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Keith A Wesnes

Publications and source records attributed to Keith A Wesnes.

At least 19 recordsLinked to original sources

A low glycaemic index breakfast cereal preferentially prevents children's cognitive performance from declining throughout the morning.

This study investigated whether the glycaemic index (GI) of breakfast cereal differentially affects children's attention and memory. Using a balanced cross-over design, on two consecutive mornings 64 children aged 6-11 years were given a high GI cereal and a low GI cereal in a counterbalanced order. They performed a series of computerised tests of attention and memory, once prior to breakfast and three times following breakfast at hourly intervals. The results indicate that children's performance declines throughout the morning and that this decline can be significantly reduced following the intake of a low GI cereal as compared with a high GI cereal on measures of accuracy of attention (M=-6.742 and -13.510, respectively, p<0.05) and secondary memory (M=-30.675 and -47.183, respectively, p<0.05).

Attention↗

Orthostatic hypotension in Parkinson's disease: association with cognitive decline?

BACKGROUND: Orthostatic hypotension is common in Lewy body disorders and may be related to disease progression and the spread of Lewy body pathology. We therefore hypothesize that PD patients with orthostatic hypotension (OH) have a different cognitive profile compared to PD patients without OH. METHODS: This cross-sectional study included 175 PD patients. Blood pressure (BP) was measured with a validated digital blood pressure monitor and patients with a systolic BP drop of > or =20 mmHg or a systolic pressure of <90 mm Hg after standing were considered to have OH. Cognition was assessed using MMSE extended by a selection of computerized cognitive tests focusing on reaction time, sustained attention, working memory and episodic verbal and visual memory. RESULTS: Eighty-seven (49.7%) of the PD patients had OH. These patients were significantly more impaired in sustained attention and visual episodic memory compared to PD patients without OH. CONCLUSION: We conclude that there are differences in the neuropsychological performance of patients with PD and OH, supporting the hypothesis that OH might be a marker for disease progression and cognitive decline in PD.

Aged↗

Effects of armodafinil in the treatment of residual excessive sleepiness associated with obstructive sleep apnea/hypopnea syndrome: a 12-week, multicenter, double-blind, randomized, placebo-controlled study in nCPAP-adherent adults.

BACKGROUND: Some patients with obstructive sleep apnea/hypopnea syndrome (OSA/HS) experience excessive sleepiness (ES) that might not resolve with nasal continuous positive airway pressure (nCPAP) treatment. OBJECTIVE: The aim of the present study was to assess the efficacy and tolerability of armodafinil 150 or 250 mg QD when used as adjunctive treatment for residual ES associated with OSA/HS in patients who are adherent to nCPAP therapy. METHODS: This 12-week, multicenter, double-blind, randomized, placebo-controlled study was conducted at 37 centers in the United States and Canada. Male and female patients aged 18 to 65 years with residual ES associated with OSA/HS were enrolled. Patients were randomly assigned to receive armodafinil 150 or 250 mg or placebo PO QD for 12 weeks. Assessments were conducted at baseline and study weeks 4, 8, and 12 and included the Maintenance of Wakefulness Test (MWT) to determine wakefulness, the Clinical Global Impression of Change (CGI-C) to determine improvement in clinical condition, the Epworth Sleepiness Scale (ESS) to determine patient-estimated wakefulness, the Brief Fatigue Inventory (BFI) to determine global fatigue, and the Cognitive Drug Research computerized assessment battery. To distinguish between earlier and later effects, sleep latencies, assessed using the MWT, were averaged across the first 4 (9 and 11 AM, and 1 and 3 PM) and last 3 (3, 5, and 7 PM) tests. Tolerability assessments included monitoring of adverse events (AEs), clinical laboratory tests, vital sign measurements, and electrocardiography. RESULTS: A total of 395 patients were enrolled in the study (armodafinil 150 mg/d, 133; armodafinil 250 mg/d, 131; placebo, 131); 392 received >or=1 dose of study drug (armodafinil 150 mg/d, 131; armodafinil 250 mg/d, 131; placebo, 130). The armodafinil and placebo groups were well matched with regard to age (mean [SD], 49.2 [8.9] vs 50.1 [9.4] years), sex (71 vs 69% men), race (84% vs 87% white), and body weight (mean [SD], 110.3 [24.9] vs 111.9 [24.0] kg). At the final visit, the mean (SD) change from baseline in MWT sleep latency across the morning and afternoon was significantly greater in the armodafinil combined group compared with the placebo group (+1.9 [7.3] vs 1.7 [8.6] minutes; P < 0.001). Also at the final visit, the proportions of patients who showed at least minimal improvement on the CGI-C, and the mean (SD) changes from baseline in ESS and BFI scores, were significantly greater in the armodafinil group compared with those in the placebo group (72% vs 37%, -5.5 [5.0] vs -3.3 [4.7], and -1.2 [2.2] vs -0.6 [2.0], respectively; P < 0.001, P < 0.001, and P < 0.01, respectively). No significant effects on nighttime sleep, as assessed using polysomnography, were found with armodafinil. AEs reported in the armodafinil combined and placebo groups were headache, nausea, insomnia, anxiety, and dizziness. Serious AEs (ulcerative colitis, migraine, worsening of Axis II and mood disorder, and duodenal ulcer) were reported in 4 (1.5%) patients receiving armodafinil and were considered by the investigator not or unlikely to be drug related. CONCLUSIONS: In this selected population of patients with OSA/HS and residual ES despite effective treatment with nCPAP, armodafinil QD used as an adjunct to nCPAP treatment was associated with improved wakefulness and overall clinical condition. Clinical benefit was shown at the first assessment and maintained for the 12-week duration of the study. Armodafinil was also associated with significantly reduced interference of ES with daily activities and global fatigue. Armodafinil was well tolerated, with no adverse effect on nighttime sleep or nCPAP use.

Benzhydryl Compounds↗

Effects of food on the single-dose pharmacokinetics/pharmacodynamics of tizanidine capsules and tablets in healthy volunteers.

BACKGROUND: A multiparticulate capsule formulation of the alpha2-adrenergic agonist tizanidine has been developed to decrease C(max), AUC, and associated somnolence, while maintaining efficacy. OBJECTIVE: The purpose of this study was to compare the pharmacokinetics and impact of somnolence on cognitive function after single doses of the tablet and capsule formulations of tizanidine under fed and fasted conditions in healthy volunteers. METHODS: This Phase I, single-dose, randomized, open-label, 4-way crossover study was conducted at MDS Pharma Services, Belfast, United Kingdom. Healthy male and female adult subjects received tizanidine (8 mg) as tablets and capsules under fasting and nonfasting conditions. Blood samples were collected to determine plasma tizanidine pharmacokinetic profiles, and computerized cognitive function tests were performed that yielded a validated composite score, Power of Attention, an index of sedation. RESULTS: Ninety-six patients were enrolled in the study (54 men, 42 women; mean [SD] age, 27 [8] years [range, 18-52 years]; mean [SD] body weight, 71.7 [12.4] kg [range, 46-102 kg]). Tizanidine tablets and capsules were found to be bioequivalent after fasting. In the fed state, mean C(max) and AUC(0-t) were substantially decreased, by 33.8% and 15.4%, comparing the capsules and tablets, respectively. The median T(max) increased significantly from 1.41 to 3.0 hours (P < 0.001). Administration of the capsules with food resulted in <20% difference in mean C(max) and AUC(0-t) compared with the fasting state, whereas mean C(max) and AUC(0-t) were 22.6% and 45.2% higher when the tablet formulation was administered with food. The onset of impairment in Power of Attention was significantly delayed from 0.75 to 1.5 hours postdose when capsules were administered with food compared with the other conditions (P < 0.001). The most commonly reported adverse events were asthenia, somnolence, and orthostatic hypotension. A significantly lower adverse event rate was observed in the combined capsules group compared with the tablets, suggesting that differences in tolerability may exist. CONCLUSIONS: The results of this study in healthy volunteers suggest that the capsule and tablet formulations of tizanidine were bioequivalent only in the fasted state. The capsule formulation exhibited a food effect that reduced C(max) and AUC(0-t), and significantly increased T(max), which was associated with a delay in cognitive impairment. The large interpatient variability in plasma profiles most likely dampened the ability to fully elucidate the differences between the 2 formulations.

Adolescent↗

The efficacy and safety of armodafinil as treatment for adults with excessive sleepiness associated with narcolepsy.

OBJECTIVE: This study assessed the efficacy and safety of armodafinil, the longer half-life enantiomer of modafinil, for the treatment of excessive sleepiness in patients with narcolepsy. RESEARCH DESIGN AND METHODS: This was a multicenter double-blind study with 196 patients (aged 18-65 years) randomized to receive armodafinil 150 mg (n = 65), armodafinil 250 mg (n = 67), or placebo (n = 64) once daily for 12 weeks. MAIN OUTCOME MEASURES: Efficacy was assessed using the Maintenance of Wakefulness Test (MWT) (six 20-min subtests across the day), the Clinical Global Impression of Change (CGI-C), subjective measures of sleepiness (Epworth Sleepiness Scale), patient diaries, and evaluations of cognitive performance (Cognitive Drug Research) and fatigue (Brief Fatigue Inventory). RESULTS: Armodafinil significantly increased MWT mean sleep latency (at 0900-1500) compared with placebo. The mean change from baseline at final visit for armodafinil was an increase of 1.3, 2.6, and 1.9 min in the 150-mg, 250-mg, and combined groups, respectively, compared with a decrease of 1.9 min for placebo (p < 0.01 for all three comparisons). Mean late-day MWT latency (1500-1900) was also significantly improved (difference of armodafinil combined group relative to placebo at final visit: 2.8 min, p = 0.0358). The proportions of patients who showed at least minimal improvement in the CGIC rating from baseline to final visit in the armodafinil 150-mg, 250-mg, and combined groups were 69%, 73%, and 71%, respectively, compared with 33% for placebo (p < 0.0001). Both doses were associated with statistically significant improvements in memory, attention, and fatigue (p < 0.05). The most common adverse events in patients receiving armodafinil were headache, nausea, and dizziness. CONCLUSIONS: Armodafinil significantly improved ability to sustain wakefulness throughout the day in patients with narcolepsy. Armodafinil also significantly improved overall clinical condition, memory, attention, and fatigue when compared with placebo.

Adolescent↗

Cognitive function testing: the case for standardization and automation.

This review considers the advantages that both standardization and automation of cognitive function testing can bring to clinical research. It reviews progress made in several fields of medicine with a standardized and automated cognitive function assessment system which has been in use in worldwide clinical trials for over 20 years. Data are presented showing the effects on cognitive function of both normal ageing and a variety of diseases. The utility of cognitive testing in the identification and classification of dementia is considered, and its ability to further our understanding of the cognitive sequelae of stroke is discussed. The correlation between assessments of cognitive function and patients' ability to undertake the activities of daily living is evaluated. Finally, the use of such techniques to identify beneficial effects of treatment in various conditions is described. The review concludes that standardization and automation of cognitive function testing have facilitated progress in a number of fields, and that the systematic application of such a technique in menopause research would greatly help advance our knowledge in this field.

Activities of Daily Living↗

Combined D1/D2 receptor stimulation under conditions of dopamine depletion impairs spatial working memory performance in humans.

RATIONALE: The mesocortical dopamine system is regarded as an important modulator of working memory. While it has been established that stimulation of the D1/D2 receptor in primates can improve spatial working memory performance, findings in humans are less consistent. Recent studies in humans suggest that global depletion of dopamine via tyrosine/phenylalanine depletion may impair spatial working memory performance, although these results are also inconsistent, and it has been suggested that task differences may partly underlie the inconsistent findings. OBJECTIVES: This study had two aims: (1) to investigate the effects of acute tyrosine depletion (TPD) on a number of working memory tasks and (2) to examine whether stimulation of D1/D2 receptors under conditions of TPD can attenuate or "reverse" TPD-induced working memory impairments. METHODS: Eighteen healthy male participants performed a spatial working memory delayed-recognition task, non-spatial working memory task and spatial n-back task on three separate occasions, after TPD, TPD and pergolide (D1/D2 agonist), and placebo. RESULTS: TPD did not impair working memory performance on any of the tasks administered. However, stimulation of D1/D2 receptors under TPD conditions caused a subtle impairment in spatial working memory performance. CONCLUSIONS: The finding that D1/D2 stimulation under TPD conditions impairs working memory highlights the complexity of functional effects of augmenting dopaminergic transmission within a dopamine-depleted state. The lack of TPD-related effects on a range of working memory tasks questions the reliability of TPD as a modulator of dopamine function and working memory performance in humans.

Adolescent↗

Muscarinic and nicotinic receptors synergistically modulate working memory and attention in humans.

Functional abnormalities in muscarinic and nicotinic receptors are associated with a number of disorders including Alzheimer's disease and schizophrenia. While the contribution of muscarinic receptors in modulating cognition is well established in humans, the effects of nicotinic receptors and the interactions and possible synergistic effects between muscarinic and nicotinic receptors have not been well characterized in humans. The current study examined the effects of selective and simultaneous muscarinic and nicotinic receptor antagonism on a range of cognitive processes. The study was a double-blind, placebo-controlled, repeated measures design in which 12 healthy, young volunteers completed cognitive testing under four acute treatment conditions: placebo (P); mecamylamine (15 mg) (M); scopolamine (0.4 mg i.m.) (S); mecamylamine (15 mg)/scopolamine (0.4 mg i.m.) (MS). Muscarinic receptor antagonism with scopolamine resulted in deficits in working memory, declarative memory, sustained visual attention and psychomotor speed. Nicotinic antagonism with mecamylamine had no effect on any of the cognitive processes examined. Simultaneous antagonism of both muscarinic and nicotinic receptors with mecamylamine and scopolamine impaired all cognitive processes impaired by scopolamine and produced greater deficits than either muscarinic or nicotinic blockade alone, particularly on working memory, visual attention and psychomotor speed. These findings suggest that muscarinic and nicotinic receptors may interact functionally to have synergistic effects particularly on working memory and attention and suggests that therapeutic strategies targeting both receptor systems may be useful in improving selective cognitive processes in a number of disorders.

Adult↗

Cognitive and mood improvements of caffeine in habitual consumers and habitual non-consumers of caffeine.

RATIONALE: The cognitive and mood effects of caffeine are well documented. However, the majority of studies in this area involve caffeine-deprived, habitual caffeine users. It is therefore unclear whether any beneficial findings are due to the positive effects of caffeine or to the alleviation of caffeine withdrawal. OBJECTIVES: The present placebo-controlled, double-blind, balanced crossover study investigated the acute cognitive and mood effects of caffeine in habitual users and habitual non-users of caffeine. METHOD: Following overnight caffeine withdrawal, 24 habitual caffeine consumers (mean=217 mg/day) and 24 habitual non-consumers (20 mg/day) received a 150 ml drink containing either 75 or 150 mg of caffeine or a matching placebo, at intervals of > or =48 h. Cognitive and mood assessments were undertaken at baseline and 30 min post-drink. These included the Cognitive Drug Research computerised test battery, two serial subtraction tasks, a sentence verification task and subjective visual analogue mood scales. RESULTS: There were no baseline differences between the groups' mood or performance. Following caffeine, there were significant improvements in simple reaction time, digit vigilance reaction time, numeric working memory reaction time and sentence verification accuracy, irrespective of group. Self-rated mental fatigue was reduced and ratings of alertness were significantly improved by caffeine independent of group. There were also group effects for rapid visual information processing false alarms and spatial memory accuracy with habitual consumers outperforming non-consumers. There was a single significant interaction of group and treatment effects on jittery ratings. Separate analyses of each groups' responses to caffeine revealed overlapping but differential responses to caffeine. Caffeine tended to benefit consumers' mood more while improving performance more in the non-consumers. CONCLUSIONS: These results do not support a withdrawal alleviation model. Differences in the patterns of responses to caffeine by habitual consumers and habitual non-consumers may go some way to explaining why some individuals become caffeine consumers.

Adolescent↗

Pharmacodynamic effects of darifenacin, a muscarinic M selective receptor antagonist for the treatment of overactive bladder, in healthy volunteers.

OBJECTIVE: To evaluate the pharmacodynamic effects of darifenacin (a muscarinic M(3) selective receptor antagonist) and dicyclomine (an M(1) selective receptor antagonist) in healthy male volunteers. SUBJECTS AND METHODS: In this double-blind, four-way crossover study, 27 healthy men (aged 19-44 years) were randomized to receive darifenacin 7.5 mg or 15 mg once daily, dicyclomine 20 mg four times daily or matching placebo. Each 7-day treatment period was separated by a 7-day washout. Multiple assessments of cognitive function, quantitative electroencephalogram (EEG) recordings, salivation, visual nearpoint, heart rate and heart rate variability were made on day 7 in each treatment period. RESULTS: Compared with placebo, neither dose of darifenacin affected cognitive function, whereas dicyclomine impaired performance on five of the 12 variables 2 h after dosing; simple reaction time (P = 0.009), speed of numeric (P = 0.012) and spatial (P = 0.048) working memory, and speed (P = 0.04) and sensitivity (P = 0.03) of picture recognition. These cognitive changes were accompanied by slowing of the EEG for dicyclomine. Darifenacin showed no clinically relevant effect on EEG. Darifenacin 7.5 and 15 mg once daily did not differ from placebo in effects on visual nearpoint, heart rate or heart rate variability. By contrast, dicyclomine significantly increased the maximum visual nearpoint, decreased heart rate and increased heart rate variability, relative to placebo. Both agents decreased salivary flow rate vs placebo. Treatment-related adverse events were comparable in all groups, the most common being dry mouth; none led to treatment discontinuation. CONCLUSIONS: Darifenacin did not affect cognitive, cardiac or visual function in healthy volunteers, a profile that may reflect its relative M(3) receptor selectivity and M(1)/M(2) sparing properties.

Adult↗

Short-term transdermal estradiol therapy, cognition and depressive symptoms in healthy older women. A randomised placebo controlled pilot cross-over study.

The potential role of estrogen in protecting women from cognitive decline and reducing depressive symptoms is of great therapeutic interest. In a pilot randomised placebo controlled cross-over study, we aimed to determine the short-term effects of transdermal estradiol therapy on cognition and depressive symptoms in healthy cognitively normal post-menopausal women over 60 years of age. Nineteen cognitively normal women, without clinical depression whom had undergone a hysterectomy in the past were recruited. Women were randomised to receive either transdermal estradiol 50 microg/24 h (Femseven) or transdermal placebo for 12 weeks before crossing over to the other medication for a further 12 weeks. Cognition was assessed every 6 weeks by the cognitive drug research (CDR) computerised assessment which recorded both accuracy and speed in the following cognitive tests; simple reaction time, choice reaction time, digit vigilance, visual tracking, spatial working memory, immediate and delayed word recall and delayed face and picture recall. Depressive symptoms were measured using the brief assessment scale depression card (BASDEC) depression rating scale at baseline, 12 and 24 weeks. Participants had a mean age of 71, IQ of 115 and MMSE of 29. Simple reaction time and the BASDEC depression rating scale improved after 12 weeks of estradiol use. All other tests were unaltered by estradiol. Twelve weeks of transdermal estradiol therapy did not consistently improve the speed or accuracy of older women in various cognitive tests. However, the results do support the concept that depressive symptoms may be reduced by estradiol, and not simply due to the relief of climacteric symptoms.

Administration, Cutaneous↗

Effect of galantamine hydrobromide in chronic fatigue syndrome: a randomized controlled trial.

CONTEXT: There is no established pharmacological treatment for the core symptoms of chronic fatigue syndrome (CFS). Galantamine hydrobromide, an acetyl cholesterone inhibitor, has pharmacological properties that might benefit patients with CFS. OBJECTIVE: To compare the efficacy and tolerability of galantamine hydrobromide in patients with CFS. DESIGN, SETTING, AND PATIENTS: Randomized, double-blind trial conducted June 1997 through July 1999 at 35 outpatient centers in the United Kingdom (n = 17), United States (n = 14), the Netherlands (n = 2), Sweden (n = 1), and Belgium (n = 1) involving 434 patients with a clinical diagnosis of CFS (modified US Centers for Disease Control and Prevention criteria). INTERVENTIONS: A total of 89 patients were randomly assigned to receive 2.5 mg of galantamine hydrobromide; 86 patients, 5.0 mg; 91 patients, 7.5 mg; and 86 patients, 10 mg (these patients received medicine in the tablet form 3 times per day); a total of 82 patients received matching placebo tablets 3 times per day. MAIN OUTCOME MEASURES: The primary efficacy variable was the global change on the Clinician Global Impression Scale after 4, 8, 12, and 16 weeks of treatment. Secondary outcomes were changes in core symptoms of CFS on the Chalder Fatigue Rating Scale, the Fibromyalgia Impact Questionnaire, and the Pittsburgh Sleep Quality Index; changes in quality of life on the Nottingham Health Profile; and assessment of plasma-free cortisol levels and cognitive performance on a computer-based battery of tests. RESULTS: After 16 weeks, there were no statistically significant differences between any of the galantamine or placebo groups in clinical condition on the Clinician Global Impression Scale, or for any of the secondary end points. Exploratory regression analysis failed to detect any consistent prognostic factor that might have influenced the primary or any secondary outcome measures. CONCLUSION: This trial did not demonstrate any benefit of galantamine over placebo in the treatment of patients with CFS.

Adult↗

Hallucinations predict attentional improvements with rivastigmine in dementia with lewy bodies.

The aim of this analysis of the effects of cholinergic therapy in dementia with Lewy bodies was to determine whether rivastigmine-induced benefits in attention and memory could be predicted by the presence of visual hallucinations. At study entry, 74% of patients were hallucinators and 26% were non-hallucinators. The population was analyzed for two-factor scores: power of attention (PoA) and quality of memory (QoM). A significant effect over placebo on PoA was observed in hallucinators at weeks 12 (p = 0.023) and 20 (p = 0.0019), while no treatment effects were seen in non-hallucinators. Significant treatment effects on QoM were not observed in either subgroup. Visual hallucinations predicted greater improvements in PoA, but not QoM. This may reflect the greater cholinergic deficits in areas of the brain responsible for visual hallucinations, offering greater potential for attentional improvement.

Aged↗

Baseline plasma GABA: its relationship to the adverse effects of acute lorazepam administration on cognition in the elderly.

The GABA system is an active target for drugs to treat a variety of disorders and the availability of an indirect measure of central GABA activity would not only enhance psychiatric research, but also permit assessment of the pharmacodynamic effects of drugs designed to act on this system. The relationships between plasma baseline pre-drug GABA concentrations and cognitive impairments induced by an acute oral dose of lorazepam (0.5 and 1.0 mg) were investigated in 22 healthy elderly individuals. Partial correlations controlling for plasma lorazepam concentrations revealed no significant relationship between baseline plasma GABA levels and lorazepam-induced impairments on tests of cognitive functioning. Plasma GABA concentration does not appear to be a useful marker of susceptibility to benzodiazepine-induced cognitive toxicity in the elderly. Other approaches to estimating central GABA activity should be pursued.

Affect↗

Simultaneous depletion of serotonin and catecholamines impairs sustained attention in healthy female subjects without affecting learning and memory.

Monoamine neurotransmitters, serotonin, noradrenaline and dopamine modulate many important cognitive processes such as attention, learning and memory. While the selective effects of serotonin and catecholamine depletion on such processes have been investigated, the effects of simultaneous depletion of these monoamines on cognition remain unclear. This is of particular interest given that multiple neurotransmitter abnormalities have been implicated in many psychiatric disorders. The aim of the current study was to examine the effects of lowered brain monoamine function on cognitive performance, using the technique of amino acid precursor depletion. The study was a double-blind, placebo-controlled design in which 20 healthy female subjects were tested under a combined monoamine depletion condition (CMD) and a balanced control condition (B). Cognitive testing was conducted at baseline and 5 h post-depletion. The CMD condition relative to the B condition resulted in deficits in digit vigilance (accuracy and reaction time), a measure of sustained attention. There were no effects on measures of learning and memory or psychomotor function. These findings suggest that simultaneously depleting the availability of brain serotonin and catecholamines in healthy female subjects selectively impairs sustained attention, without affecting other cognitive domains.

Adolescent↗

Selective effects of acute serotonin and catecholamine depletion on memory in healthy women.

There is converging evidence that brain serotonin and dopamine may selectively modulate learning and memory in humans. However, this has not been directly demonstrated. In the current study, we used the method of amino acid precursor depletion to explore the effects of low serotonin and catecholamine function on memory in healthy female volunteers. Participants completed three experimental sessions: (i) tryptophan depletion (TD to lower 5-HT); (ii) tyrosine and phenylalanine depletion (TPD to lower catecholamines); and (iii) a balanced control condition (Bal). All testing was conducted in a double-blind, placebo-controlled, crossover design. Cognitive and mood assessments were performed at baseline and 5 h after ingesting the amino acid mixture. Consistent with previous studies, TD impaired declarative memory consolidation on a structured word-learning task, while TPD, acting to lower brain dopamine availability, impaired spatial working memory. No secondary deficits were observed on measures of attention, short-term memory or subjective mood state. These findings suggest that low brain serotonin versus dopamine selectively impairs memory performance in humans. This may shed light on the role of these neurotransmitters in disorders that are characterized by significant memory impairment.

Adult↗

Breakfast reduces declines in attention and memory over the morning in schoolchildren.

Twenty-nine schoolchildren were tested throughout the morning on 4 successive days, having a different breakfast each day (either of the cereals Cheerios or Shreddies, glucose drink or No breakfast). A series of computerised tests of attention, working memory and episodic secondary memory was conducted prior to breakfast and again 30, 90, 150 and 210 min later. The glucose drink and No breakfast conditions were followed by declines in attention and memory, but the declines were significantly reduced in the two cereal conditions. This study provides objective evidence that a typical breakfast of cereal rich in complex carbohydrates can help maintain mental performance over the morning.

Adolescent↗

Reboxetine versus paroxetine versus placebo: effects on cognitive functioning in depressed patients.

Impaired cognitive functioning is often associated with major depressive disorder (MDD). Moreover, a number of agents used to treat MDD are known to have negative effects on cognitive functioning. We report an assessment of the effects of the selective norepinephrine reuptake inhibitor reboxetine, the selective serotonin reuptake inhibitor paroxetine, and placebo on a variety of measures of cognitive functioning in patients with MDD. Cognitive functioning in 74 adult patients (aged 18-65 years) with a confirmed diagnosis of MDD (DSM-IV) was assessed as part of two identical, randomized, double-blind, placebo- and active-treatment-controlled, fixed/flexible dose comparisons of 8 weeks of treatment with reboxetine (8-10 mg/day), paroxetine (20-40 mg/day) and placebo. Cognitive function was assessed at baseline, day 14 and day 56 using a selection of tasks from the Cognitive Drug Research computerized assessment system, including Simple Reaction Time, Digit Vigilance, Choice Reaction Time, Numeric Working Memory, Word Recognition and Critical Flicker Frequency. The results in the 74 patients (reboxetine n = 25, paroxetine n = 23, placebo n = 26) showed that reboxetine significantly improved the ability to sustain attention at day 56 compared with baseline (P = 0.023). In addition, patients who received reboxetine experienced significant improvements in their speed of cognitive functioning when tested at day 56 compared to baseline (P = 0.024). No significant changes or trends in this direction were seen among patients who received either placebo or paroxetine. The results of the present study provide objective data to support the possibility that reboxetine favourably affects cognitive processes in depressed patients.

Adolescent↗