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Biomedical subjects

D Kaloupek

Publications and source records attributed to D Kaloupek.

7 recordsLinked to original sources
PubMed2001

Empirically supported ethical research practice: the costs and benefits of research from the participants' view.

Researchers and institutional review boards are routinely called upon to evaluate the cost-benefit status of proposed research protocols that involve human participants. Often these assessments are based on subjective judgments in the absence of empirical data. This reliance on subjective judgments is of particular concern for studies involving clinical samples where unfounded assumptions may adversely affect research progress or clinical outcomes. The Reactions to Research Participation Questionnaire (RRPQ) was designed to address this shortcoming and to help promote ethical decision making about research practice. The present study describes development of the RRPQ and presents a series of exploratory and confirmatory analyses investigating its structure. Based on these findings, a revised version of the instrument and suggestions for future research are presented. This approach provides a foundation for scientifically informed protection of human subjects.

Behavioral Research↗
PubMed2000

Stimulus novelty differentially affects attentional allocation in PTSD.

BACKGROUND: This study investigated attentional allocation in 39 Vietnam combat veterans, 25 with and 14 without posttraumatic stress disorder, assessing P300 amplitudes and latencies during both three-tone and novelty "oddball" tasks. METHODS: The three-tone oddball task consisted of three stimuli: frequent tones (85%), rare target tones (7.5%), and rare distractor tones (7.5%). The novelty oddball task was identical to the three-tone task except that the rare distractor tones were replaced with nonrepeating novel sounds (7.5%). RESULTS: Combat veterans with posttraumatic stress disorder showed significant P300 amplitude enhancements at frontal sites in response to distracting stimuli during the novelty but not during the three-tone oddball tasks. There were no amplitude differences in target tones during either task. CONCLUSIONS: The data suggest that combat veterans with posttraumatic stress disorder demonstrate P300 responses consistent with a heightened orientation response to novel, distracting stimuli. This finding is consistent both with the clinical presentation of the disorder and with theoretical notions that individuals with posttraumatic stress disorder demonstrate information-processing biases towards vague or potentially threatening stimuli.

Anxiety↗
PubMed2000

Trauma-related psychophysiological reactivity in women exposed to war-zone stress.

Women are at particular risk for Posttraumatic Stress Disorder (PTSD), but surprisingly little is known about their objective manifestations of the disorder's hallmark symptoms. Although research suggests that people with PTSD exhibit physiological reactivity to the presentation of trauma-related cues, the majority of studies to date have focused on men. We assessed the physiological reactions of three groups of trauma-exposed female Vietnam veterans (those with current PTSD, lifetime PTSD, or no PTSD) to war-related stimuli. Responses of women with current PTSD differed significantly from those without PTSD on skin conductance and systolic blood pressure, and mean levels of reactivity for women with lifetime PTSD fell between the other two groups. Although symptom severity was correlated with physiologic reactivity overall, results suggested differential relationships at the symptom cluster level. Study results replicate earlier findings with men and extend knowledge of autonomic reactivity to an important group of female survivors.

Adult↗
PubMed2000

Emotional processing in posttraumatic stress disorder.

The emotional deficits associated with posttraumatic stress disorder (PTSD) are the least understood and the most understudied aspect of the syndrome. In this study, the connection was evaluated between trauma-context reactivity and subsequent emotional deficits in PTSD. Combat veterans with PTSD and well-adjusted veteran control participants were exposed to reminders of combat, after which their emotional behavior was assessed in response to a series of emotionally evocative images. Under the neutral condition, both groups exhibited emotional behavior modulated by stimulus valence. Partially consistent with the conceptual model described by B. Litz (1992), the PTSD group exhibited suppressed expressive-motor responses to positively valenced images, in comparison with the control group, only after being exposed to a trauma-related prime. Contrary to expectations, the PTSD group showed no augmentation of emotional response to negatively valenced cues after being exposed to trauma reminders. However, the PTSD group responded to all images, in both prime conditions, with higher heart rate reactivity, suggesting an automatic preparation for demand or threat in any uncertain emotional context. Possible causes and consequences of these results are discussed.

Arousal↗
PubMed1999

Neural correlates of exposure to traumatic pictures and sound in Vietnam combat veterans with and without posttraumatic stress disorder: a positron emission tomography study.

BACKGROUND: Patients with posttraumatic stress disorder (PTSD) show a reliable increase in PTSD symptoms and physiological reactivity following exposure to traumatic pictures and sounds. In this study neural correlates of exposure to traumatic pictures and sounds were measured in PTSD. METHODS: Positron emission tomography and H2[15O] were used to measure cerebral blood flow during exposure to combat-related and neutral pictures and sounds in Vietnam combat veterans with and without PTSD. RESULTS: Exposure to traumatic material in PTSD (but not non-PTSD) subjects resulted in a decrease in blood flow in medial prefrontal cortex (area 25), an area postulated to play a role in emotion through inhibition of amygdala responsiveness. Non-PTSD subjects activated anterior cingulate (area 24) to a greater degree than PTSD patients. There were also differences in cerebral blood flow response in areas involved in memory and visuospatial processing (and by extension response to threat), including posterior cingulate (area 23), precentral (motor) and inferior parietal cortex, and lingual gyrus. There was a pattern of increases in PTSD and decreases in non-PTSD subjects in these areas. CONCLUSIONS: The findings suggest that functional alternations in specific cortical and subcortical brain areas involved in memory, visuospatial processing, and emotion underlie the symptoms of patients with PTSD.

Analysis of Variance↗
PubMedDate not supplied

Posttraumatic stress disorder and the use of health services.

OBJECTIVE: Prior research has demonstrated increased use of medical services among persons with anxiety and depression. This investigation examined the possible association of posttraumatic stress disorder (PTSD) with the use of nonmental health services. METHOD: A case-comparison design enrolled 102 high users of health services and 54 low users who were assessed for PTSD diagnosis and severity of PTSD symptoms. Subjects were male veterans receiving services from the primary care clinics of the VA Boston Healthcare System during an 18-month period. Data were collected by interview by use of standardized instruments including the Clinician Administered PTSD Scale for DSM-IV, the Life Events Checklist, and the Beck Depression Inventory. Data analysis employed odds ratios, linear and logistic regression, and path analyses. RESULTS: High users of health care were almost twice as likely as low users (27.5% vs. 14.8%) to meet diagnostic criteria for current PTSD. The two groups differed significantly on both symptom frequency and intensity. Path analyses showed an indirect positive association between PTSD and health services use, with physician-diagnosed health conditions as a mediating variable. Auxiliary analysis demonstrated that the combined mental health burden of PTSD and depression symptoms also is positively associated with number of health conditions. CONCLUSIONS: The findings indicate that PTSD, alone and in combination with depression, has a direct negative relationship with physical health that, in turn, is associated with more frequent use of primary health care services. These results do not suggest that PTSD leads to inappropriate (eg, distress-motivated) use of services.

Adult↗