Search PubMed⌕ Search

Biomedical subjects

J R Davidson

Publications and source records attributed to J R Davidson.

At least 19 recordsLinked to original sources
PubMed2005

Acquisition of quality gamma-ray spectra with HPGe spectrometers.

We propose practices to optimize the quality of acquired gamma-ray spectra at a radioanalytical laboratory and to assist in the identification of extraneous spectral peaks including those from limitations in the physical setup, electronics, and counting conditions. This paper offers visible comparisons of high-quality spectra with those of inferior quality. We demonstrate the impacts on gamma-ray spectra taken with germanium (HPGe) detectors due to detector size, shape and energy resolution, background radiation, high-energy beta- or beta+ decay in the sample, beta(-)-, beta(+)- and gamma-ray backscatter, pole-zero cancellation, pulse pileup, coincidence summing, and unwanted sources of radiation.

Journal Article↗
PubMed2001

Multicenter, double-blind comparison of sertraline and placebo in the treatment of posttraumatic stress disorder.

BACKGROUND: Posttraumatic stress disorder (PTSD) is a common illness associated with significant disability. Few large, placebo-controlled trials have been reported. METHODS: Outpatients with a DSM-III-R diagnosis of moderate-to-severe PTSD were randomized to 12 weeks of double-blind treatment with either sertraline (N = 100) in flexible daily doses in the range of 50 to 200 mg or placebo (N = 108). Primary outcome measures consisted of the Clinician-Administered PTSD Scale (CAPS-2) total severity score, the patient-rated Impact of Event Scale (IES), and the Clinical Global Impression-Severity (CGI-S) and -Improvement (CGI-I) ratings. RESULTS: Mixed-effects analyses found significantly steeper improvement slopes for sertraline compared with placebo on the CAPS-2 (t = 2.96, P =.003), the IES (t = 2.26, P =.02), the CGI-I score (t = 3.62, P<.001), and the CGI-S score (t = 4.40, P<.001). An intent-to-treat end-point analysis found a 60% responder rate for sertraline and a 38% responder rate for placebo (chi(2)(1) = 8.48, P =.004). Sertraline treatment was well tolerated, with a 9% discontinuation rate because of adverse events, compared with 5% for placebo. Adverse events that were significantly more common in subjects given sertraline compared with placebo consisted of insomnia (35% vs 22%), diarrhea (28% vs 11%), nausea (23% vs 11%), fatigue (13% vs 5%), and decreased appetite (12% vs 1%). CONCLUSION: The results of the current study suggest that sertraline is a safe, well-tolerated, and significantly effective treatment for PTSD.

Adult↗
PubMed2001

Clinician-administered PTSD scale: a review of the first ten years of research.

The Clinician-Administered PTSD Scale (CAPS) is a structured interview for assessing posttraumatic stress disorder (PTSD) diagnostic status and symptom severity. In the 10 years since it was developed, the CAPS has become a standard criterion measure in the field of traumatic stress and has now been used in more than 200 studies. In this paper, we first trace the history of the CAPS and provide an update on recent developments. Then we review the empirical literature, summarizing and evaluating the findings regarding the psychometric properties of the CAPS. The research evidence indicates that the CAPS has excellent reliability, yielding consistent scores across items, raters, and testing occasions. There is also strong evidence of validity: The CAPS has excellent convergent and discriminant validity, diagnostic utility, and sensitivity to clinical change. Finally, we address several concerns about the CAPS and offer recommendations for optimizing the CAPS for various clinical research applications.

Case-Control Studies↗
PubMed2001

Mini-SPIN: A brief screening assessment for generalized social anxiety disorder.

The objectives of this study are to develop a brief self-rated screening instrument for generalized social anxiety disorder (GSAD) and to test the efficiency of the instrument. The Social Phobia Inventory (SPIN), a 17-item self-administered scale for GSAD, was given to 263 individuals with GSAD and controls. A subset of three items yielding high sensitivity and specificity for the diagnosis of GSAD was identified. This abbreviated version of the SPIN (Mini-SPIN) was administered to a group of managed care patients in conjunction with an epidemiological study of GSAD. Patients (n = 7,165) were sent a questionnaire comprising the Mini-SPIN and a brief depression screener. Respondents screening positive for GSAD on the Mini-SPIN (n = 344) were interviewed using the social phobia module of the Structured Clinical Interview for DSM-IV (SCID) to verify the diagnosis. A random sample of those who screened negative for GSAD on the Mini-SPIN were administered a similar interview to identify two control groups without GSAD for comparison (n = 673). With this information, the sensitivity, specificity, and positive and negative predictive values for the Mini-SPIN were determined (weighted for sampling). Using a cutoff score of 6 or greater, the Mini-SPIN demonstrated a sensitivity of 88.7%, specificity of 90.0%, positive predictive value of 52.5%, and negative predictive value of 98.5%. The scale possessed 90% accuracy (efficiency) in diagnosing the presence or absence of GSAD in a managed care population. The Mini-SPIN demonstrates good efficiency, supporting its utility as a screening tool for generalized social anxiety disorder.

Adult↗
PubMed2001

Paroxetine for social anxiety and alcohol use in dual-diagnosed patients.

The objective of this study was to compare the efficacy and tolerability of paroxetine to matched placebo in adults with co-occurring social anxiety disorder and alcohol use disorder. Outcome measures included standardized indices of social anxiety and alcohol use. Fifteen individuals meeting DSM-IV criteria for both social anxiety disorder and alcohol use disorder were randomized to treatment. Paroxetine (n = 6) or placebo (n = 9) was given in a double-blind format for 8 weeks using a flexible dosing schedule. Dosing began at 20 mg/d and increased to a target dose of 60 mg/d. There was a significant effect of treatment group on social anxiety symptoms, where patients treated with paroxetine improved more than those treated with placebo on both the Clinical Global Index (CGI) and the Liebowitz Social Anxiety Scale (Ps < or = 0.05). On alcohol use, there was not a significant effect of treatment on quantity/frequency measures of drinking, but there was for the CGI ratings (50% paroxetine patients versus 11% placebo patients were improvers on drinking, P < or = 0.05). This pilot study suggests that paroxetine is an effective treatment for social anxiety disorder in individuals with comorbid alcohol problems, and positive treatment effects can be seen in as little as 8 weeks. Further study is warranted to investigate its utility in helping affected individuals reduce alcohol use.

Adolescent↗
PubMed2001

Generalized anxiety disorder. An important clinical concern.

GAD is common, often follows a chronic course, and usually is associated with extensive psychiatric and medical comorbidity. This disorder often presents in a primary care setting, commonly with somatic symptoms; it is important for primary care physicians to be aware of its existence, forms of presentation, and different treatments. GAD appears to be twice as common in women than men. There is some evidence that the neurobiologic basis of GAD may involve abnormalities in neurochemical, neuroendocrine, neurophysiologic, and neuroanatomic factors. Research on psychosocial treatment of GAD has favored the combination of cognitive therapy and relaxation techniques or anxiety management training. It also appears that relapse rates after termination of cognitive-behavioral therapy are low. Taking into consideration that GAD generally is chronic and associated frequently with depressive symptoms, the ideal pharmacotherapy may be a drug that can treat these comorbid disorders adequately. New antidepressants, especially those with action in the serotonin system and possibly noradrenergic, may be the appropriate option: They not only treat anxiety, but also treat or prevent the development of comorbid depression; they should be effective ideally during prolonged periods without risks related to addiction or withdrawal, such as may happen with benzodiazepines and some antidepressants. The role of newly emerging drugs, such as some anticonvulsants, in GAD needs to be defined more clearly. More research is warranted to address issues such as (1) whether pharmacotherapy is as effective, less effective, or more effective than cognitive-behavioral therapy; (2) whether antidepressants improve the rate of wellness or remission; and (3) whether prolonged antidepressant therapy for GAD protects against later emergent depression.

Anti-Anxiety Agents↗
PubMed2001

Symptomatic and functional assessment of social anxiety disorder in adults.

There are several old and new tools for assessment of generalized SAD but few for nongeneralized SAD. Scales are available in both self-rated and interviewer-rated formats. Self-rated scales vary in appearance in length and specificity for SAD and psychometric properties. The best-studied self-rated scales are the FQ, FNE, SAAD, SPAI, and SPIN. The FQ is an early scale, with a subscale of social phobia with reasonable psychometric properties and has withstood the test of time. The FNE and SAAD are based on cognitive models of SAD but lack assessment of physiologic arousal symptoms--an important symptom cluster of SAD. The SPIN is a relatively new scale and shows potential especially with its three-item screener for generalized SAD. The two interviewer-rated scales, the LSAS and BSPS, are both widely used and demonstrate sound psychometric properties. Either one can be regarded as a satisfactory scale in the assessment of symptom severity and treatment response. The BSPS also measures several physical symptoms common in SAD. There are fewer validated tools available for nongeneralized SAD. It is a prevalent condition that may account for 25% or more of patients with SAD. More research is required on the epidemiology, recognition, assessment, and treatment of nongeneralized SAD. Education of patients and clinicians, and the use of improved and briefer tools in these settings, may help SAD patients to obtain appropriate help and improve their functioning and productivity. Few tools are available that can reliably assess disability due to SAD, and more research in this area is important and required.

Adult↗
PubMed2001

Predictors of treatment response in patients with posttraumatic stress disorder.

1. This study examines the relation between baseline clinical characteristics in patients with posttraumatic stress disorder (PTSD) and response to treatment with a reversible monoamine oxidase A inhibitor (RIMA), brofaromine. 2. Data from two comparable, double-blind, placebo-controlled studies of brofaromine in patients with PTSD were combined. Bivariate analyses of variables of interest and outcome were performed. 3. Treatment response was significantly associated with lower baseline scores on the full scale Clinician-Administered PTSD Scale (CAPS) and on CAPS subscales B (re-experiencing) and C (avoidance/numbing), as well as to drug treatment with brofaromine. Placebo response was related to a history of past sexual trauma. 4. Brofaromine may have therapeutic benefit in treating PTSD, with lower baseline levels of reexperiencing and avoidance/numbing and overall less severe PTSD most predictive of outcome.

Adult↗
PubMed2001

Adverse-effect profile of kava.

The use of alternative therapies has increased substantially over the last decade, particularly for more chronic conditions such as anxiety. Among the most widely used treatments are medicinal herbs, or phytomedicines, such as kava (Piper methysticum), which has demonstrated anxiolytic activity in both animal models and clinical samples. Kava has several advantages over conventional pharmacologic treatments for anxiety--in clinical settings it has been associated with better tolerability and lack of physiologic dependence and withdrawal. However, phytomedicines are not rigorously regulated in the United States and systematically collected safety data are very limited. These issues are a leading concern regarding the safety of medicinal herbs such as kava. In this report, the safety profile for kava is provided, including findings from a study of its use in generalized anxiety disorder. Safety parameters assessed include occurrence of adverse events, withdrawal symptoms, effect on heart rate, blood pressure, laboratory assessments, and sexual function. No differences were found between kava and placebo on any of the parameters evaluated. The data support the safety of kava in treating anxiety at 280 mg kava lactones/day for 4 weeks.

Journal Article↗
PubMed2001

The self-assessment of resilience and anxiety: psychometric properties.

This report describes the psychometric properties of the Self-Assessment of Resilience and Anxiety (SARA) scale within the context of a study of kava for generalized anxiety. This eight-item, patient-rated scale includes questions designed to measure calmness, mental clarity, confidence, physical well being, sociability, and resilience. The SARA scale was administered during a clinical trial of kava versus placebo in 38 subjects diagnosed with generalized anxiety disorder (GAD). Validation of the SARA scale was assessed against the Hamilton Rating Scale for Anxiety, Hospital Anxiety and Depression Scale, Penn State Worry Questionnaire, Sheehan Disability Scale, Arizona Sexual Experience scale, and Clinical Global Impression of Illness Improvement scale. Good test-retest reliability, internal consistency, convergent validity, and sensitivity to treatment were identified, and factor analyses revealed a three-factor internal structure. The SARA scale was responsive to symptom change over time and correlated with comparable GAD symptom measures. The SARA scale demonstrates solid psychometric properties and may serve as a reliable and valid measure in the use of kava or related medicinal herbs.

Journal Article↗
PubMed2001

Social anxiety disorder in review: two decades of progress.

Social anxiety disorder (SAD) is among the most common of all psychiatric disorders. It presents with a lifetime prevalence rate of up to 16% in the general population and, like other anxiety disorders, is more frequent in women. Patients with SAD suffer from considerable psychiatric comorbidity that is often preceded by social anxiety. Social anxiety affects people early in life and provokes a great deal of impairment and cost, much being related to the under-recognition and/or under-treatment of this disorder, which occurs frequently with GPs and others specialists. There is a clear need among GPs for training and awareness about the existence of this disorder, its assessment, differential diagnosis and available treatments. In this paper we review the development of the concept of SAD and its epidemiology, and discuss the available information regarding cost and how SAD presents in primary-care settings. Potential aetiologies and studies concerning possible neurobiological mechanisms are also reviewed. Pharmacological and psychosocial treatments for SAD are examined and effect sizes calculated for placebo-controlled pharmacological studies of five medication categories.

Humans↗
PubMed2001

Olanzapine in the treatment of post-traumatic stress disorder: a pilot study.

Because the atypical antipsychotic olanzapine may be efficacious in treating post-traumatic stress disorder (PTSD) symptoms, we conducted a 10-week, double-blind, placebo-controlled evaluation in which 15 patients were randomized 2:1 to either olanzapine or placebo. The initial dosage was 5 mg/day and was titrated to a maximum of 20 mg/day. Eleven patients completed the study. Patients in both groups showed improvement in PTSD symptoms, but no between-group differences in treatment response were observed and a high placebo response rate was found. Both treatments were tolerated well, although the olanzapine treatment group had more weight gain. Olanzapine fared no better than placebo in this preliminary study in the treatment of PTSD. The lack of difference between olanzapine and placebo may in part be due to olanzapine's not being effective in PTSD or, alternatively, a small sample size, a high placebo response in certain forms of PTSD and the chronicity of PTSD symptoms in some patients.

Adolescent↗
PubMed2001

SPRINT: a brief global assessment of post-traumatic stress disorder.

This report describes the reliability, validity, treatment sensitivity, diagnostic performance and normative values for the Short Post-Traumatic Stress Disorder (PTSD) Rating Interview (SPRINT), a brief, global assessment for PTSD. The SPRINT was administered to subjects participating in a clinical trial of PTSD and in a population survey assessing PTSD prevalence. The 8-item SPRINT includes questions assessing the core symptoms of PTSD, as well as related aspects of somatic malaise, stress vulnerability and functional impairment. Validity was assessed against the MINI structured interview, the Davidson Trauma Scale, Treatment Outcome for PTSD Scale, Connor-Davidson Resilience Scale, Sheehan Stress Vulnerability Scale, Sheehan Disability Scale and Clinical Global Impressions of Severity and Improvement Scales. Good test-retest reliability, internal consistency, convergent and divergent validity were obtained. The SPRINT was responsive to symptom change over time and correlated with comparable PTSD symptom measures. In victims of trauma, a score of 14-17 was associated with 96% diagnostic accuracy, whereas in those with PTSD, highest efficiency corresponded to a range of 11-13. The SPRINT demonstrates solid psychometric properties and can serve as a reliable, valid and homogeneous measure of PTSD illness severity and of global improvement.

Adult↗