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Biomedical subjects

J R Davidson

Publications and source records attributed to J R Davidson.

At least 127 records · Page 7Linked to original sources
PubMed1994

Pharmacotherapy for post-traumatic stress disorder.

PTSD is a common disorder with high comorbidity and a tendency toward chronicity, which responds slowly to treatment and, in many patients, may not totally resolve even with long-term treatment. For most persons with PTSD, a combined approach to treatment is beneficial, at least in the acute stages of the illness. Pharmacotherapy is an important component of treatment during the acute stages of the illness and may be necessary on a long-term basis for many patients. Because the data from controlled trials of pharmacotherapy are limited, it is not possible to present a unified approach or develop a consensus that is well supported by research findings. What has emerged from the available data is that antidepressants, particularly those with serotoninergic properties, are helpful for core PTSD symptoms when given at higher dose levels for at least 5 to 8 weeks. The TCAs as a group appear to be effective in amelioration of the intrusive symptoms and of anxiety and depressive symptoms, while having little effect on avoidance symptoms. Initial data from studies of the SSRIs suggests that they may have greater efficacy than other drugs in the treatment of avoidance and numbing symptoms and may effect enough overall global improvement in PTSD symptoms that some patients will no longer meet the diagnostic criteria. The hyperarousal symptoms may respond somewhat to antidepressants, but should symptoms continue to be disabling, buspirone or benzodiazepines may be indicated. In choosing a benzodiazepine, those less likely to have distressing withdrawal symptoms, such as clonazepam and chlordiazepoxide, should be considered. Clonazepam, with its serotoninergic properties, may prove to be a particularly efficacious drug. For some patients, phenelzine may be a good choice because it has proven efficacy for the intrusive PTSD symptoms, for depressive symptoms, and for some symptoms of autonomic arousal, such as panic attacks. Other agents to be considered for alleviation of hyperarousal symptoms are lithium, anticonvulsants, and clonidine. In addressing the symptoms of poor impulse control, lithium, beta-blocking drugs, and carbamazepine may be helpful. Brief psychotic episodes should respond to a neuroleptic, although psychoticlike dissociative spells may be nonresponsive.

Arousal↗
PubMed1994

Adinazolam sustained-release treatment of panic disorder: a double-blind study.

Two hundred six outpatients with panic disorder and agoraphobia were randomly assigned to receive 4 weeks of treatment with placebo or sustained-release adinazolam under double-blind conditions. Eighty-eight percent of patients receiving drug and 85% of patients receiving placebo remained in the study at week 4. This report describes the "intent-to-treat" analysis of 202 patients who made at least one follow-up visit after randomization at baseline. On the basis of the Clinical Global Impressions-Improvement Scale, 69.7% of the adinazolam-treated patients were much or very much improved compared with 39.6% of the placebo-treated patients at week 4 or end-point (p = 0.0001). At week 4, panic attacks were completely blocked in 57.1% of adinazolam-treated patients and in 39.2% of the placebo-treated patients (p = 0.009). Adinazolam sustained-release treatment was statistically more effective than placebo treatment on measures of global improvement, number of panic attacks, SCL-90 phobia severity, main phobia severity, and anticipatory and general anxiety. No drug-placebo differences were found for overall self-rated phobia severity, unexpected or situational panic attacks, or for work, family, or social disability.

Adult↗
PubMed1994

Treatment of social phobia with benzodiazepines.

Although social phobia is a common and highly treatable anxiety disorder, the majority of social phobics do not receive treatment. Without intervention, it is unlikely that patients will attain significant relief from the symptoms and disability associated with the disease. The authors review the results of studies concerning the use of high-potency benzodiazepines in the treatment of social phobia. These studies, which include open trials as well as a double-blind, placebo-controlled evaluation of clonazepam, have demonstrated clinical efficacy and suggest a therapeutic role for this drug class in the treatment of social phobia. Developmental work with the Davidson Brief Social Phobia Scale is described, along with predictors of treatment outcome for clonazepam and placebo and relapse data upon discontinuation of both treatments. Finally, the authors discuss general issues concerning the relapse of patients upon drug discontinuation, the long-term use of benzodiazepines, and other important issues concerning the use of these agents for the treatment of social phobia.

Alprazolam↗
PubMed1993

Pyloric stenosis: the Christchurch experience.

OBJECT: Evaluation of the performance of a general paediatric unit in diagnosis and treatment of infantile hypertrophic pyloric stenosis, including morbidity and measurable outcomes in relationship to changing management. METHODS: Retrospective case note audit. RESULTS: In the 11 year period 1980-91, 103 infants underwent surgical correction of pyloric stenosis, after correction of metabolic disturbance. There was a predominance of males (82.5%), but the incidence of first born infants affected was no greater than the population birth order. While the clinical diagnosis was firm in the majority of infants, over 75% had at least one radiologic imaging procedure. On objective criteria, 80% of patients were less than 5% dehydrated, despite having electrolyte and acid-base derangement. The relatively high incidence of mucosal perforation (31.1%) did not lead to further morbidity. The incidence of postoperative vomiting (19.4%) was significantly less than in previously reported series. There were no deaths, one patient suffered longterm neurologic deficit following profound hypoglycaemia. A change in preoperative management to aggressive rehydration did not reduce morbidity, and was associated with an increased median postoperative stay. CONCLUSIONS: Pyloric stenosis remains a relatively common surgical problem of infancy. The cornerstone of diagnosis remains a clinical one; however there is a place for radiology. Operative repair is elective, following correction of metabolic derangement. In a general paediatric unit, long term sequelae of initial morbidity are rare.

Body Weight↗
PubMed1993

The epidemiology of social phobia: findings from the Duke Epidemiological Catchment Area Study.

Social phobia was studied in a North Carolina community, using DSM-III criteria. Two kinds of comparison were made: social phobia v. non-social phobia, and comorbid social phobia v. non-comorbid social phobia. Six-month and lifetime prevalence rates were 2.7 and 3.8% respectively. Social phobia had an early onset, lasted a long time and rarely recovered. Predictors of good outcome recovery in a logistic regression analysis were onset of phobia after age 11, absence of psychiatric comorbidity and greater education. The disorder was often missed in medical consultation. Increased rates of psychiatric comorbidity existed, especially for other anxiety disorders and for schizophrenia/schizophreniform disorder. There was increased risk of neurological disorder. Social phobia was also associated with an increased rate of suicide attempts, antisocial behaviour and impaired school performance during adolescence, impaired medical health, increased health-seeking behaviour, poor employment performance, reduced social interaction and impaired social support. Comorbidity accounted for some, but not all observed differences.

Adolescent↗
PubMed1993

Predicting response to amitriptyline in posttraumatic stress disorder.

OBJECTIVE: This study evaluated the relation between baseline clinical phenomena and response to amitriptyline in patients with posttraumatic stress disorder (PTSD). METHOD: Data were obtained from an 8-week placebo-controlled, double-blind study of combat veterans. Bivariate and multivariate statistics were used to evaluate the relations between the following variables and outcome: age, depression, anxiety, severity of PTSD symptoms, personality, psychiatric comorbidity, level of exposure to trauma, and individual symptoms of depression, anxiety, and traumatic stress. Outcome measures were scores on the Clinical Global Impression scale, Hamilton Rating Scale for Depression, Hamilton Rating Scale for Anxiety, and Impact of Event Scale. RESULTS: Drug response was related to lower baseline levels of depression, neuroticism, combat intensity, anxious mood, impaired concentration, somatic symptoms, feelings of guilt, and one intrusion and four avoidance symptoms of PTSD. CONCLUSIONS: The results demonstrate that response to amitriptyline is related to measures of depression, anxiety, PTSD, personality, and intensity of combat trauma. Similar relationships were not observed in the placebo group, suggesting a specific relationship to the drug.

Amitriptyline↗
PubMed1993

Treatment of social phobia with clonazepam and placebo.

Clonazepam and placebo were administered in a double-blind pilot study to 75 outpatients with social phobia. The mean maximum dose of clonazepam was 2.4 mg/day at endpoint (range, 0.5 to 3 mg). Treatment was continued for up to 10 weeks. The results of an intent-to-treat analysis indicated superior effects of clonazepam on most measures. Response rates for clonazepam and placebo were 78.3 and 20.0%. Drug effects were apparent on performance and generalized social anxiety, on fear and phobic avoidance, on interpersonal sensitivity, on fears of negative evaluation, and on disability measures. Significant differences were evident by week 1, 2, or 6, depending upon the rating scale used. Clonazepam was well tolerated in general, although unsteadiness and dizziness were more severe and persistent than was the case for placebo subjects.

Adult↗
PubMed1993

The role of nuclear magnetic resonance imaging in psychiatric research.

Magnetic resonance imaging (MRI) has become an important tool in the investigation of cerebral abnormalities associated with psychiatric illnesses. There are a number of benefits of investigating psychiatric illness with MRI, which is superior to computed tomography scanning. MRI has been used to study neurologic deficits seen in schizophrenia, affective disorders, dementia, and more recently, anxiety disorders. Magnetic resonance spectroscopy offers a new investigational technique that adds functional information to the structural changes seen with standard MRI scanning. This review highlights the current data in living human subjects that demonstrate structural changes in psychiatric disorders using MRI, including recent studies of the anxiety disorders.

Aged↗
PubMed1993

Magnetic resonance spectroscopy in social phobia: preliminary findings.

Proton localized magnetic resonance spectroscopy was studied in 20 social phobics and 20 age- and sex-matched controls. Stimulated Echo Acquisition Mode volume element localization was used with chemical shift imaging. Choline and creatine signal-to-noise ratios (SNRs) were significantly lower in social phobia than in controls in subcortical, thalamic, and caudate areas. In the social phobic group, N-acetylaspartate (NAA) SNR was significantly lower in cortical and subcortical regions, and ratios of NAA to other metabolites were lower in social phobia. Choline, creatine, and NAA SNRs were inversely correlated to total social phobia and fear symptoms, as measured by the Brief Social Phobia Scale, in the thalamic and noncortical gray areas. In a small number of patients who received clonazepam, posttreatment SNRs generally increased relative to baseline. Our results suggest a promising place for magnetic resonance spectroscopy in social phobia and also indicate potential pharmacodynamic uses of this technique.

Adult↗
PubMed1992

Cardiac arrest in Ontario: circumstances, community response, role of prehospital defibrillation and predictors of survival.

OBJECTIVES: To describe the patient characteristics, circumstances and community response in cases of out-of-hospital cardiac arrest; to evaluate the effect on survival of the introduction of prehospital defibrillation; and to identify factors that predict survival. DESIGN: Population-based before-and-after clinical trial. SETTING: Five Ontario communities: London, Sudbury, the Greater Niagara region, Kingston and Ottawa. PATIENTS: A consecutive sample of 1510 primary cardiac arrest patients who were transported to hospital by ambulance over 2 years. INTERVENTION: The use of defibrillators by ambulance attendants. MAIN OUTCOME MEASURES: Patient characteristics (sex and age), circumstances of arrest (place, whether arrest was witnessed and cardiac rhythm), citizen response (whether cardiopulmonary resuscitation [CPR] was started by a bystander, time to access to emergency medical services and time to initiation of CPR), emergency medical services response (ambulance response time, time to initiation of CPR and time to rhythm analysis with defibrillator) and survival rates. MAIN RESULTS: A total of 92.1% of the patients were 50 years of age or older, and 68.3% were men. Overall, 79.6% of the arrests occurred in the home. The average ambulance response time for witnessed cases was 7.8 minutes. The overall survival rate was 2.5%. The survival rates before and after defibrillators were introduced were similar, and the general functional outcome of the survivors did not differ significantly between the two phases. Factors predicting survival included patient's age, ambulance response time and whether CPR was started before the ambulance arrived. CONCLUSIONS: The survival rate was lower than expected. The availability of prehospital defibrillation did not affect survival. To improve survival rates after cardiac arrest ambulance response times must be reduced and the frequency of bystander-initiated CPR increased. Once these changes are in place a beneficial effect from advanced manoeuvres such as prehospital defibrillation may be seen.

Adult↗
PubMed1992

Social phobia: biological aspects and pharmacotherapy.

1. Social phobia is one of the anxiety disorders that until recently, had not been thoroughly investigated. 2. Social phobia is a relatively common anxiety disorder that appears to have a genetic basis. 3. There are certain physiological aspects of social phobia that separate it from the other anxiety disorders. 4. Support for a dopaminergic abnormality related to social phobia is supported by investigation studies and pharmacotherapy. 5. There are a number of studies reporting success in the treatment of social phobia with medications.

Adrenergic beta-Antagonists↗
PubMed1992

Fractures of the mandible and maxilla.

External fixation is an effective method for stabilization of many mandibular fractures. Thorough physical examination and patient stabilization should be instituted before attending to the fractures and associated soft tissue trauma. Normal occlusion rather than perfect reduction is the goal of oral fracture repair. Loose teeth or teeth in the fracture should be removed, as should any avascular bone fragments. Soft tissue wounds should be treated as for any contaminated wound. Mucosal wounds are allowed to heal by second intention. Although prophylactic perioperative antibiotics are indicated, they are usually not needed postoperatively. The three basic types of external fixators described include the Kirschner-Ehmer splint, pins or screws and acrylic, and the biphase splint. All three types are relatively easy to apply, and the principles of their application are similar. A minimum of two pins or screws are placed percutaneously in each fragment, avoiding the mandibular canal. The Kirschner-Ehmer splint is more easily adjustable than the biphase splint or the pin-acrylic splint, which use acrylic connecting bars. The advantages of fixators that use acrylic bars are that the pins or screws need not all be in the same plane and that they are more lightweight than the Kirschner-Ehmer splint. The disadvantages of the biphase splint are its increased expense and its use being limited to larger dogs. External fixators are well tolerated by the animals, and postoperative care is minimal. Mandibular fractures are usually healed in 3 to 5 weeks, and the fixators can be removed with the animal under sedation.

Animals↗
PubMed1991

Predictors of response to monoamine oxidase inhibitors: do they exist?

Multiple regression analysis was conducted on potential response predictors in a double-blind study of monoamine oxidase inhibitors (MAOI) and placebo treatment in 130 depressed outpatients. Positive main effects were found for sex (female), lack of prior hospitalization, presence of precipitating events. A negative main effect was found for concurrent physical illness. Treatment x predictor effects were found for distinct quality and non-reactivity. Non-reactivity was associated with positive outcome in the active drug group, but with negative outcome in the placebo group [corrected]. Distinct quality demonstrated a more complex effect, its presence being associated with decreased improvement in the treatment group and greater improvement in the control group. No atypical depressive symptoms predicted MAOI response, and we were unable to characterize a specifically responsive MAOI syndrome.

Adult↗
PubMed1991

Post-traumatic stress disorder in the community: an epidemiological study.

Post-traumatic stress disorder (PTSD) was studied in the Piedmont region of North Carolina. Among 2985 subjects, the lifetime and six month prevalence figures for PTSD were 1.30 and 0.44% respectively. In comparison to non-PTSD subjects, those with PTSD had significantly greater job instability, family history of psychiatric illness, parental poverty, child abuse, and separation or divorce of parents prior to age 10. PTSD was associated with greater psychiatric comorbidity and attempted suicide, increased frequency of bronchial asthma, hypertension, peptic ulcer and with impaired social support. Differences were noted between chronic and acute PTSD on a number of measures, with chronic PTSD being accompanied by more frequent social phobia, reduced social support and greater avoidance symptoms.

Adolescent↗
PubMed1991

Diagnostic issues in posttraumatic stress disorder: considerations for the DSM-IV.

Four issues of key interest with regard to posttraumatic stress disorder in the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) are discussed. These include: (a) how to define the stressor criterion, especially, whether or not the victim's response ought to be included and whether low-magnitude traumas qualify etiologically; (b) the cohesiveness of the syndrome and the validity of items across stressor groups; (c) the position of posttraumatic stress disorder within DSM-IV; and (d) comorbidity with other illnesses.

Dissociative Disorders↗
PubMed1991

The Brief Social Phobia Scale.

An observer measure of social phobic symptoms, referred to as the Brief Social Phobia Scale, consists of 11 items, 7 evaluating commonly feared or avoided situations and 4 additional items measuring autonomic distress. Symptoms represented by the scale items are found frequently in social phobia, and the instrument demonstrates acceptable interrater and test-retest reliability, internal consistency, concurrent validity against other measures of social phobia, and the ability of patients to change as a result of treatment. It can also detect differences between active treatment and placebo treatment. A comparison of the sensitivity of this scale with other scales in detection of size of effect also is presented.

Humans↗