTSD and depression (n = 119), and neither (n = 164), and compared with respect to total number of visits to any health care professional in the past year. Analysis of variance revealed that the groups significantly differed in total visits. Post hoc analyses indicated that veterans with co-occurring PTSD and depression symptoms had more visits than did those in the other groups and that veterans with PTSD symptoms alone and depression symptoms alone had more visits than did those with neither PTSD nor depression. Additional analyses revealed that veterans with co-occurring PTSD and depression symptoms made more visits to general practitioners, specialists, pharmacists, and mental health professionals than did the others. Future research directions and implications for treatment planning are discussed.

Adult↗
PubMed2006

Genetic and environmental origins of health anxiety: a twin study.

Excessive health anxiety - which is anxiety about one's health that is disproportionate to the person's medical status - is a common and often debilitating problem. Little is known about its etiology. The present study investigated the role of genetic and environmental factors using a classic twin study method. Results indicated that, after controlling for medical morbidity, environmental influences accounted for most of individual differences in health anxiety. These findings underscore the importance of psychosocial interventions, which have been shown to be among the most effective interventions for excessive health anxiety.

Journal Article↗
PubMed2005

The future of selective serotonin reuptake inhibitors (SSRIs) in psychiatric treatment.

Selective serotonin reuptake inhibitors (SSRIs) are widely prescribed and widely regarded as a first-line treatment for depression. Yet, a growing body of evidence indicates that these agents are only moderately more effective than placebo in treating major depressive disorder. In recent years, it has been debated whether SSRIs offer any clinically meaningful advantage over placebos. As part of this debate, it has been argued that these agents are first-line treatments for some forms of depression but not necessarily for others. The present paper examines two hypotheses that are central to these issues. The first hypothesis is that SSRIs are more effective than placebo for some types of depression but not for others. The second is that SSRIs are more effective than psychotherapies for some types of depression than others. A review of the empirical literature reveals three main classifications of depression that are relevant to the first hypothesis: (a) more vs. less severe depression, (b) melancholic vs. non-melancholic depression, and (c) depression defined according to associated genetic factors (particularly the long vs. short allele of the serotonin transporter gene promoter). There is no strong or consistent support for (a) or (b). There is, however, emerging and consistent evidence for (c), and so the first hypothesis is tentatively supported, but only for (c). Most of the empirical evidence does not support the second hypothesis. Psychotherapies (cognitive-behavioral and interpersonal therapies) and SSRIs generally have equivalent efficacy, regardless of the severity of depression. The research literature also suggests a third hypothesis that remains to be evaluated: that SSRIs are more effective for treating anxiety disorders (and possibly other disorders) than they are for treating depression. If that hypothesis is supported by subsequent research, then the future of SSRIs may lie largely in the treatment of anxiety disorders, and in the management of particular subtypes of depression.

Depression↗
PubMed2005

Simple versus complex PTSD: a cluster analytic investigation.

A cluster analytic investigation was conducted on measures of PTSD associated features (e.g., personality pathology, dissociative tendencies) to investigate whether empirically-defined clusters correspond to Herman's [1992, Complex PTSD: a syndrome in survivors of prolonged and repeated trauma. Journal of Traumatic Stress, 5, 377-391; 1997, Trauma and recovery (Rev. ed.). New York: Basic Books] distinction between simple and complex PTSD. Results from a sample of 60 PTSD patients were broadly consistent with this distinction, although some inconsistencies were observed. Treatment outcome generally did not differ between the two clusters. Implications for classifying and treating PTSD are discussed.

Adult↗
PubMed2005

Do dysfunctional beliefs play a role in all types of obsessive-compulsive disorder?

Some but not all models of obsessive-compulsive disorder (OCD) emphasize the role of dysfunctional beliefs in the etiology and maintenance of this disorder. Clinical observations suggest that some OCD patients have prominent dysfunctional beliefs associated with their obsessions and compulsions, while other patients do not show this pattern. It is possible that dysfunctional beliefs play a role in only a subgroup of cases of OCD and, by extension, that different models might apply to different subtypes of the disorder. To examine this issue, patients with OCD (N = 244) completed measures of dysfunctional OC-related beliefs, along with measures of OC symptoms and demographics. These measures were also completed by three comparison groups; anxious (N = 103), student (N = 284), and community (N = 86) controls. Cluster analysis revealed two OCD clusters: low versus high scores on beliefs (OC-low, OC-high). Belief scores for OC-low were in the range of scores for the comparison groups, which were all significantly lower than those of OC-high. Thus, a cluster of OCD patients was identified who did not have elevated scores on measures of dysfunctional beliefs. OC-low and OC-high did not differ on some OC measures (contamination, checking, grooming), but OC-high had higher scores on measures of harming obsessions. These results are consistent with the view that dysfunctional beliefs may play a role in only some types of OCD.

Adult↗
PubMed2005

Is obsessive-compulsive disorder a disturbance of security motivation? Comment on Szechtman and Woody (2004).

H. Szechtman and E. Woody (2004) proposed that obsessive-compulsive disorder (OCD) is caused by a malfunctioning brain security motivation system. In the current article, the authors' review of the model suggests that it is limited in the following ways: (a) It is built on a selective review of the empirical literature, (b) it offers no explanation for many important OCD phenomena, (c) it fails to distinguish OCD from generalized anxiety disorder, (d) some of the model's predictions are ambiguous or unfalsifiable, and (e) other predictions are refuted by previously published research. Models proposing that OCD is caused by a single dysfunctional mechanism, such as the security motivation model, have difficulty explaining the complexity and heterogeneity of OCD.

Animals↗
PubMed2005

Interoceptive exposure therapy combined with trauma-related exposure therapy for post-traumatic stress disorder: a case report.

Trauma-related exposure therapy is a useful but not universally effective treatment for post-traumatic stress disorder. Anxiety sensitivity may play an important role in this disorder, as it does in panic disorder. Studies have shown that interoceptive exposure therapy reduces anxiety sensitivity in panic disorder. The present case study was a preliminary investigation of the merits of including interoceptive exposure therapy in the treatment of post-traumatic stress disorder, in order to improve treatment outcome for a patient who had no history of panic disorder or panic attacks. Interoceptive exposure therapy (4 sessions) was one component of treatment, combined with trauma-related exposure therapy (4 sessions of imaginal exposure followed by 4 sessions of in vivo exposure). Treatment outcome was assessed with the Clinician-Administered Post-traumatic Stress Disorder Scale, a self-report measure of post-traumatic stress disorder symptoms, and measures of symptoms and cognitions commonly associated with post-traumatic stress disorder. Scores on all outcome measures decreased over the course of treatment, with gains maintained at 1- and 3-month follow-up. Symptoms of anxiety sensitivity and post-traumatic stress disorder decreased during interoceptive exposure therapy. The results indicate that interoceptive exposure therapy is a promising adjunctive intervention for post-traumatic stress disorder. Further research is needed into the merits of combining interoceptive exposure therapy and trauma-related exposure therapy as a means of boosting treatment efficacy.

Accidents, Traffic↗
PubMed2005

Hierarchical structure of dysfunctional beliefs in obsessive-compulsive disorder.

The Obsessive Beliefs Questionnaire was developed as a comprehensive measure of dysfunctional beliefs, which cognitive models consider to be etiologically related to obsessive-compulsive disorder. Obsessive Beliefs Questionnaire subscales tend to be highly correlated, which raises the question of whether obsessive-compulsive-related beliefs are hierarchically structured, consisting of lower-order factors loading on 1 or more higher-order factors. To investigate the nature and relative importance of these factors, a hierarchical factor analysis was conducted (n = 202 obsessive-compulsive disorder patients), using a Schmid-Leiman transformation. Results indicated a higher-order (general factor) and 3 lower-order factors: (i) responsibility and overestimation of threat, (ii) perfectionism and intolerance of uncertainty and (iii) importance and control of thoughts. The high-order factor accounted for more variance in Obsessive Beliefs Questionnaire scores (22%) than did the lower-order factors (6-7%), thereby underscoring the importance of the higher-order factor. Despite the importance of the higher-order factor, the lower-order factors significantly predicted unique variance in measures of obsessive-compulsive symptoms, including severity ratings of compulsions. These finding suggest that cognitive models of obsessive-compulsive disorder should take into consideration the hierarchic structure of obsessive-compulsive-related beliefs.

Adult↗