The Dynamic Relationship between the Glymphatic System, Aging, Memory, and Sleep.

The process of memory entails the activation of numerous neural networks and biochemical pathways throughout the brain. The phenomenon of memory decline in relation to aging has been the subject of extensive research for several decades. The correlation between the process of aging and memory is intricate and has various aspects to consider. Throughout the aging process, there are various alterations that take place within the brain and, as expected, affect other functions that have already been linked to memory and its function such as involving microcirculation and sleep. Recent studies provide an understanding of how these mechanisms may be interconnected through the relatively new concept of the glymphatic system. The glymphatic system is strongly correlated to sleep processes. Sleep helps the glymphatic system remove brain waste solutes. Astrocytes expand and contract to form channels for cerebrospinal fluid (CSF) to wash through the brain and eliminate waste. However, the details have not been totally elusive, but the discovery of what we call the glymphatic system enables us to connect many pieces of physiology to understand how such factors are interconnected and the interplay between them. Thus, the purpose of this review is to discuss how the glymphatic system, sleep, memory, and aging are interconnected through a network of complex mechanisms and dynamic interactions.

Determinants of completion and early dropout in an adult weight management service: a prospective observational study.

BACKGROUND: High attrition rates in weight management interventions (WMIs) undermine their effectiveness but are poorly understood. This study aimed to identify determinants of completion and early dropout in National Health Service (NHS) WMIs. METHODS: In this prospective observational study, 329 patients recruited at initial consultation appointments satisfied the eligibility criteria: age ≥18 years and body mass index (BMI) ≥30 kg/m2 . Multivariate logistic regression analyses were performed to identify the odds ratios (OR, given with 95% confidence interval) of completion and early dropout. RESULTS: Intervention completion rate was 39.8% (131 of 329). Variables that increased the likelihood of completion included engagement in support sessions, OR10.6 (4.7-23.6, p < 0.001); male sex, OR2.5 (1.4-4.5, p = 0.002); osteoarthritis, OR1.9 (1.1-3.3, p = 0.014); and one or more missed intervention appointments marked as 'could not attend' (notified nonattendance), OR1.8 (1.1-2.9, p = 0.032). Odds of early dropout were higher for participants with anxiety and depression OR2.0 (1.0-4.0, p = 0.039). Dietetic 1:1 participants were less likely to drop out early compared with group programme participants, OR0.3 (0.2-0.7, p = 0.002), but were less likely to complete the full intervention, OR0.5 (0.3-0.9, p = 0.02). Age, BMI, social deprivation and travel distance were among the variables not associated with completion or early dropout. CONCLUSIONS: This study provides further evidence of the importance of support for participants of WMIs and the need for services to consider how support networks can be incorporated. Patients with poorer mental health may be more likely to drop out early and consequently benefit less from WMIs. Future research should qualitatively explore why these factors contribute to attrition to improve WMI effectiveness.

Development of a Positive Psychology Well-Being Intervention in a Community Pharmacy Setting.

Background: Community pharmacies are well-placed to deliver well-being interventions; however, to date, nothing has been produced specifically for this setting. The aim of this study was to develop a positive psychology intervention suitable for a community pharmacy setting with the goal of increasing the well-being of community members. Methods: Intervention development consisted of three steps: Step 1-identify the evidence-base and well-being model to underpin the basis of the intervention (Version 1); Step 2-model the intervention and gather user feedback to produce Version 2, and Step 3-revisit the evidence-base and refine the intervention to produce Version 3. Results: Findings from nine studies (seven RCTs, one cross-sectional, one N-1 design plus user feedback were applied to model a 6-week 'Prescribing Happiness (P-Hap)' intervention, underpinned by the PERMA model plus four other components from the positive psychology literature (Three Good Things, Utilising Your Signature Strengths in New Ways, Best Possible Selves and Character Strengths). A PERMA-based diary was designed to be completed 3 days a week as part of the intervention. Conclusions: This work is an important development which will direct the future implementation of interventions to support well-being in this novel setting. The next stage is to gain the perspectives of external stakeholders on the feasibility of delivering the P-Hap for its adoption into community pharmacy services in the future.

External validity and anchoring heuristics: application of DUNDRUM-1 to secure service gatekeeping in South Wales.

Aims and method Structured clinical judgement tools provide scope for the standardisation of forensic service gatekeeping and also allow identification of heuristics in this decision process. The DUNDRUM-1 triage tool was completed retrospectively for 121 first-time referrals to forensic services in South Wales. Fifty were admitted to medium security, 49 to low security and 22 remained in open conditions. RESULTS: DUNDRUM-1 total scores differed appropriately between different levels of security. However, regression revealed heuristic anchoring on the 'legal process' and 'immediacy of risk due to mental disorder' items. Clinical implications Patient placement was broadly aligned with DUNDRUM-1 recommendations. However, not all triage items informed gatekeeping decisions. It remains to be seen whether decisions anchored in this way are effective. Declaration of interest Dr Mark Freestone gave permission for AUC values from Freestone et al. (2015) to be presented here for comparison.

An Investigation of the Acute Effects of Oligofructose-Enriched Inulin on Subjective Wellbeing, Mood and Cognitive Performance.

Inulin is a natural food component found in many plants that are part of the human diet (e.g., leeks, onions, wheat, garlic, chicory and artichokes). It is added to many foods and is used to increase dietary fibre, replace fats or carbohydrates, and as a prebiotic (a stimulant of beneficial bacteria in the colon). Oligofructose, which is also present in these foods, produces similar effects and most research has used a combination of these products. A previous study (Smith, 2005) investigated the effects of regular consumption of oligofructose-enriched inulin on wellbeing, mood, and cognitive performance in humans. The results showed that oligofructose-enriched inulin had no negative effects but that it did not improve wellbeing, mood, or performance. The aim of the present study was to examine the acute effects of oligofructose-enriched inulin (5 g) over a 4 h period during which the participants remained in the laboratory. A double blind placebo (maltodextrin) controlled study (N = 47) was carried out with the order of conditions being counterbalanced and the two sessions a week apart. On each test day mood and cognitive performance were assessed at baseline (at 8:00) and then following inulin or placebo (at 11:00). Prior to the second test session (at 10:30) participants completed a questionnaire assessing their physical symptoms and mental health during the test morning. The inulin and placebo were provided in powder form in 5 g sachets. Volunteers consumed one sachet in decaffeinated tea or decaffeinated coffee with breakfast (9:00). Questionnaire results showed that on the day that the inulin was consumed, participants felt happier, had less indigestion and were less hungry than when they consumed the placebo. As for performance and mood tasks, the most consistent effects were on the episodic memory tasks where consumption of inulin was associated with greater accuracy on a recognition memory task, and improved recall performance (immediate and delayed). Further research is required to identify the mechanisms that underlie this effect with glucose metabolism being one candidate.

Grazing, cognitive performance and mood.

Two experiments were carried out to examine how spreading food intake between either two or four occasions would affect mood and cognition. The first experiment used 96 participants in a between subject design where participants received either two milkshakes at 09:00 and 13:00 or four (half nutrient content but same volume) milkshakes at 09:00, 11:00, 13:00 and 15:00. The results showed that verbal reasoning accuracy improved in the four-milkshake condition. The second experiment used 24 participants in a cross-over design. The breakfast and lunch were halved in one condition and not in the other so participants either ate breakfast and lunch, or four meals at the same times as experiment 1. Verbal reasoning accuracy was improved by spreading the intake over four meals such that errors were reduced by between 30 and 40%. Speed was also increased in a five-item (but not one-item) search task. Further research is now necessary to uncover the mechanisms that underlie these effects.

Effects of repeated doses of caffeine on performance and alertness: new data and secondary analyses.

RATIONALE: The effects of caffeine on mood and performance are well established. Some authors suggest that caffeine merely reverses effects of caffeine withdrawal rather than having direct behavioural effects. It has also been suggested that withdrawal may be removed by a first dose of caffeine and further doses have little subsequent effect. These issues are examined here. OBJECTIVES: The present study aimed to determine whether caffeine withdrawal influenced mood and performance by comparing regular consumers who had been withdrawn from caffeine overnight with non-consumers. Following this repeated caffeine doses were administered to test the claim that repeated dosing has no extra effect on mood or performance. Secondary analyses of data collected after a day of normal caffeine consumption were also carried out to examine some alternative explanations of their results which showed effects of caffeine after a day of normal caffeine consumption. METHODS: One hundred and twenty volunteers participated in the study. Regular caffeine consumption was assessed by questionnaire and this showed that 36 of the volunteers did not regularly consume caffeinated beverages. Volunteers were instructed to abstain from caffeine overnight and then completed a baseline session measuring mood and a range of cognitive functions at 08.00 the next day. Following this volunteers were given 0, or 1 mg/kg caffeine in a milkshake, glucose solution or water (at 09:00), followed by a second 0 or 1 mg/kg caffeine dose (at 09:40) and the test battery repeated at 10:00. RESULTS: The baseline data showed no effect of overnight caffeine withdrawal on mood or performance. In contrast, caffeine challenge improved vigilance performance and prevented decreases in alertness induced by completion of the task battery. The magnitude of these effects increased as a function of the number of doses of caffeine given. Secondary analyses of data from Christopher et al. (2003) also confirmed that effects of caffeine did not depend on length of withdrawal. CONCLUSIONS: The present findings show no effect of overnight caffeine withdrawal on mood and performance. Caffeine challenge did have the predicted effect on alertness and vigilance, with the size of the effects increasing with caffeine dose. These findings suggest that the effects of caffeine are not due to reversal of effects of withdrawal, a view confirmed by secondary analyses of data collected after a day of normal caffeine consumption.

Acute effects of caffeine in volunteers with different patterns of regular consumption.

RATIONALE: The effects of caffeine on mood and performance are well established. One explanation of these effects is that caffeine removes negative effects induced by prior caffeine withdrawal. This was tested here by comparing effects of caffeine in withdrawn consumers and non-consumers (who by definition were not withdrawn). OBJECTIVES: The present study aimed to determine whether caffeine withdrawal influenced mood and performance by comparing regular consumers who had been withdrawn from caffeine overnight with non-consumers. Following this the effects of acute caffeine challenges were compared in withdrawn consumers and non-consumers. In addition, comparisons were made between those with higher and lower caffeine consumption. METHODS: One hundred seventy-six volunteers participated in the study. Regular caffeine consumption was assessed by questionnaire and this showed that 56 of the sample did not regularly consume caffeinated beverages. Volunteers were instructed to abstain from caffeine overnight and then completed a baseline session measuring mood and a range of cognitive functions at 08.00 the next day. Following this approximately half of the volunteers were given 1 mg/kg caffeine in a milkshake or water (in the 'no caffeine' condition they were given just the milkshake or water) and the test battery repeated one hour later. A second test battery was carried out at 12.00 and a second caffeine challenge at 13.00. A final test session was carried out at 15.00. RESULTS: The baseline data revealed little evidence of effects of caffeine withdrawal on performance and mood. In contrast to this, caffeine produced a number of significant improvements in performance. There were some differences in the effects of caffeine on regular and non-consumers, with caffeine tending to reduce reaction time in regular consumers while the opposite was true for non-consumers. CONCLUSIONS: The present results show little evidence of effects of caffeine withdrawal on performance. In contrast, caffeine challenge produced improvements in aspects of performance and these were often not modified by regular caffeine consumption patterns. The differences in effects of caffeine that were observed between non-consumers and regular consumers were in functions that were unaffected by caffeine withdrawal. These findings show that the observed beneficial effects of caffeine cannot be interpreted in terms of a reversal of caffeine withdrawal.

Correlates of daily caffeine consumption.

A study of 376 young British adults showed that estimated daily caffeine consumption increased with age, and was associated with smoking and greater alcohol consumption. Non-consumers of caffeine avoided tea and coffee (even the de-caffeinated form). Level of caffeine consumption was not associated with impulsivity, sociability, extraversion or trait anxiety.