Effects of dexamethasone on declarative memory function in posttraumatic stress disorder

Alterations in the hypothalamic-pituitary-adrenal (HPA) axis and hippocampal-based memory have been associated with posttraumatic stress disorder (PTSD), and the administration of exogenous glucocorticoids has been shown to result in a transient verbal declarative memory impairment in healthy human subjects. The purpose of this study was to assess the effects of the glucocorticoid dexamethasone on verbal declarative memory function in patients with PTSD. Forty-two men and women with (n=14) and without (n=28) PTSD received placebo or dexamethasone (1 and 2 mg on two successive days) in a double-blind, randomized fashion. Declarative memory was assessed with paragraph recall at baseline (day 1) and day 3. There was a significant interaction between diagnosis and drug (dexamethasone vs. placebo) on paragraph recall related to a relative detrimental effect of dexamethasone on memory function in healthy subjects, but not those with PTSD. These findings are consistent with an altered sensitivity of declarative memory function in PTSD to regulation by glucocorticoids, possibly explainable by alterations in glucocorticoid receptors in the hippocampus or other brain regions mediating declarative memory.     

睡眠剥夺对健康青年男性工作记忆的影响及莫达非尼的干预作用

目的 探讨不同时间睡眠剥夺对健康青年男性工作记忆的影响,以及莫达非尼对睡眠剥夺的对抗作用. 方法 10名健康男性青年志愿者进行间隔1周的3次36 h睡眠剥夺,第一次不服药,为剥夺组,后2次志愿者交叉服用莫达非尼和安慰剂(于睡眠剥夺14 h和24h 2次服用1.每次服药后3 h进行工作记忆任务测试(倒数n项测验),剥夺组也在同样的时间进行测试.把睡眠剥夺前清醒时设为正常对照组.并进行测试. 结果 剥夺组的1-back任务的第2次测试平均反应时间较第1次测试明显延长,2-back任务的第2次测试平均反应时间、错误率较第1次测试明显增高,差异均有统计学意义(P＜0.05).剥夺组的l-back任务的第2次测试错误率与平均反应时间均比正常对照组明显增高,2-back任务的两次测试平均反应时间和错误率较正常对照组明显增高,差异均有统计学意义(P＜0.05).莫达非尼组的1-back任务的第2次测试平均反应时间较剥夺组明显降低,2-back任务的两次测试平均反应时间和错误率较剥夺组明显降低,差异均有统计学意义(P＜0.05). 结论 睡眠剥夺后工作记忆受到损害,并随着剥夺时间延长,受损加重.莫达非尼对睡眠剥夺后的工作记忆损害有明显的改善作用.     

Influence of desglycinamide-(arg8) vasopressin on memory in healthy subjects

In 12 healthy student volunteers the influence on memory, attention and mood of a single dose of 2 mg of the vasopressin analog, desglycinamide-(arg8) vasopressin (DGAVP), given by the nasal route was investigated. On day 1 all subjects received placebo (single-blind), 1 week later they were given either DGAVP or placebo (double-blind). Memory effects were measured with the Buschke restrictive reminding method. DGAVP significantly improved storage processes, with retrieval processes less affected. Attention and mood processes were not influenced. It is suggested that DGAVP has an influence on memory processes.     

Effects of lithium, nortriptyline and dexamethasone on insulin sensitivity

1. The effects of lithium, dexamethasone, nortriptyline and their combinations on insulin sensitivity, expressed as a drop of plasma glucose in response to insulin challenge, were investigated in healthy volunteers.

2. Short-term (three weeks) lithium treatment did not appear to exert any influence on the insulin sensitivity.

3. Dexamethasone administered alone (2 mg given 57 hours prior to the test) had no effect on the insulin sensitivity of drug-free healthy subjects. However, after three weeks of lithium treatment the dexamethasone premedication resulted in slight flattening of glucose response to insulin in the same persons.

4. Nortriptyline administered for three weeks to healthy volunteers, pretreated with dexamethasone, increased insulin sensitivity.

5. These findings may have clinical implications regarding the treatment of depressed diabetic patients, and may provide information about the regulation of insulin sensitivity.     

Dexamethasone is not superior to placebo for treating lumbosacral radicular pain

In a prospective double-blind study, we compared dexamethasone and placebo in 33 subjects with lumbosacral radicular pain. Of subjects with resting pain, 7/21 improved on dexamethasone, and 4/12 improved on placebo. Of subjects with pain on straight-leg raising, 8/19 improved on dexamethasone and 1/6 on placebo. Of 27 subjects evaluated 1 to 4 years after treatment, 8/16 who had received dexamethasone were asymptomatic or had only occasional mild low-back pain, compared with 7/11 who had received placebo. Thus, dexamethasone is not superior to placebo for either early or long-term relief of lumbosacral radicular pain, but may reduce pain evoked by stretch of acutely inflamed spinal nerve roots.     

Amphetamine, psychosis, and cognition in the schizophrenia spectrum

We previously reported that subjects with a schizophrenia spectrum personality disorder (ie, an odd cluster personality disorder), of which the prototype is schizotypal personality disorder, show cognitive impairment in circumscribed areas (working memory) compared with healthy control subjects, and that amphetamine administration improves working memory in subjects with schizotypal personality disorder. In this larger series, we wanted to determine whether amphetamine treatment ameliorates working memory impairment using three groups: subjects with a schizophrenia spectrum personality disorder (ie, schizotypal, paranoid, or schizoid personality disorder), other (subjects with nonschizophrenia spectrum) personality disorder, and healthy volunteers. We hypothesized that amphetamine treatment would improve cognitive function in domains in which subjects with schizophrenia spectrum personality disorder show impairment compared with healthy volunteers and the other personality disorder group. Overall, amphetamine treatment did not improve performance in any task compared with placebo, and there was no group by drug interaction in the total sample. However, when the sample was restricted to the subjects who showed impairment at baseline, amphetamine treatment improved visuospatial working memory. In the total patient sample, amphetamine treatment reduced negative symptoms, whereas positive symptoms remained unchanged. Amphetamine treatment improves working memory in those subjects with cognitive impairment at baseline, most of whom meet criteria for a schizophrenia spectrum disorder.     

Effects of glucocorticoids on declarative memory function in major depression.

BACKGROUND: Major depression has been associated with hypercortisolemia in a subset of patients with depression. Administration of exogenous cortisol and other glucocorticoids to healthy human subjects has been observed to result in a transient impairment in verbal declarative memory function. The purpose of this study was to assess the effects of the glucocorticoid, dexamethasone, on verbal declarative memory function in patients with untreated unipolar major depressive disorder (MDD). METHODS: Fifty two men and women with (n = 28) and without (n = 24) MDD received placebo or dexamethasone (1 mg and 2 mg on 2 successive days) in a double-blind, randomized fashion. Declarative memory was assessed with paragraph recall at baseline (day 1) and day 3. RESULTS: There was a significant interaction between diagnosis and drug (dexamethasone vs. placebo) on paragraph recall. In the healthy subjects, memory improved from baseline to day 3 with placebo and was unchanged with dexamethasone, whereas in MDD patients memory function showed a pattern of decreasing with placebo and improving with dexamethasone from baseline to day 3. CONCLUSIONS: These findings are consistent with an altered sensitivity of declarative memory function in MDD to regulation by glucocorticoids. Possible explanations of the findings include alterations in glucocorticoid receptors in the hippocampus or other brain regions mediating declarative memory, or differential sensitivity to dexamethasone-induced reductions in cortisol, in patients with MDD.     

Sleep, age, depression and the cholinergic REM induction test with RS 86.

1. Healthy volunteers and patients with a major depressive disorders were administered 1.5 mg RS 86 (a cholinergic agonist) and placebo in a randomized double-blind cross-over design at 10 p.m. prior to bedtime. 2. Polysomnographic recordings demonstrated a significantly more pronounced shortening of REM latency after cholinergic stimulation in depressed patients compared to healthy subjects. 3. Even those depressed patients displaying placebo REM latencies in the normal range showed sleep onset REM periods after cholinergic stimulation. 4. The results support the reciprocal interaction model of NonREM-REM sleep regulation and the cholinergic-aminergic imbalance model of depression.     

Taste thresholds in man are differentially influenced by hydrocortisone and dexamethasone

The present study focused on sensory processing (taste threshold) in healthy young men given different cortisol doses within the normal physiological range. It aimed to differentiate the effects of dexamethasone, a synthetic pure glucocorticoid, compared to hydrocortisone, which has both glucocorticoid and mineralocorticoid properties. In a double-blind, cross-over design, 18 male subjects participated in three sessions. Subjects were pretreated orally with hydrocortisone (50 mg), dexamethasone (2 mg) or placebo. Taste detection was tested by a forced-choice three stimulus drop technique to determine detection acuity and a signal detection procedure to determine the ability to detect differences in NaCl concentration. Cortisol concentrations were determined in blood and saliva.

Hydrocortisone and dexamethasone had opposite effects on taste detection acuity. With the highest cortisol levels after intake of hydrocortisone, subjects made more errors is detection trials with respect to stimuli close to the absolute taste detection threshold than after intake of dexamethasone. Detection of differences was impaired by both glucocorticoids. This type of behavioral study in man may help clarify the roles of heterogenous corticosteroid receptor systems within the human brain.     

Neurohormonal responses to cholecystokinin tetrapeptide: a comparison of younger and older healthy subjects

We recently found that, compared with younger healthy subjects, older healthy subjects had less symptomatic and cardiovascular response to the panicogenic agent cholecystokinin tetrapeptide (CCK-4). As an exploratory part of that study, we also evaluated the effect of aging on neurohormonal responses to CCK-4. These hormonal data are the focus of this article. Forty healthy volunteers aged 20-35 years and 40 healthy volunteers aged 65-81 years, divided equally between men and women, were compared on their hormonal responses (maximum change from baseline in growth hormone [GH], prolactin, adrenocorticotropic hormone [ACTH], and cortisol) to the intravenous administration of 50 microg of CCK-4 or placebo. Blood samples for serum hormone determination were collected at 2 minutes prior to the intravenous challenge (baseline) and at 2, 5, and 10 minutes after the challenge. In both age groups, maximum increase in prolactin, ACTH and cortisol was significantly greater with CCK-4 than with placebo. Following administration of CCK-4, younger and older groups did not significantly differ in maximum increase in prolactin, ACTH, or cortisol. Older subjects had a statistically significant smaller increase in GH compared with younger subjects but the magnitude of the difference was small and of doubtful clinical relevance. Older subjects who had a panic attack had significantly greater elevations of all hormones compared with those who did not panic and younger panickers had a significantly greater elevation of GH compared with young nonpanickers. For the most part, maximum changes in hormonal levels were not correlated with symptom severity, suggesting that other factors may have contributed to the differential effect of panic on the HPA axis.     

The effects of homeopathic belladonna 30CH in healthy volunteers -- a randomized, double-blind experiment

OBJECTIVES: The practice of homeopathy rests on symptoms, which have been produced by medicinal substances in healthy volunteers, often applied at ultramolecular dilutions. It is unknown whether these symptom patterns are due to specific effects or chance fluctuation. METHODS: We tested the hypothesis that a homeopathic substance can bring about symptoms different from observation and placebo in a double-blind, placebo-controlled crossover design with baseline observation. RESULTS: 87 out of 118 healthy volunteers took both placebo and homeopathic belladonna 30CH in random sequence, after a 2-week observation period, and finished the 8-week trial. Apart from an insignificant tendency for subjects to report more symptoms with belladonna (mean number: 27.34), as compared to observation (24.26) or placebo (24.17), there was no indication that subjects reacted differently to homeopathy than to placebo or during baseline. CONCLUSION: There is no indication that belladonna 30CH produces symptoms different from placebo or from no intervention. Symptoms of a homeopathic pathogenetic trial (HPT) are most likely chance fluctuations.     

The dexamethasone suppression test: importance of dexamethasone concentrations

Plasma dexamethasone concentrations and cortisol response to dexamethasone were measured in 29 normal healthy volunteers, 23 depressed patients, and 10 patients with anorexia nervosa at 4:00 PM postdexamethasone. In each of the 3 groups, nonsuppressors had lower dexamethasone concentrations than suppressors. Of the subjects with plasma dexamethasone at or below 0.7 ng/ml, a significantly higher proportion (48%) were nonsuppressors compared to the proportion above 0.7 ng/ml (14%), all of whom were patients. Plasma dexamethasone concentrations in a subgroup of depressed nonsuppressors were high (mean 1.35 ng/ml), whereas the remainder were low (0.42 ng/ml) and were similar to the normal nonsuppressors (0.35 ng/ml), suggesting different mechanisms for nonsuppression in the subgroups. Plasma dexamethasone concentrations were similar in nonendogenous and endogenous depressives, in men and women, and in medicated and drug-free patients. None of the variables of age, weight, history of weight loss, Hamilton depression rating score, predexamethasone cortisol, or postdexamethasone cortisol were significantly correlated with plasma dexamethasone, except for body weight and a history of weight loss in the depressed group only. Mean plasma dexamethasone concentrations increased significantly from week 1 to week 2 in 7 depressed patients, whereas plasma cortisol decreased; however, the relationship between dexamethasone and cortisol varied considerably for individual patients.     

Falls and stumbles in myotonic dystrophy

OBJECTIVE: To investigate falls and risk factors in patients with myotonic dystrophy type 1 (DM1) compared with healthy volunteers. METHODS: 13 sequential patients with DM1 from different kindreds were compared with 12 healthy volunteers. All subjects were evaluated using the Rivermead Mobility Index, Performance Oriented Mobility Assessment, and modified Activities Specific Balance Confidence scale. Measures of lower limb muscle strength, gait speed, and 7-day ambulatory activity monitoring were recorded. Subjects returned a weekly card detailing stumbles and falls. RESULTS: 11 of 13 patients (mean age 46.5 years, seven female) had 127 stumbles and 34 falls over the 13 weeks, compared with 10 of 12 healthy subjects (34.4 years, seven female) who had 26 stumbles and three falls. Patients were less active than healthy subjects but had more falls and stumbles per 5000 right steps taken (mean (SD) events, 0.21 (0.29) v 0.02 (0.02), p = 0.007). Patients who fell (n = 6) had on average a lower Rivermead Mobility score, slower self selected gait speed, and higher depression scores than those who did not. CONCLUSIONS: DM1 patients stumble or fall about 10 times more often than healthy volunteers. Routine inquiry about falls and stumbles is justified. A study of multidisciplinary intervention to reduce the risk of falls seems warranted.     

Anterograde amnesia with oral lorazepam

Twelve healthy volunteers were enrolled in a double-blind placebo-controlled study to evaluate the amnestic effects of orally administered lorazepam. The subjects were tested for immediate and delayed recall, using a word recall memory task. The subjects taking lorazepam did not differ from subjects receiving placebo on immediate recall. However, the delayed recall scores of lorazepam subjects were significantly lower compared to the placebo group (p less than .01).     

The dexamethasone and cortisol suppression test in depression: beta-endorphin as a useful marker

To investigate the mechanism underlying disturbances in hypothalamopituitary-adrenal (HPA) function in depressed patients, the dexamethasone suppression test (DST) was compared with a cortisol suppression test (CST) and placebo treatment in depressed patients and control subjects. Plasma levels of cortisol, ACTH and beta-endorphin were assessed at 3 times during the day after treatment with a single dose of exogenous steroid. Both dexamethasone and cortisol treatment resulted in suppression of cortisol, ACTH and beta-endorphin in control subjects, while neither treatment had any effect on the hormone levels in those depressed patients who showed cortisol nonsuppression after dexamethasone. In the depressed patients who were cortisol suppressors after dexamethasone, cortisol treatment only slightly changed plasma levels of beta-endorphin, although they were suppressed after dexamethasone treatment. In addition, high levels of both cortisol and beta-endorphin were observed after placebo treatment in all depressed patients compared to control subjects, probably due to the absence of the normally occurring decrease of these hormones during the day in these patients. Cortisol treatment, but not dexamethasone treatment, discriminated depressed patients from controls with respect to their beta-endorphin plasma levels. However, it is not yet clear whether these different effects of the two steroids are related to a different mode of action of these steroids in depressed patients. beta-Endorphin seems to be a useful marker in detecting disturbances in HPA function among depressed patients.     

Cortisol activity and cognitive changes in psychotic major depression

OBJECTIVE: The theory that psychotic major depression is a distinct syndrome is supported by reports of statistically significant differences between psychotic and nonpsychotic major depression in presenting features, biological measures, familial transmission, course and outcome, and response to treatment. This study examined differences in performance on a verbal memory test and in cortisol levels between patients with psychotic and nonpsychotic major depression and healthy volunteers. METHOD: Ten patients with psychotic major depression, 17 patients with nonpsychotic major depression, and 10 healthy volunteers were administered the Wallach Memory Recognition Test and had blood drawn at half-hour intervals over the course of an afternoon to assay cortisol levels. RESULTS: Subjects with psychotic major depression had a higher rate of errors of commission on the verbal memory test (incorrectly identified distracters as targets) than did subjects with nonpsychotic major depression or healthy volunteers; errors of omission were similar among the three groups. Subjects with psychotic major depression had higher cortisol levels throughout the afternoon than subjects with nonpsychotic major depression or healthy volunteers. This effect became even more pronounced later in the afternoon. CONCLUSIONS: Psychotic major depression is endocrinologically different from nonpsychotic major depression and produces cognitive changes distinct from those seen in nonpsychotic major depression.     

A neuroendocrine test battery in bipolar patients and healthy subjects

Abnormalities of hormonal responses to a number of neuroendocrine challenges have been reported in depressed patients. Most studies have examined responses in a single neuroendocrine axis. We used a series of four neuroendocrine challenges (thyrotropin-releasing hormone test, gonadotropin-releasing hormone test, insulin tolerance test, and dexamethasone suppression test) to examine eight hormonal responses in 22 healthy subjects and 22 patients with bipolar disorder. Variability of hormonal responses in bipolar patients was examined by evaluating the number of abnormal hormonal responses as compared with responses from healthy volunteers. Abnormalities were observed after all four neuroendocrine tests. Nine control subjects (40.9%) and 17 bipolar patients (77.3%) had at least one abnormal response. More strikingly, 12 bipolar patients (54.5%), but no controls, had two or more abnormal responses. These findings suggest that manic-depressive patients show increased variability in hormonal response from multiple neuroendocrine axes.     

Congnitive dissonance, stress and virus-induced common colds.

A study of the effect of cognitive dissonance on symptoms of rhinovirus-induced common colds and their infectivity in 48 volunteers is presented. Subjects, about to be experimentally infected with two common cold viruses (rhinoviruses), were given a choice as to whether or not to receive a “trial anti-viral drug” (in fact a placebo) during the course of their infection. To make this choice difficult, they were also told that if they received the “drug”, their gastric juices would have to be sampled by means of a stomach tube at the end of the experiment. It was predicted from Cognitive Dissonance Theory that all those making this choice, irrespective of the alternative chosen, would justify their decisions by “attenuating” the experienced severity of their colds, and that this effect would be evidenced in their symptoms and possibly in the amount of virus shed as compared to controls who were neither given the placebo nor the choice concerning it.An effect exactly opposite to that predicted was obtained. Symptoms, but not virus shedding were significantly influenced by the psychological manipulations involved, the symptoms of subjects given a choice being more severe than those of subjects not choosing. Interpretations of this are explored.     

Endocrinological effects of high-dose Hypericum perforatum extract WS 5570 in healthy subjects

In this single-blind study, the effects of acute oral administration of high-dose Hypericum perforatum extract WS 5570 on the cortisol (COR), adrenocorticotropic hormone (ACTH), growth hormone (GH), and prolactin (PRL) secretions were examined in 12 healthy male volunteers. In a randomized order, the subjects received placebo or WS 5570 at several dosages (600, 900, and 1,200 mg) at 08.00 h on 4 different days. After insertion of an intravenous catheter, blood samples were drawn 1 h prior to administration of placebo or WS 5570 (600, 900, or 1,200 mg), at the time of administration, and during 5 h thereafter at intervals of 30 min. The serum concentrations of COR, GH, and PRL as well as the plasma levels of ACTH were determined in each blood sample by means of double antibody radioimmunoassay, fluoroimmunoassay, and chemiluminescence immunometric assay methods. The area under the curve value was used as parameter for COR, ACTH, GH, and PRL responses. Repeated-measures Anova revealed a significant stimulatory effect of WS 5570 on the ACTH secretion, whereas COR and PRL secretions were not significantly influenced. Moreover, there was a stimulatory peak of GH release 240 min after challenge with WS 5570 in some but not all volunteers, without reaching statistical significance in comparison with placebo. Mean arterial blood pressure and heart rate remained unchanged after administration of WS 5570. Apparently, WS 5570 at the dosages given in this study inconsistently causes endocrinological effects in healthy subjects by influencing central neurotransmitters.     

Effect of homocysteine reduction by B-vitamin supplementation on markers of clotting activation

Homocysteine may have an effect on risk of cardiovascular disease by stimulating procoagulant factors and/or impair anti-coagulant mechanisms or fibrinolysis. However, data in humans of such effects are sparse. In this intervention study, we examined the effect of homocysteine lowering by B-vitamin supplementation on prothrombin fragments 1 and 2 (F1 + 2), thrombin-antithrombin complex (TAT), and fibrin degradation products (D-dimer). The study comprised 118 healthy volunteers, 50 with homocysteine > 16 mumol/L and 68 with homocysteine < or = 16 mumol/L, who were randomized to placebo or high-dose B-vitamin supplements (5 mg folic acid, 0.4 mg hydroxycobalamin, and 50 mg pyridoxine) daily for 8 weeks. Although homocysteine concentrations were 27.7% (p < 0.0001) reduced in the B-vitamin group compared to the placebo group, no effect on F1 + 2 and TAT concentrations was observed. A 10.4% reduction was observed for D-dimer (p = 0.08). In conclusion, it appears that in healthy subjects homocysteine reduction by B-vitamin supplementation has a modest beneficial effect on clotting activation.