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Biomedical subjects

A B Scholey

Publications and source records attributed to A B Scholey.

At least 19 recordsLinked to original sources
PubMed2006

A double-blind, placebo-controlled, multi-dose evaluation of the acute behavioural effects of guaraná in humans.

The present study aimed to systematically assess acute, dose-related behavioural effects of an extract of guaraná plant for the first time in humans. This double-blind, counterbalanced, placebo-controlled study (n=26) assessed the acute mood and cognitive effects throughout the day of four different doses (37.5 mg, 75 mg, 150 mg and 300 mg) of a standardised guaraná extract (PC-102). Assessment included the Cognitive Drug Research computerized test battery and Bond-Lader mood scales. Guaraná improved secondary memory performance and increased alert and content mood ratings. The two lower doses produced more positive cognitive effects than the higher doses. This research supports previous findings of cognitive improvements following 75 mg guaraná and provides the first exploration of different dose effects of guaraná in humans. The findings suggest that the effects cannot be attributed to caffeine alone.

Administration, Oral↗
PubMed2006

Dancing hot on Ecstasy: physical activity and thermal comfort ratings are associated with the memory and other psychobiological problems reported by recreational MDMA users.

BACKGROUND: Non-drug factors such as ambient temperature can heighten the adverse effects of MDMA (3,4-methylendioxymethamphetamine) in animals. We assessed whether dancing and feeling hot on Ecstasy would be associated with more psychobiological problems in recreational users. METHODS: In an internet study, 206 unpaid participants (modal age 16-24) reported that they had used recreational Ecstasy/MDMA. They completed a drug use questionnaire, the Prospective Memory Questionnaire (PMQ), questions about dancing and feeling hot when on Ecstasy, and psychobiological problems afterwards. RESULTS: Those who danced 'all the time' when on Ecstasy, reported significantly more PMQ memory problems than the less intensive dancers. Prolonged dancing was also associated with more complaints of depression, memory problems, concentration and organizational difficulties afterwards. Feeling hot when on Ecstasy was associated with poor concentration in the comedown period, and with mood fluctuation and impulsivity off-drug. PMQ long-term problems demonstrated a significant curvilinear relationship with thermal self-ratings; more memory problems were noted by those who felt very hot, and by those who did not feel hot when on Ecstasy. CONCLUSIONS: Non-drug factors such as dancing and feeling hot are associated with the incidence of psychobiological problems reported by recreational Ecstasy/MDMA users.

Adolescent↗
PubMed2006

MDMA polydrug users show process-specific central executive impairments coupled with impaired social and emotional judgement processes.

In recent years working memory deficits have been reported in users of MDMA (3,4-methylenedioxymethamphetamine, ecstasy). The current study aimed to assess the impact of MDMA use on three separate central executive processes (set shifting, inhibition and memory updating) and also on "prefrontal" mediated social and emotional judgement processes. Fifteen polydrug ecstasy users and 15 polydrug non-ecstasy user controls completed a general drug use questionnaire, the Brixton Spatial Anticipation task (set shifting), Backward Digit Span procedure (memory updating), Inhibition of Return (inhibition), an emotional intelligence scale, the Tromso Social Intelligence Scale and the Dysexecutive Questionnaire (DEX). Compared with MDMA-free polydrug controls, MDMA polydrug users showed impairments in set shifting and memory updating, and also in social and emotional judgement processes. The latter two deficits remained significant after controlling for other drug use. These data lend further support to the proposal that cognitive processes mediated by the prefrontal cortex may be impaired by recreational ecstasy use.

Adolescent↗
PubMed2006

The glycaemic effects of single doses of Panax ginseng in young healthy volunteers.

The results of two acute placebo-controlled, double-blind cross-over studies assessing the effect of Panax ginseng (G115) on blood glucose levels are reported. In study 1, thirty participants received three treatments: placebo; 200 mg G115; 400 mg G115. In study 2, twenty-seven participants received four treatments: placebo (0 mg ginseng and 30 mg saccharin); ginseng (200 mg ginseng and 30 mg saccharin); placebo-glucose (0 mg ginseng and 25 g oral glucose); ginseng-glucose (200 mg ginseng and 25 g oral glucose). Blood glucose levels were measured at baseline (at 09.00 hours after an overnight fast) and then 60, 90 (study 1 only) and 120 min post-dose. Both studies demonstrated that G115 alone significantly lowers fasting blood glucose levels. Conversely, in study 2 there was a significant drink x ginseng interaction suggesting opposing glycaemic effects of ginseng under fasting and raised blood glucose conditions. These data have implications for the use of ginseng in individuals with poor gluco-regulation.

Adolescent↗
PubMed2005

Differential experiences of the psychobiological sequelae of ecstasy use: quantitative and qualitative data from an internet study.

Previous work provided preliminary evidence that different patterns of use among ecstasy users may impact on perceived side-effects. Participants recruited via an ecstasy-related bulletin board differed in their responses compared to those recruited via other means. The present investigation compares self-reports of psychobiological difficulties among ecstasy users recruited either via a bulletin board or by alternative methods. Qualitative data included reports of any negative or positive changes attributable to ecstasy use and reasons for cessation of use. An Internet-based design was utilized and 209 volunteers completed the study, 117 of whom were recruited via a bulletin board devoted to discussion of ecstasy. Psychobiological difficulties attributable to ecstasy use varied, with mood fluctuation the most common. Differences between the two groups in the extent to which these problems were reported was found. Bulletin board recruits were less likely to report anxiety or poor concentration, but more likely to report tremors/twitches. For the whole sample, lifetime use was associated more with psychobiologial problems, although this pattern was stronger and more pervasive for the non-bulletin board participants. Bulletin board recruits were more aware of possible negative psychological effects and were more likely to report adopting harm reduction strategies. From the qualitative data three negative consequences of use were identified, the most common of which was "psychological problems". In support of the quantitative findings the likelihood of reporting psychological problems increased with lifetime exposure to ecstasy in both recruitment conditions but interestingly this did not appear to impact on reasons for cessation of use. Participants also reported a number of effects that they regarded as beneficial. Future research should also take these aspects of use into account.

Adolescent↗
PubMed2005

Positive modulation of mood and cognitive performance following administration of acute doses of Salvia lavandulaefolia essential oil to healthy young volunteers.

Members of the Sage family, such as Salvia officinalis and Salvia lavandulaefolia, have a long history of use as memory-enhancing agents coupled with cholinergic properties that may potentially be relevant to the amelioration of the cognitive deficits associated with Alzheimer's disease. The current study utilised a placebo-controlled, double-blind, balanced, crossover design in order to comprehensively assess any mood and cognition modulation by S. lavandulaefolia. Twenty-four participants received single doses of placebo, 25 microl and 50 microl of a standardised essential oil of S. lavandulaefolia in an order dictated by a Latin square. Doses were separated by a 7-day washout period. Cognitive performance was assessed prior to the day's treatment and at 1, 2.5, 4 and 6 h thereafter using the Cognitive Drug Research (CDR) computerised test battery. Subjective mood ratings were measured using Bond-Lader visual analogue scales. The primary outcome measures were scores on the five cognitive factors that can be derived by factor analysis of the task outcomes from the CDR battery. The results showed that administration of S. lavandulaefolia resulted in a consistent improvement for both the 25- and 50-microl dose on the 'Speed of Memory' factor. There was also an improvement on the 'Secondary Memory' factor for the 25-microl dose. Mood was consistently enhanced, with increases in self-rated 'alertness', 'calmness' and 'contentedness' following the 50-microl dose and elevated 'calmness' following 25 microl. These results represent further evidence that Salvia is capable of acute modulation of mood and cognition in healthy young adults. The data also suggest that previous reports of memory enhancement by Salvia may be due to more efficient retrieval of target material.

Adolescent↗
PubMed2004

Self-rated everyday and prospective memory abilities of cigarette smokers and non-smokers: a web-based study.

The present study examined self-ratings of two aspects of everyday memory performance: long-term prospective memory-measured by the prospective memory questionnaire (PMQ), and everyday memory-measured by the everyday memory questionnaire (EMQ). Use of other substances was also measured and used as covariates in the study. To ensure confidentiality and to expand the numbers used in previous studies, an Internet study was carried out and data from 763 participants was gathered. After controlling for other drug use and strategy use, the data from the PMQ revealed that smokers reported a greater number of long-term prospective memory errors than non-smokers. There were also differences between light and heavier smokers in long-term prospective memory, suggesting that nicotine may have a dose-dependent impact upon long-term prospective memory performance. There was also a significant ANOVA group effect on the EMQ, although the trend for more memory errors amongst the heavier smokers was statistically only borderline (p=.057). These findings suggest there are selective memory deficits associated with smoking and that long-term prospective memory deficits should be added to the growing list of problems associated with cigarette use.

Adult↗
PubMed2004

Improved cognitive performance in human volunteers following administration of guarana (Paullinia cupana) extract: comparison and interaction with Panax ginseng.

Extracts from the plant guarana (Paullinia cupana) feature as putatively stimulating ingredients in a number of foods, drinks and dietary/herbal supplements. To date, little research in humans has examined the potential psychoactive effects of these extracts. Extracts of Panax ginseng, which are often sold in combination with guarana, contain similar potentially active components, and have been shown to modulate cognitive performance. In this double-blind, counterbalanced, placebo-controlled study, the cognitive and mood effects of separate single doses of: 75 mg of a dried ethanolic extract of guarana (approx 12% caffeine), 200 mg of Panax ginseng (G115), and their combination (75 mg/200 mg), were assessed in 28 healthy young (18-24) participants. On each day of the study (separated by a 7-day washout), cognitive performance and subjective mood were assessed pre-dose and at 1, 2.5, 4 and 6 h post-dose using the Cognitive Drug Research computerised assessment battery, Serial subtraction tasks and Bond-Lader mood scales. In comparison to placebo, all three treatments resulted in improved task performance throughout the day. In the case of guarana, improvements were seen across 'attention' tasks (but with some evidence of reduced accuracy), and on a sentence verification task. While also increasing the speed of attention task performance, both ginseng and the ginseng/guarana combination also enhanced the speed of memory task performance, with little evidence of modulated accuracy. Guarana and the combination, and to a lesser extent ginseng, also led to significant improvements in serial subtraction task performance. These results provide the first demonstration in humans of the psychoactive effects of guarana, and confirmation of the psychoactive properties of ginseng. Given the low caffeine content (9 mg) of this dose of guarana extract, the effects are unlikely to be attributable to its caffeine content.

Adult↗
PubMed2003

Electroencephalograph effects of single doses of Ginkgo biloba and Panax ginseng in healthy young volunteers.

Both Ginkgo biloba and Panax ginseng exert a number of physiological effects and have been shown to modulate aspects of cognitive performance. Whilst a number of studies have examined ginkgo's effects on electroencephalograph (EEG) recordings, to date, none have investigated the EEG effects of ginseng. In this double-blind, placebo-controlled, balanced crossover experiment, the effects of single doses of G. biloba (360 mg GK501), P. ginseng (200 mg G115), and an identical placebo, on auditory-evoked potentials, contingent negative variation (CNV), and resting power within the delta, theta, alpha, and beta wavebands, were assessed in 15 healthy volunteers. Each participant was assessed on three separate occasions 4 h after consuming that day's treatment. The order of presentation of the treatments was dictated by a Latin square with 7 days between testing sessions. The results showed that ginseng led to a significant shortening of the latency of the P300 component of the evoked potential. Both ginseng and ginkgo also led to significant reductions in frontal 'eyes closed' theta and beta activity, with additional reduction for ginseng in the alpha waveband. These findings demonstrate for the first time that P. ginseng can directly modulate cerebroelectrical activity, and that these effects are more pronounced than those following G. biloba.

Adult↗
PubMed2003

Salvia lavandulaefolia (Spanish sage) enhances memory in healthy young volunteers.

Sage (Salvia) has a longstanding reputation in British herbal encyclopaedias as an agent that enhances memory, although there is little evidence regarding the efficacy of sage from systematized trials. Based on known pharmacokinetic and binding properties, it was hypothesised that acute administration of sage would enhance memory in young adult volunteers. Two experiments utilised a placebo-controlled, double-blind, balanced, crossover methodology. In Trial 1, 20 participants received 50, 100 and 150 microl of a standardised essential oil extract of Salvia lavandulaefolia and placebo. In Trial 2, 24 participants received 25 and 50 microl of a standardised essential oil extract of S. lavandulaefolia and placebo. Doses were separated by a 7-day washout period with treatment order determined by Latin squares. Assessment was undertaken using the Cognitive Drug Research computerised test battery prior to treatment and 1, 2.5, 4 and 6 h thereafter. The primary outcome measures were immediate and delayed word recall. The 50 microl dose of Salvia essential oil significantly improved immediate word recall in both studies. These results represent the first systematic evidence that Salvia is capable of acute modulation of cognition in healthy young adults.

Acetylcholinesterase↗
PubMed2003

Modulation of mood and cognitive performance following acute administration of single doses of Melissa officinalis (Lemon balm) with human CNS nicotinic and muscarinic receptor-binding properties.

Melissa officinalis (Lemon balm) is a herbal medicine that has traditionally been attributed with memory-enhancing properties, but which is currently more widely used as a mild sedative and sleep aid. In a previous study it was demonstrated that a commercial Melissa extract led to dose-specific increases in calmness, and dose-dependent decrements in timed memory task performance. However, the extract utilized in that study did not exhibit in vitro cholinergic receptor-binding properties. The current study involved an initial screening of samples of M. officinalis for human acetylcholinesterase inhibition and cholinergic receptor-binding properties. The cognitive and mood effects of single doses of the most cholinergically active dried leaf were then assessed in a randomized, placebo-controlled, double-blind, balanced crossover study. Following the in vitro analysis, 20 healthy, young participants received single doses of 600, 1000, and 1600 mg of encapsulated dried leaf, or a matching placebo, at 7-day intervals. Cognitive performance and mood were assessed predose and at 1, 3, and 6 h postdose using the Cognitive Drug Research computerized assessment battery and Bond-Lader visual analog scales, respectively. In vitro analysis of the chosen extract established IC(50) concentrations of 0.18 and 3.47 mg ml(-1), respectively, for the displacement of [(3)H]-(N)-nicotine and [(3)H]-(N)-scopolamine from nicotinic and muscarinic receptors in the human cerebral cortex tissue. However, no cholinesterase inhibitory properties were detected. The most notable cognitive and mood effects were improved memory performance and increased 'calmness' at all postdose time points for the highest (1600 mg) dose. However, while the profile of results was overwhelmingly favorable for the highest dose, decrements in the speed of timed memory task performance and on a rapid visual information-processing task increased with decreasing dose. These results suggest that doses of Melissa officinalis at or above the maximum employed here can improve cognitive performance and mood and may therefore be a valuable adjunct in the treatment of Alzheimer's disease. The results also suggest that different preparations derived from the same plant species may exhibit different properties depending on the process used for the sample preparation.

Adolescent↗
PubMed2003

Effects of alcohol on subjective ratings of prospective and everyday memory deficits.

BACKGROUND: Research has shown that heavy alcohol use has a detrimental effect on retrospective memory. Less is known about the effect of alcohol on everyday memory. METHODS: This study examined self-ratings of two aspects of memory performance: prospective memory (for example, forgetting to pass on a message) and everyday memory (measured by cognitive failures, such as telling someone a joke that you have told them before). To ensure anonymity and expand on the numbers of participants used in previous studies, data were collected by using the Internet. Data from 763 participants remained after data screening. RESULTS: After controlling for other drug and strategy use, there was clear evidence that differential use of alcohol was associated with impairments in the long-term aspect of prospective memory and with an increased number of cognitive failures. CONCLUSIONS: These results support and extend the findings of previous research: our findings are consistent with the idea that heavy use of alcohol does have a significant and negative effect on everyday cognitive performance. Possible causes of these impairments are discussed.

Adult↗
PubMed2003

Patterns of drug use and the influence of gender on self-reports of memory ability in ecstasy users: a web-based study.

Research indicates that the use of recreational drugs, including MDMA ('ecstasy') can result in impairments in cognitive functioning. Recent evidence, based on accounts of 'on drug' effects and cortical binding ratios suggests that women may be more susceptible to the effects of MDMA; however, no research has explored whether there are differences in the long-term behavioural sequelae of the drug between men and women. In addition, little is known about the profile of functioning of the 'typical' user. The present investigation accessed a large sample of recreational drug users, using the Internet, to obtain self-reports of memory functioning with a view to exploring any differences in self-reported ability amongst male and female users, and the level of difficulty reported by the 'typical' ecstasy user. A web site (www.drugresearch.org.uk) was developed and used for data collection. Prospective memory ability was assessed using the Prospective Memory Questionnaire. Self-report of day-to-day memory performance was investigated using the Everyday Memory Questionnaire. The UEL Drug Questionnaire assessed the use of other substances. The number of mistakes made while completing the questionnaires was also taken as an objective measure of performance errors. Findings, based on datasets submitted from 763 respondents, indicate no differences in self-reports of functioning between male and female participants. An overall dissociation between the effects of cannabis and ecstasy on self-reported memory functioning and on the likelihood of making an error during the completion of the questionnaire was found. Typical ecstasy users were found to report significantly more difficulties in long-term prospective memory and to make more completion errors than users of other substances and drug naive controls. Whilst taking into account the fact that participants were recruited via the World Wide Web and that a number of stringent exclusion criteria were applied to the data, a number of conclusions can be drawn. Recreational drug users perceive their memory ability to be impaired compared to non-users. The type of memory difficulties reported varies depending upon the drug of choice. These difficulties are exacerbated in ecstasy users. Individuals reporting average levels of use of ecstasy are more likely to report memory problems than non-ecstasy drug users or drug free individuals. The deleterious effects of ecstasy are therefore not restricted to heavy or chronic users. No gender differences were detected, suggesting that there may be a dissociation between cognitive impairment and cortical binding worthy of further exploration.

Amphetamine-Related Disorders↗
PubMed2002

Modulation of cognition and mood following administration of single doses of Ginkgo biloba, ginseng, and a ginkgo/ginseng combination to healthy young adults.

It has previously been demonstrated in separate studies that single doses of Ginkgo biloba, Panax ginseng, and a combination of the two extracts can improve different aspects of cognitive performance in healthy young volunteers. The present study directly compared the effects of single doses of G. biloba, ginseng, and a product combining the two on aspects of mood and cognitive performance in the same cohort of healthy, young adult volunteers. The study followed a randomised placebo-controlled, double-blind, balanced, cross-over design. Twenty participants received 360 mg of ginkgo, 400 mg of ginseng, 960 mg of a product combining the two extracts, and a matching placebo. Treatment order was dictated by random allocation to a Latin square, with a 7-day wash-out period between treatments. Cognitive testing comprised completion of the Cognitive Drug Research (CDR) computerised assessment battery and two serial subtraction mental arithmetic tasks. Mood was assessed with Bond-Lader visual analogue scales. Following a baseline cognitive assessment, further test sessions took place 1, 2.5, 4, and 6 h after the day's treatment was taken. The results largely supported previous findings. All three treatments were associated with improved secondary memory performance on the CDR battery, with the ginseng condition evincing some improvement in the speed of performing memory tasks and in the accuracy of attentional tasks. Following ginkgo and the ginkgo/ginseng combination performance of both the Serial Threes and Serial Sevens, subtraction tasks was also improved at the later testing sessions. No modulation of the speed of performing attention tasks was evident. Improvements in self-rated mood was also found following ginkgo and to a lesser extent the combination product.

Adolescent↗
PubMed2002

Ecstasy/MDMA attributed problems reported by novice, moderate and heavy recreational users.

RATIONALE: The recreational use of MDMA/Ecstasy (3,4-methylenedioxymethamphetamine) is associated with many psychobiological problems, but there is a paucity of data on how these relate to the level of past use. OBJECTIVES: to assess the incidence of Ecstasy-attributed problems as reported by novice, moderate and heavy users. METHODS: 763 unpaid volunteers took part in a WWW study of recreational drug use. This report is based on the 282 Ecstasy users from that sample, who comprised 109 novice users (1-9 occasions), 136 moderate users (10-99 occasions), and 36 heavy users (+100 occasions). Yes/no responses were automatically recorded to a series of questions covering psychobiological problems experienced when drug-free, which were attributed by the respondents to their Ecstasy use. RESULTS: Depression, memory problems, anxiety, mood fluctuation, poor concentration, infections, tremors/twitches and weight loss, were all significantly associated with the extent of Ecstasy use. Thus memory problems attributed to Ecstasy were reported by 19% of novice users, 52% of heavy users and 73% of heavy users (chi-square 42.74, df=2, p<0.001); many of the other variables showed similar trends. CONCLUSIONS: The incidence of problems attributed to Ecstasy use, is directly related to the number of occasions it has been used.

Anxiety↗
PubMed2002

Validation of a telephone cognitive assessment test battery for use in chronic fatigue syndrome.

We compared a computerized version of the Cognitive Drug Research (CDR) cognitive assessment test battery and a completely automated telephone version of the same battery. These assessed aspects of attention, working memory and long-term memory. Both methods were used to assess the cognitive performance of a cohort of 30 people with confirmed chronic fatigue syndrome (CFS) and a group of 30 healthy controls matched for age and education. The CFS group had significantly slower reaction times on all four cognitive measures on both the computerized and telephone tests. The mood data followed similar patterns inthe computer and telephone assessments. The results from both forms of the test battery confirmed the pattern and severity of cognitive impairment in CFS. Furthermore, the two methods of testing were similarly sensitive in detecting cognitive deficits. The incapacitating nature of CFS may cause problems for researchers if the restrictions to mobility affect the representativeness of the study group. The findings of the present study support the use of a fully automated telephone cognitive testing system for detecting deficits in CFS.

Attention↗