Showing papers in "Neuropsychobiology in 1995"
TL;DR: No important differences existed between volunteers' and patients' baseline and/or placebo performances and both groups responded similarly to comparable drugs/doses, but ondansetron, none, produced marked and pervasive driving impairment, which lasted throughout treatment.
Abstract: Effects of benzodiazepine (diazepam, lorazepam) and benzodiazepine-like anxiolytics (alpidem, suriclone) and a 5-HT-3 antagonist (ondansetron) on actual driving performance were measured in three doub
136 citations
TL;DR: Changes in mood after a year occurred even though the blood status of 9 vitamins reached a plateau after 3 months: this improvement in mood was associated in particular with improved riboflavin and pyridoxine status.
Abstract: The possibility that the taking of vitamin supplements may influence mood was explored. One hundred and twenty-nine young healthy adults took either 10 times the recommended daily dose of 9 vitamins,
114 citations
TL;DR: In the current investigation, the DR+ T cells were not found to be associated with age of the autistic patients but were inversely correlated with a decreased plasma level of the C4B protein.
Abstract: Autism is a developmental disorder characterized by severe communication, social and behavioral abnormalities. Over the past several years a fair amount of evidence has accumulated suggesting that som
94 citations
TL;DR: It is concluded that one or more genes of the MHC is (are) involved in the development of some cases of autism.
Abstract: Autism likely results from several different etiologies or a combination of pathological mechanisms. Recent studies suggest that this disorder may be associated with immune abnormalities, pathogen-autoimmune processes and perhaps the major histocompatibility complex (MHC). In a preliminary study we found that 22 autistic subjects had an increased frequency of the extended or ancestral MHC haplotype B44-SC30-DR4. The current study attempted to confirm this observation by studying 23 additional randomly chosen autistic subjects, most of their parents and 64 unrelated normal subjects. In agreement with earlier findings B44-SC30-DR4 was associated with autism. In combining the data from the original and current studies, B44-SC30-DR4 or a substantial fragment of this extended haplotype was represented in 40% of the autistic subjects and/or their mothers as compared to about 2% of the unrelated subjects. It is concluded that one or more genes of the MHC is (are) involved in the development of some cases of autism.
91 citations
TL;DR: P300 amplitude was significantly lower in the 16 PTSD subjects as compared to the 10 subjects without PTSD, which supports information processing disturbances in PTSD.
Abstract: In the present study, P300 has been recorded in 26 subjects (15 women) 1 month after an aggression without organic complications. Among our sample, 16 subjects fulfilled DSM-III-R criteria for posttraumatic stress disorder (PTSD) and 10 did not. P300 amplitude was significantly lower in the 16 PTSD subjects as compared to the 10 subjects without PTSD. This study supports information processing disturbances in PTSD.
90 citations
TL;DR: The present study showed that the major associations were with current anxiety disorders, especially panic and related conditions, in the subgroup of migraine with aura; in the relatively few patients with mood disorders, depression was nearly always comorbid with panic or other anxiety disorders.
Abstract: Past epidemiological and clinical research has identified depression as the most common psychiatric disorder associated with headache. The present study carried out in a neurology headache clinic show
68 citations
TL;DR: Investigation of chronic fatigue syndrome patients found a statistically significant correlation between serum levels of total and free carnitine and clinical symptomatology, indicative of mitochondrial dysfunction, which may contribute to or cause symptoms of fatigue in patients.
Abstract: Carnitine is essential for mitochondrial energy production. Disturbance in mitochondrial function may contribute to or cause the fatigue seen in chronic fatigue syndrome (CFS) patients. One previous investigation has reported decreased acylcarnitine levels in 38 CFS patients. We investigated 35 CFS patients (27 females and 8 males); our results indicate that CFS patients have statistically significantly lower serum total carnitine, free carnitine and acylcarnitine levels, not only lower acylcarnitine levels as previously reported. We also found a statistically significant correlation between serum levels of total and free carnitine and clinical symptomatology. Higher serum carnitine levels correlated with better functional capacity. These findings may be indicative of mitochondrial dysfunction, which may contribute to or cause symptoms of fatigue in CFS patients.
59 citations
TL;DR: It is concluded that current evidence points to true performance-enhancing effects of caffeine, although the extent of these and the conditions under which caffeine is most effective have yet to be fully determined.
Abstract: We agree with the conclusions of a recent article in this journal [James, Neuropsychobiology 1994;30:124-125] that studies on the psychoactive effects of caffeine need to take into account the possibility that the results obtained might represent merely the reversal of deleterious effects of caffeine deprivation rather than an actual net benefit due to caffeine use. However, in a review of recent studies we find no unequivocal evidence of impaired psychomotor performance associated with caffeine withdrawal. This is in contrast to a clear deterioration of mood which occurs even after overnight caffeine deprivation. We concluded that current evidence points to true performance-enhancing effects of caffeine, although the extent of these and the conditions under which caffeine is most effective have yet to be fully determined. At the same time, the existence of significant detrimental effects of caffeine deprivation on psychomotor performance has not been ruled out.
59 citations
TL;DR: With this method, the activation process of the central nervous system during mental demand in a complex psychophysiological situation is investigated and two effects of psychometric tests on brain activity are differentiated: the actual mental demand itself and the influence on the vigilance level.
Abstract: The aim of this study was to investigate the activation process of the central nervous system during mental demand in a complex psychophysiological situation. A 17-channel quantitative topographical E
57 citations
TL;DR: Analysis of beat-to-beat control of heart rate and blood pressure gives important information about cardiac sympathetic and parasympathetic interaction, which could be used to study the possible link between anxiety and depressive disorders and increased cardiovascular morbidity.
Abstract: Symptoms of anxiety suggest autonomic dysfunction and most of the psychotropic agents used to treat anxiety and affective disorders have strong autonomic effects. This article describes the utility and importance of analysis of heart rate and blood pressure time series to study cardiac autonomic function in psychiatric research. The variability of heart rate between 0.15 and 0.5 Hz is related to respiratory sinus arrhythmia, and is modulated by cholinergic activity in both supine and standing postures, while the variability between 0.04 and 0.15 Hz is dually influenced by cholinergic and adrenergic mechanisms which can be used as a relative measure of sympathetic activity in standing posture. Analysis of beat-to-beat control of heart rate and blood pressure gives important information about cardiac sympathetic and parasympathetic interaction, which could be used to study the possible link between anxiety and depressive disorders and increased cardiovascular morbidity.
54 citations
TL;DR: The EEG patterns of the ISONAR-treated patients developed an increase in abnormalities in EEG patterns and theta/delta power, which indicates an organic brain syndrome in patients on ECT, which is the first report on a controlled study comparing the therapeutic and non-therapeutic effects of electroconvulsive treatment and isoflurane narcotherapy.
Abstract: This is the first report on a controlled study comparing the therapeutic and non-therapeutic (side) effects of electroconvulsive treatment (ECT) and isoflurane narcotherapy (ISONAR; deep anesthesias w
TL;DR: BITE symptoms and gravity improved significantly and equally in the two groups during the 4 months of therapy, and global EDI scores, depression and anxiety decreased but not significantly.
Abstract: Fifteen women with bulimia nervosa were treated with a 4-month course of combined cognitive-behavioral, nutritional and antidepressant therapy (5 with amineptine and 10 with fluvoxamine). Patients wer
TL;DR: There is no difference in any of these studied parameters between CFS patients and controls, and other lines of evidence suggest the presence of a possible functional mitochondrial abnormality.
Abstract: Patients with chronic fatigue syndrome (CFS) suffer from disabling physical and mental fatigue. Abnormalities in mitochondrial function can lead to fatigue and weakness. Ultrastructural mitochondrial abnormalities have been reported to be present in CFS patients. We obtained percutaneous needle muscle biopsies from 15 CFS patients and 15 age- and sex-matched controls. We investigated previously reported ultrastructural abnormalites in CFS: subsarcolemmal mitochondrial aggregates, intermyofibrillar mitochondrial aggregates, mitochondrial circumference, area, pleomorphism and the presence of compartmentalization of the inner mitochondrial membrane. All of the steps of tissue processing, electron microscopy and data abstracting and analysis were performed in a totally blinded fashion. All of our data were rigorously quantified. We found no difference in any of these studied parameters between CFS patients and controls. Although there is no ultrastructural mitochondrial abnormality in CFS patients, other lines of evidence suggest the presence of a possible functional mitochondrial abnormality.
TL;DR: The results show that the platelet level of 5-HT was significantly reduced in AD and there was no effect on the levels of its metabolite 5-hydroxyindoleacetic acid.
Abstract: The platelet has been suggested to be a peripheral model of the central seroton-ergic neuron. This investigation was carried out in order to test the hypothesis that levels of serotonin (5-HT) in the
TL;DR: The P300 ERP amplitude was significantly smaller in schizophrenics in remission at both Cz and Pz than in normals, and the significance of the smaller auditory P300 amplitude in schizophrenia is discussed.
Abstract: The P300 event-related potential (ERP) was recorded using the auditory oddball paradigm in 12 (6 male) schizophrenic (DSM-IIIR) patients in rigorously defined clinical remission. The ERP was also recorded in 10 (5 male) age-, sex- and education-matched control subjects. ERP latencies and amplitude were measured at Cz and Pz recording sites. Mean latencies of the P300 in schizophrenic patients in remission at Cz [343.6 +/- 31 (SD) ms] and Pz (346.15 +/- 30 ms) did not differ from those of normals (Cz: 332.8 +/- 23 ms, Pz: 323 +/- 38 ms). The P300 ERP amplitude was significantly (p < 0.05) smaller in schizophrenics in remission at both Cz (9.2 +/- 4.4 microV) and Pz (8.8 +/- 4.4 microV) than in normals (Cz: 13.3 +/- 2.90 microV; Pz: 12.71 +/- 4.18 microV). The significance of the smaller auditory P300 amplitude in schizophrenia is discussed.
TL;DR: Both EEG delta in microvolts and metabolic rate had similar diagnostic sensitivity, but PET had fewer false positives among normals and the left amygdala had the highest sensitivity and percent correct diagnosis of any brain area.
Abstract: Quantitative scalp EEG from 32 channels and the cerebral glucose metabolic rate from the 32 underlying cortical positions as assessed by positron emission tomography (PET) with 18F-2-deoxyg
TL;DR: Results suggest that, among smokers cigarette smoking may improve driving performance and that there may exist an optimal nicotine dose for the enhancement of cognitive and psychomotor function.
Abstract: A double-blind study was conducted to investigate the psychomotor effects of cigarette smoking on a 1-hour computer-based simulation of driving comprising continuous tracking and brake reaction time t
TL;DR: BMI, depression, anxiety and EDI scores improved significantly and equally in both groups during the 4 months of therapy, while BITE scores did not change.
Abstract: Thirteen women with anorexia nervosa, binge-eating/purging type (AN-BP), 17-43 years old, were treated with a 4-month course of combined cognitive-behavioral, nutritional and antidepressant therapy (7 with amineptine and 6 with fluoxetine). Patients were monitored before and after 1, 2 and 4 months of treatment for body mass index (BMI), for eating disorder symptoms by the Eating Disorder Inventory (EDI) and the Bulimic Investigation Test (BITE) and for depression and anxiety by the Hamilton Rating Scales for Depression and for Anxiety. BMI, EDI scores, depression and anxiety improved significantly and equally in the two groups during the 4 months of therapy, while BITE scores did not change.
TL;DR: Results add to the body of data linking the GABA-benzodiazepine system of the lateral/basolateral nuclei to the amnestic effects induced by peripheral as well as central administration of benzodiazepines.
Abstract: Recent findings indicate that the memory-impairing effects of benzodiazepines may preferentially involve the basolateral nucleus of the amygdala To test this hypothesis we examined the effects on pretrial injection of diazepam into the central as compared to the lateral/basolateral amygdaloid nuclei on memory for a conditioned avoidance response Rats were implanted bilaterally with cannulae directed to either the central or lateral/basolateral amygdaloid nuclei Five to 7 days later they were trained on a multitrial inhibitory avoidance (step-down) task to criterion and tested 48 h later Fifteen minutes before training they were given an injection of either vehicle or diazepam (07 or 14 nmol) into the central or lateral/basolateral nuclei Administration of diazepam into the lateral/basolateral nuclei but not the central nucleus induced anterograde amnesia These results add to the body of data linking the GABA-benzodiazepine system of the lateral/basolateral nuclei to the amnestic effects induced by peripheral as well as central administration of benzodiazepines
TL;DR: BMI, EDI scores, depression and anxiety improved significantly and equally in the two groups during the 4 months of therapy, while BITE scores did not change.
Abstract: Twenty-two female patients with anorexia nervosa, restricted type, 14-35 years old, were treated with a 4-month course of combined cognitive-behavioral therapy, nutritional counselling and antidepressant drugs (nortriptyline for 7, fluoxetine for 15). Patients were monitored for body mass index (BMI), for eating disorder symptoms by the Eating Disorder Inventory (EDI) and the Bulimic Investigation Test (BITE) and for depression and anxiety by the Hamilton Rating Scales for Depression and for Anxiety (HRS-D and -A). The scores were determined before and after 1, 2 and 4 months of therapy. BMI, depression, anxiety and EDI scores improved significantly and equally in both groups during the 4 months of therapy, while BITE scores did not change.
TL;DR: 13 obsessive-compulsive patients were studied with quantitative EEG and auditory and visual evoked potentials and six of them were studied also with perfusion single photon emission tomography, discussing the results in the context of current data about serotonergic neurotransmission.
Abstract: An abnormally increased glucose metabolism has been described with positron emission tomography (PET) in frontal and caudate regions of obsessive-compulsive patients. Perfusion and electroencephalogra
TL;DR: The results imply that the disengagement of attention is not selectively disrupted by diazepam, which implies that the increased latencies of saccadic eye movements induced by a low dose ofdiazepam may have practical implications.
Abstract: Effects of the anxiolytic drugs diazepam and buspirone were studied on the reaction time of saccadic eye movements. The study was performed with 8 healthy volunteers in a double-blind, placebo-controlled way. The purpose was to investigate the putative drug effects on the first step of an attention shifting task: the disengagement of attention. Saccadic reaction time was measured in two conditions: the 'gap' and the 'overlap' condition. In the first condition a delay is present between the offset of a fixation spot and the onset of a target, while in the second condition the offset of the spot is overlapped by the onset of the target. Clear differences in saccadic reaction time in the expected direction were found between the two conditions, with longer reaction times of saccadic eye movements in the overlap condition. The nonsedative anxiolytic buspirone in a dose of 5 mg had no significant effects on saccadic reaction times, while clear effects of diazepam in a dose of 5 mg were established. Diazepam slowed down saccadic reaction times, reduced the number of fast saccades and facilitated the number of slow saccades. However, the effects induced by this drug were identical for the two conditions. The latter result implies that the disengagement of attention is not selectively disrupted by diazepam. Perhaps, the action of diazepam is expressed in other attention factors, such as in shifting attention or in the reengagement of attention. A slowing down of these processes by the vigilance-lowering properties of diazepam might be the cause of the prolonged latencies. The increased latencies of saccadic eye movements induced by a low dose of diazepam may have practical implications.
TL;DR: The present results suggest that alterations in serotonergic rather than dopaminergic transmission contribute to the pathophysiology of anxious depression.
Abstract: In a double-blind, placebo-controlled study, the therapeutic efficacy of two antidepressants with different neurochemical mechanisms of action, amitriptyline and amineptine, was investigated in patien
TL;DR: It was found that plasma serine concentrations were significantly higher in depressed subjects than in normal controls, and there were no significant correlations between plasma Serine and postdexamethasone cortisol values.
Abstract: Recently, it has been shown that higher plasma serine concentrations are a possible biological marker for psychoses including schizophrenia. The present study was carried out in order to investigate p
TL;DR: To get a more detailed information on the physiological significance of the EEG complexity measures, the influence of well-known physiological factors was studied in a group of 14 healthy subjects and the differences 'drowsy minus alert' were significantly related to age.
Abstract: In contrast to the single-channel dimensional complexity, the global dimensional complexity is calculated from a multichannel EEG. The intention with the method is to measure the spatial distribution
TL;DR: A number of pieces of evidence are considered which produce problems for the ‘caffeine withdrawal’ explanation of beneficial behavioural effects of caffeine and James rejects such data as reflecting only ‘a small minority of the population’.
Abstract: Caffeine Caffeine withdrawal Psychomotor peformance Andrew P. Smith, Health Psychology Research Unit, Department of Psychology, University of Bristol, 8 Woodland Road, Bristol, BS8 1TN (UK) James [1] has questioned whether the superior performance and increased alertness found in caffeine conditions in a recent series of studies [2-5] were due to actual enhancement by caffeine or merely reflected performance and alertness being degraded by caffeine withdrawal in the two caffeine-free conditions. The present letter to the editor addresses this issue and considers a number of pieces of evidence which produce problems for the ‘caffeine withdrawal’ explanation of beneficial behavioural effects of caffeine. The view that beneficial effects of caffeine reflect degraded performance and alertness in the caffeine-free conditions crucially depends on the strength of the evidence for withdrawal effects. James states that ‘there is an extensive literature showing that caffeine withdrawal has significant adverse effects on human performance and well-being’. If one examines the details of the studies James cites to support this view [6-10] one finds that effects of withdrawal were selective, influencing some functions only, and were not very pronounced. Indeed, these studies provide no evidence that the functions examined in our research are degraded by caffeine withdrawal. Furthermore, even most recent studies of the effects of caffeine withdrawal on performance and well-being [11] can be criticised on methodological grounds (e.g. failing to consider the importance of order of caffeine/placebo conditions). A second point made by James himself in an earlier article [ 12] is that the effects of caffeine on performance and mood are variable and influenced by contextual factors. If withdrawal was the major factor in these studies one should find that, provided enough caffeine was given to prevent withdrawal, further increases in dose should have no effect. This is clearly not the case [13]. Another problem for the ‘caffeine withdrawal’ explanation is that it cannot account for effects in naive users or in animals that have never had caffeine before. Yet behavioural effects clearly occur in these groups and one might expect them to be larger than those found with regular users, where some habituation may take place. James rejects such data as reflecting only ‘a small minority of the population’. Three results from our recent studies also cause problems for the ‘caffeine withdrawal’ explanation. First, it is possible to demonstrate the same effects of caffeine on performance when a person has abstained for only 1 h [14] as when they have had no caffeine for over 12 h [15]. Secondly, level of regular caffeine usage is not correlated with changes in alertness
TL;DR: A standard operating procedure (SOP) for the registration and computer-supported evaluation of pharmaco-EEG data, which is based on published guidelines, and an optimal standard is recommended where appropriate, which functions as a guideline.
Abstract: The working team 'EEG in Phase I' of the Collegium Internationale Psychiatriae Scalarum presents a standard operating procedure (SOP) for the registration and computer-supported evaluation of pharmaco-EEG data, which is based on published guidelines. The minimum standard for recording, amplifying and filtering, validation of hardware and software, artifact treatment and fast Fourier analysis is described in a tabulated from and further explained as accompanying comments. The available SOP can be the basis for the working out of laboratory-specific SOPs. Compliance with the SOP guarantees the possibility of citation by the International Pharmaco-EEG Group (IPEG), Association for Methodology and Documentation in Psychiatry (AMDP), and Collegium Internationale Psychiatriae Scalarum (CIPS). Furthermore, an optimal standard is recommended where appropriate, which functions as a guideline.
TL;DR: In this article, the underlying principles of the different effects of these drugs in healthy volunteers are discussed based on a review of the relevant published data on critical flicker fusion frequency measurements, simple reaction times, complex reaction time, tracking, tapping, and car driving simulation measurements.
Abstract: Nearly all antidepressants are tested psychometrically in order to detect side effects of these drugs. Based on a review of the relevant published data on critical flicker fusion frequency measurements, simple reaction time, complex reaction time, tracking, tapping, and car driving simulation measurements, the underlying principles of the different effects of these drugs in healthy volunteers are discussed. It seems that essentially the sedative properties of a compound are important rather than e.g. specific reuptake inhibiting properties or the chemical structure. This finding is discussed in the light of the usefulness of these test procedures for detecting side effects.
TL;DR: It is suggested that a single treatment with ECS causes a rapid increase in the neuronal 5-HT transporter complex and the increase lasts for 14 days in the frontal cortex.
Abstract: The effects of a single or repeated treatment with electroconvulsive shock (ECS) or imipramine on the central serotonin (5-HT) uptake binding sites were studied in the rat frontal cortex and hippocampus. The selective 5-HT uptake inhibitor citalopram and clomipramine potently inhibited the binding for [3H]paroxetine (5-HT uptake binding sites) in the frontal cortex. The antidepressant drugs imipramine and desipramine inhibited the binding moderately, but the 5-HT-related agents, 5-HT, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), mianserin and ketanserin inhibited it weakly. A single ECS increased the density of [3H]paroxetine binding sites, but did not alter the affinity, after 1 or 24 h, in the frontal cortex. Repeated treatment with ECS, but not with imipramine, increased the density of [3H]paroxetine binding sites in the same region. The hippocampal [3H]paroxetine binding did not change after any of these treatments. These results suggest that a single treatment with ECS causes a rapid increase in the neuronal 5-HT transporter complex and the increase lasts for 14 days in the frontal cortex.
TL;DR: Within the framework of Eysenck's drug postulate alcohol is frequently used as an example for a depressant drug that should shift a person's position on the extraversion-introversion axis in the direc
Abstract: Within the framework of Eysenck’s drug postulate alcohol is frequently used as an example for a depressant drug that should shift a person’s position on the extraversion-introversion axis in the direc