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Biomedical subjects

R Swinson

Publications and source records attributed to R Swinson.

15 recordsLinked to original sources
PubMed2000

Increased left posterior parietal-temporal cortex activation after D-fenfluramine in women with panic disorder.

It is unclear whether the functional changes found in panic disorder reflect disturbed physiology of particular neurotransmitters. One method of investigating altered neurotransmission is to assess regional brain activations in response to agonist challenges. D-Fenfluramine is a medication that induces neuronal release of serotonin. Using ¿15OH(2)O and positron emission tomography (PET), measurements of regional cerebral blood flow (rCBF) were done at t=-20, -5, +20 and +35 relative to the IV D-fenfluramine injection (t=0) in nine panic-disordered and 18 healthy subjects. Subjects were otherwise healthy, right-handed, non-smoking and not taking psychotropic medication. ¿15OH(2)O PET scans were assessed with Statistical Parametric Mapping using individual global cerebral blood flow as a covariate. Comparisons of the (baseline) first two scans between healthy and panic-disordered subjects showed a decreased rCBF in the left posterior parietal-superior temporal cortex in the patient group. Fenfluramine-induced increases as defined by the last two scans minus the first two scans were compared between groups and a significantly greater increase in the same left posterior parietal-superior temporal region was found in panic-disordered subjects. Consistent with this finding, differences between the last two scans (post-fenfluramine) of the healthy and panic-disordered subjects showed an increased rCBF in the left superior temporal cortex in panic-disordered subjects. Functional pathology in the left parietal-superior temporal cortex in panic disorder may be related to abnormal modulation by serotonin.

Adolescent↗
PubMed2000

Prevention of relapse in generalized social phobia: results of a 24-week study in responders to 20 weeks of sertraline treatment.

The aim of this study was to evaluate the efficacy, tolerability, and effects on quality of life of sertraline, a selective serotonin reuptake inhibitor, in the prevention of relapse of generalized social phobia. Fifty adult outpatients with generalized social phobia who were rated much or very much improved on the Clinical Global Impression Scale of Improvement (CGI-I) after 20 weeks of sertraline treatment (50-200 mg/day) were randomly assigned in a one-to-one ratio to either continue double-blind treatment with sertraline or immediately switch to placebo for another 24 weeks. The initial 20-week study was placebo-controlled, and 15 responders to placebo also continued to receive double-blind placebo treatment in the continuation study. Eighty-eight percent of patients in the sertraline-continuation group and only 40% of patients in the placebo-switch and placebo-responder groups completed the study. In intent-to-treat endpoint analyses, 1 (4%) of 25 patients in the sertraline-continuation group and 9 (36%) of 25 patients in the placebo-switch group had relapsed at study endpoint (chi2 = 8.0, Fisher exact test, p = 0.01). The relative risk (hazards ratio) for relapse associated with placebo-switch relative to sertraline-continuation treatment was 10.2 (95% confidence interval, 1.3-80.7). Mean CGI-Severity, Marks Fear Questionnaire (MFQ) Social Phobia subscale, and Duke Brief Social Phobia Scale (BSPS) total scores were reduced by 0.07, 0.34, and 1.86 in the Sertraline-Continuation group and increased by 0.88, 4.09, and 5.99 in the Placebo-Switch group (all F > 5.3, p < 0.03), respectively. CGI-Severity, MFQ Social Phobia subscale, and BSPS scores also increased in the Placebo-Responder group. Discontinuations because of lack of efficacy were 4% in the sertraline-continuation group, 28% in the placebo-switch group (chi2 = 5.36, Fisher exact test, p = 0.049), relative to sertraline, and 27% in the placebo-responder group. Sertraline was effective in preventing relapse of generalized social phobia. Future research should assess whether improvements may be maintained or further increased by longer periods of treatment or through the addition of cognitive-behavioral techniques.

Adult↗
PubMed1997

Double-blindness procedures, rater blindness, and ratings of outcome. Observations from a controlled trial.

BACKGROUND: We determined whether blindness in a double-blind randomized controlled trial of alprazolam and exposure therapies in patients with panic disorder and agoraphobia was maintained in assessors and patients, what were the factors related to "unblinding," and whether unblinding was associated with clinical outcome. METHOD: In 129 patients with panic disorder and agoraphobia who were randomized to alprazolam-exposure, placebo-exposure, alprazolam-relaxation, or placebo-relaxation conditions, blindness was tested at the end of treatment by the independent assessors' and patients' classification of the treatment condition. RESULTS: Assessors' classifications were correct in 82% of the alprazolam group and 78% of the placebo group; corresponding figures for patients' classifications were 73% and 70%, respectively. Factors associated with unblinding included drug side effects but not assessors' ratings of treatment outcome. CONCLUSION: Judgment of the validity of the outcome of a randomized controlled trial is easier if the report notes not only the use of a double-blindness procedure but also details how blind the raters remained and how any unblinding affected their ratings of clinical outcome.

Agoraphobia↗
PubMed1995

Diagnosing comorbidity in substance abusers: a comparison of the test-retest reliability of two interviews.

This study examines the test-retest reliability of two interview schedules (computer- and clinician-administered) in diagnosing lifetime comorbidity in treated substance abusers. The Computerized Diagnostic Interview Schedule (C-DIS) and the Structured Clinical Interview for DSM-III-R (SCID) were both administered to 173 substance abusers after random assignment to one of two groups. Within 1 to 2 weeks, subjects in the first group repeated the C-DIS and subjects in the second group were reinterviewed by a different clinician, blind to the results of the initial SCID. Both instruments showed good to excellent reliability for DSM-III-R psychoactive substance use disorders with kappas ranging from .50 to .89 for individual disorders. However, the reliability of comorbid other mental disorders was substantially poorer on both instruments, particularly the SCID. C-DIS kappas ranged from -.05 for generalized anxiety to .70 for simple phobia. SCID kappas ranged from .31 for panic disorder to .83 for antisocial personality disorder. Anxiety disorders as a category, some phobic disorders, and antisocial personality disorder showed acceptable levels of test-retest reliability on both instruments. There was a trend for borderline or threshold cases to account for some of the disagreement on the C-DIS. Differences of opinion between clinicians on organicity accounted for some of the disagreements on panic disorder and major depression. The C-DIS, unlike the SCID, tended to diagnose more disorders at initial interview, perhaps a result of its tedious probe structure. Neither instrument should be administered only once to provide a reliable lifetime diagnostic profile of comorbidity in substance abusers.

Adolescent↗
PubMed1994

Diagnosing comorbidity in substance abusers. Computer assessment and clinical validation.

This study compares DSM-III-R lifetime diagnoses assigned to a sample of substance abusers in treatment made by the Computerized Diagnostic Interview Schedule (C-DIS) with those made by clinicians on the basis of the Structured Clinical Interview for DSM-III-R (SCID) and patient chart information. A sample of 173 subjects were interviewed with the C-DIS and then by a clinician using the SCID. A second SCID was administered by a different clinician to 80 of the subjects 1 to 2 weeks later and consensus diagnoses were then made using all available information. With the exception of antisocial personality disorder and most psychoactive substance use disorders, the initial C-DIS showed poor diagnostic agreement with the initial SCID. As a potential screening instrument, the C-DIS did identify 30 of the 32 subjects with a consensus axis I (nondrug) disorder, but diagnosed twice as many positives as were confirmed by the consensus diagnoses. A negative C-DIS for comorbid disorders was confirmed in 9 out of 10 cases by clinicians.

Adolescent↗
PubMed1994

Safety and side-effects of alprazolam. Controlled study in agoraphobia with panic disorder.

BACKGROUND: The widespread use of benzodiazepines has led to increasing recognition of their unwanted effects. The efficacy of alprazolam and placebo in panic disorder with agoraphobia, and the side-effect and adverse effect profiles of both drug groups were measured. METHOD: In London and Toronto 154 patients who met DSM-III criteria for panic disorder with agoraphobia were randomised to alprazolam or placebo. Subjects in each drug group also received either exposure or relaxation. Treatment was from weeks 0 to 8 and was then tapered from weeks 8 to 16. RESULTS: Mean alprazolam dose was 5 mg daily. Compared with placebo subjects, alprazolam patients developed more adverse reactions (21% v. 0%) of depression, enuresis, disinhibition and aggression; and more side-effects, particularly sedation, irritability, impaired memory, weight loss and ataxia. Side-effects tended to diminish during treatment but remained significant at week 8. Despite this, the drop-out rate was low. CONCLUSIONS: Alprazolam caused side-effects and adverse effects during treatment but many patients were willing to accept these.

Adult↗
PubMed1989

The effects of fenfluramine (hydrochloride) on the behaviors of fifteen autistic children.

Fifteen autistic individuals were involved in an investigation using fenfluramine and placebo in a double-blind crossover design. Subjects were assessed using IQ tests, the Real Life Rating Scale (RLRS), the Adaptive Behavior Scale-School Edition (ABS-SE), and videotaped play data on 8 of 12 visits, including 2 follow-up visits. Serotonin level in platelet-poor plasma was assessed on all 12 visits. Serotonin levels decreased with the administration of fenfluramine, and increased with the reinstatement of placebo. Statistical tests revealed no significant differences on the IQ scores, the RLRS, or the ABS-SE for the drug versus the placebo conditions. Videotaped data favored the subjects while on placebo. Group and individual data were analyzed over time and indicated no significant improvements due to the drug. The implications of this research make it difficult to recommend fenfluramine as a treatment for autism.

Activities of Daily Living↗
PubMed1989

Evaluation of buspirone as an antianxiety agent: buspirone and diazepam versus placebo.

Buspirone has previously been demonstrated to be efficacious in the treatment of anxiety. This four-week double-blind parallel study compared buspirone to diazepam and placebo in the treatment of 119 outpatients diagnosed as having generalized anxiety disorder. After a seven-day placebo washout period, eligible patients were randomized to one of three treatment groups. Buspirone (5 mg) and diazepam (5 mg) were administered BID and individually titrated to an optimal therapeutic dose by the end of week two. Buspirone and diazepam were equally effective in reducing Hamilton Anxiety (HAM-A) total and psychic factor scores from baseline values. Buspirone alone was significantly better than placebo in reducing the HAM-A somatic factor score. Sixty-seven percent of both active treatment groups who were classified as "ill" on the baseline global psychopathology rating scale achieved a "not ill" status by study end. There were no significant differences between treatment groups at endpoint on the 56-item Symptom Checklist self-rating scale. Buspirone was demonstrated to be as effective as diazepam in relieving anxiety in this outpatient sample.

Adult↗
PubMed1987

Past and current thyroid function in subjects with panic disorder.

Disturbances in thyroid function can result in symptoms similar to those occurring in patients with anxiety disorders, especially panic disorder. An association between thyroid illness and panic and phobic disorders has been suggested, but few studies have directly investigated this issue. To assess this possible relationship, the authors measured indices of thyroid function in 165 subjects who had a current DSM-III diagnosis of panic disorder, either with or without phobic avoidance. These subjects reported a higher prevalence of thyroid illness by history compared with the prevalence of thyroid illness in the general population; however, less than 1% of all subjects had current thyroid dysfunction. The presence of a major depressive episode (MDE) was unrelated to current thyroid function, although subjects with MDE reported a higher prevalence of thyroid disease by history. Indices of thyroid function were not correlated with the severity of panic attacks or phobias.

Adult↗