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Biomedical subjects

J R Davidson

Publications and source records attributed to J R Davidson.

At least 145 records · Page 8Linked to original sources

Long-term treatment of social phobia with clonazepam.

Twenty-six socially phobic outpatients were treated with clonazepam for the relief of symptoms. At evaluation, which took place after an average of 11.3 months of continuous treatment, 22 (84.6%) patients showed good improvement and 4 (14.4%) showed no improvement or were not recovered. The dose declined over time, from a peak mean of 2.1 mg/day to a mean of 0.94 mg/day at follow-up. Side effects are described, along with individual case descriptions that illustrate important aspects of the use of benzodiazepines for the treatment of social phobia.

Adult↗

Levels of urinary free cortisol in social phobia.

Levels of urinary free cortisol were measured in 10 patients with social phobias and in 15 age- and sex-matched normal controls. No differences were found either in cortisol levels or in the ratio of free cortisol to creatinine. These nonsignificant differences between groups do not necessarily rule out the possibility that the hypothalamic-pituitary-adrenal axis may be altered in individuals with social phobia.

Adult↗

Growth hormone and cortisol secretion in relation to sleep and wakefulness.

The study investigated secretory patterns of growth hormone (GH) and cortisol in relation to sleep and wakefulness. Plasma hormone levels were monitored in 10 young men during baseline waking and sleeping, during 40 hours of wakefulness, and during sleep following deprivation. The normal nocturnal GH surge disappeared with sleep deprivation, and was intensified following sleep deprivation. Mean GH levels were higher during slow wave sleep (SWS) compared with other sleep stages. During sleep after deprivation, GH secretion was prolonged, and second GH peaks occurred in three subjects which were not associated with SWS. Average 24-hour cortisol levels were not altered by sleep deprivation or sleep following deprivation, but the nocturnal cortisol rise occurred approximately one hour earlier with sleep deprivation and one hour later with resumed sleep, compared to baseline. This effect on the timing of the rise is consistent with an initial inhibitory influence of sleep on cortisol secretion. The results demonstrate that: the nocturnal growth hormone surge is largely sleep-dependent; temporal associations between GH and SWS are not reliable after sleep deprivation; although the cortisol rhythm is not sleep-dependent, the timing of the cortisol rise may be influenced by sudden changes in the sleep-wake schedule.

Adult↗

Continuation treatment of panic disorder with high-potency benzodiazepines.

High-potency benzodiazepines such as clonazepam and alprazolam are effective and safe in the short-term treatment of panic disorder, but less is known about their effectiveness and safety over the long term. Further understanding of these issues is important since panic disorder is usually chronic and may call for long-term treatment. Available naturalistic data suggest that tolerance to the antipanic or antiphobic effects of clonazepam and alprazolam does not occur in panic disorder/agoraphobia; doses also tend to decrease over time. Withdrawal symptoms occur after short-term treatment with alprazolam, but less is known about clonazepam in this respect. Other issues discussed include management of withdrawal, clinical use of benzodiazepines, importance of comorbidity, and the use of benzodiazepines in association with behavior therapy.

Agoraphobia↗

Classification of depression by grade of membership: a confirmation study.

One hundred and thirty out-patients with depression were studied by grade of membership multivariate (GOM) analysis. Five depressive types were generated. Pure Type I represented a mild form of melancholia in older, stable males, who showed a modest drug response. Pure Type II included obsessive-anxious symptoms in older patients who responded well to an MAOI drug, but poorly to placebo. Pure Type III was a mildly symptomatic form of depression which responded well to placebo. Pure Type IV included features of agitation, mood worsening later in the day, anorexia and depersonalization; it was commonly precipitated by external stress and MAOI treatment was more effective than placebo. In Pure Type V depression, patients were mostly younger females with high levels of symptomatology, atypical vegetative symptoms, unstable life-styles, disadvantaged backgrounds and a poor response to MAOI and placebo. These results resemble in many ways our earlier GOM study of depression, as well as other multivariate studies of depression in the literature.

Adult↗

Effects of sleep deprivation on human immune functions.

The effect of 40 h of wakefulness on a variety of immunological parameters in the peripheral blood from 10 normal male subjects was studied. Sleep deprivation led to enhanced nocturnal plasma interleukin 1-like and interleukin 2-like activities. The rise in nocturnal response of lymphocytes to pokeweed mitogen stimulation during a normal 24 h sleep-wake cycle was delayed by sleep deprivation, but the response to the phytohemagglutinin mitogen was unaffected. With resumed nocturnal sleep, there was a prolonged decline in natural killer cell activity (measured as spontaneous cytolytic activity for human tumor cells) and return of an increased response to pokeweed mitogen. The altered patterns in immune functions occurred independently of the cortisol circadian rhythm, which remained unchanged.

Adult↗

Pharmacotherapy in posttraumatic stress disorder: historical and clinical considerations and future directions.

Posttraumatic stress disorder (PTSD) has long been recognized as responsive to drug and somatic treatments. Clinical characteristics and patterns of treatment response were well described in the 1940s. Recent studies indicate that tricyclic antidepressants and monoamine oxidase inhibitors (MAOIs) have specific ameliorative effects on PTSD symptoms, but further work is needed in this regard. Goals of drug therapy are provided and future directions suggested.

Humans↗

An efficacy study of isocarboxazid and placebo in depression, and its relationship to depressive nosology.

Isocarboxazid and placebo were evaluated in 130 anxious depressives. Drug was superior to placebo on depression, anxiety, interpersonal sensitivity, and global measures, and on symptoms of hostility, anxiety, obsessiveness, and psychological-cognitive components of depression. There were no significant differences between treatment effects on psychomotor and typical vegetative symptoms. Isocarboxazid was more effective than placebo in major, but not in minor, depression. It was significantly more effective in depression classified as endogenous depression or melancholia by various diagnostic criteria. Drug was more effective than placebo in atypical depression with vegetative reversal and in Brief Psychiatric Rating Scale (BPRS)-derived profiles of anxious and hostile depression; there were no drug-placebo differences in atypical depression without vegetative reversal, or in BPRS retarded and agitated/excited depression. Interpersonal sensitivity emerged as an important drug-responsive dimension.

Adult↗

A comparative evaluation of three discriminant scales for endogenous depression.

Three discriminant scales for diagnosing endogenous depression were examined in 56 depressed inpatients. These scales were the Newcastle 1 (N1), Newcastle 2 (N2), and Michigan Index (MI). The scales agreed on diagnosis in 17 (30%) patients; respective frequencies of endogenous depression were 23%, 57%, and 78% for the N2, N1, and MI scales. Relationships were examined between treatment response to isocarboxazid, drug dose, and diagnostic type for each scale. Significant dose X diagnosis interactions were noted for N1 and N2, but not for MI. A correlational within-dose analysis of all three scales revealed that actual diagnostic score was related to outcome only for high-dose patients on the Newcastle-1 scale; no other significant correlations emerged.

Adult↗

Diagnostic utility of the dexamethasone suppression test.

This article discusses the current controversy surrounding the diagnostic utility of the Dexamethasone Suppression Test, addresses the questions raised by the recent editorial by Ross in this journal, discusses the general principles behind the development of tests, and estimates their diagnostic utility. This discussion aims to clarify some aspects of the controversy. It presents an operational analysis of the Dexamethasone Suppression Test as utilized at a state hospital. This operational analysis shows that the test may be useful in distinguishing schizophrenia from psychotic depression, and mania from schizophrenia. Furthermore, it shows that the test is not useful as a screening test. These results are compared with those obtained by other investigators. The authors further show how test results can be used rationally by clinicians by so-called threshold analysis. Clinical data from a state hospital are used to illustrate this.

Dexamethasone↗

Epidermoid cyst of the spleen.

Epidermoid cysts of the spleen are extremely rare, occurring mainly in people under 20 years of age. They are thought to originate from an abnormality in the development of the spleen during the seventh week of embryological life, when the spleen is close to the mesonephric tissues. Cysts present as an asymptomatic abdominal mass or with pain in the left upper quadrant and/or the left shoulder. In the past the recommended treatment has been splenectomy, but with the changing attitudes towards splenic surgery a more conservative approach is now employed. Drainage under radiographic guidance, deroofing with external drainage or simply deroofing with drainage into the peritoneal cavity are now more popular techniques (along with simple cystectomy). Complications are few, although those associated with deroofing and internal drainage are inadequately investigated.

Adult↗