Estimation of dietary flavonoid intake and cognitive performance in older adults with Alzheimer\u27s type dementia

Abstract presented at The Nutrition Society of Australia and Nutrition Society of New Zealand 2013 Joint Annual Scientific Meeting, 4-6 December 2013, Brisbane, Australi

Medication adherence in randomized controlled trials evaluating cardiovascular or mortality outcomes in dialysis patients: A systematic review

Background: Medication non-adherence is common among renal dialysis patients. High degrees of non-adherence in randomized controlled trials (RCTs) can lead to failure to detect a true treatment effect. Cardio-protective pharmacological interventions have shown no consistent benefit in RCTs involving dialysis patients. Whether non-adherence contributes to this lack of efficacy is unknown. We aimed to investigate how medication adherence and drug discontinuation were assessed, reported and addressed in RCTs, evaluating cardiovascular or mortality outcomes in dialysis patients. Methods: Electronic database searches were performed in MEDLINE, EMBASE & Cochrane CENTRAL for RCTs published between 2005-2015, evaluating self-administered medications, in adult dialysis patients, which reported clinical cardiovascular or mortality endpoints, as primary or secondary outcomes. Study characteristics, outcomes, methods of measuring and reporting adherence, and data on study drug discontinuation were analyzed. Results: Of the 642 RCTs in dialysis patients, 22 trials (12 placebo controlled), which included 19,322 patients, were eligible. The trialed pharmacological interventions included anti-hypertensives, phosphate binders, lipid-lowering therapy, cardio-vascular medications, homocysteine lowering therapy, fish oil and calcimimetics. Medication adherence was reported in five trials with a mean of 81% (range: 65-92%) in the intervention arm and 84.5% (range: 82-87%) in the control arm. All the trials that reported adherence yielded negative study outcomes for the intervention. Study-drug discontinuation was reported in 21 trials (mean 33.2%; 95% CI, 22.0 to 44.5, in intervention and 28.8%; 95% CI, 16.8 to 40.8, in control). Trials with more than 20% study drug discontinuation, more often yielded negative study outcomes (p = 0.018). Non-adherence was included as a contributor to drug discontinuation in some studies, but the causes of discontinuation were not reported consistently between studies, and non-adherence was listed under different categories, thereby potentiating the misclassification of adherence. Conclusions: Reporting of medication adherence and study-drug discontinuation in RCTs investigating cardiovascular or mortality endpoints in dialysis patients are inconsistent, making it difficult to compare studies and evaluate their impact on outcomes. Recommendations for consistent reporting of non-adherence and causes of drug discontinuation in RCTs will therefore help to assess their impact on clinical outcomes

Role for positive schizotypy and hallucination proneness in semantic processing

Semantic processing underpins the organization of verbal information for both storage and retrieval. Deficits in semantic processing are associated with both the risk for and symptoms presented in schizophrenia. However, studies are mixed and could reflect the confounding effects of medication and symptom heterogeneity. Therefore, we considered whether two risk phenotypes, positive schizotypy and hallucinatory predisposition, present in the general population were associated with differential responding profiles for a semantic processing task. One hundred and eighty-three participants completed the Schizotypal Personality Questionnaire, Launay-Slade Hallucination Scale, National Adult Reading Test, a handedness measure, and a computerized semantic relatedness judgment task. Pairs of words were related through their dominant or subordinate meanings, or unrelated. Participants were divided into four groups using a mean split on cognitive-perceptual (positive) schizotypy and hallucination proneness. Significant differences between groups were found for reaction time on the semantic relatedness task, with the high cognitive-perceptual schizotypy groups responding significantly slower to all word pairs compared to their low scoring counterparts. There was some evidence that high hallucination proneness was associated with significantly faster reaction times which may reflect disinhibitive processes, however additional support is required. The results suggest that these two components of psychosis risk are associated with different patterns of responding to semantic processing. More diffuse activation of semantic information appeared to be associated with positive schizotypy, while those predisposed to hallucinations appeared to respond quicker. These results have significant implications in the re-conceptualization of hallucination proneness as distinct from positive schizotypy. Additional research is required to investigate the association between psychotic-like experiences separate from personality variables such as positive schizotypy and semantic processing

Complex Scenes From the International Affective Picture System (IAPS)

Complex scenes from standardized stimuli databases such as the International Affective Picture System (IAPS) are organized dimensionally rather than discretely. Further, the potentially unique function of socially relevant scenes is often overlooked. This study sought to identify discrete categories of complex scenes from the IAPS and to explore if there were qualitative features that make the emotional content of some social scenes identifiable with higher levels of agreement. One hundred and three participants (53.4% female, mean age 24.4) judged 118 IAPS scenes as reflecting fear, happy, sad, or neutral. A second judgment study was conducted with a separate group of participants (N = 117; 79.2% female; mean age 30.41) to further characterize valid affective scenes across the full range of basic emotions. Sixty images received agreement on their emotional category from > 70% of judges and were considered valid. IAPS identifier codes for these images are available for reference (along with the supplementary material from the second judgment study), organized by emotional and social content. An incidental observation was such that compared to nonsocial scenes, lower agreement rates were observed for social scenes across the board. Qualitative features of social scenes that were classified into emotional categories based on higher levels of agreement are discussed

Dietary flavonoid intake and cognitive performance in older adults with Alzheimer\u27s type dementia

Background: Dietary flavonoid intake and intake of flavonoid subclasses has been associated with improved cognitive performance. However, the association between flavonoid intake and cognitive performance in older adults with Alzheimer\u27s type dementia has not been investigated. Objectives: To estimate dietary total flavonoid intake and intake of flavonoid subclasses in older adults with Alzheimer\u27s type dementia and assess the relationship of flavonoid intake with measures of cognition. Design: Cross sectional analysis. Setting: Community dwelling older adults in NSW, Australia. Participants: Older adults (+65y) with mild to moderate dementia (n=49). Measurements: A 24h diet recall was collected with help from a carer and used to estimate flavonoid intake. A battery of cognitive tasks assessed cognitive performance of several cognitive domains. Results: Pearson and spearman correlation coefficients identified an association between flavonoid intake and executive function (r=0.319, p=0.025). After controlling for depression, the relationship was reduced. Conclusion: The identified association between cognitive functioning, depression and flavonoid intake in older adults with Alzheimer\u27s type dementia warrants further research in a larger sample

The orthographic/phonological neighbourhood size effect and set size

A growing number of studies have shown that on serial recall tests, words with more orthographic/phonological neighbours are better recalled than otherwise comparable words with fewer neighbours, the so-called neighbourhood size effect. Greeno et al. replicated this result when using a large stimulus pool but found a reverse neighbourhood size effect—better recall of words with fewer rather than more neighbours—when using a small stimulus pool. We report three registered experiments that further examine the role of set size in the neighbourhood size effect. Experiment 1 used the large pool from Greeno et al. and replicated their finding of a large-neighbourhood advantage. Experiment 2 used the small pool from Greeno et al. but found no difference in recall between the large and small neighbourhood conditions. Experiment 3 also used a small pool but the small pool was randomly generated for each subject from the large pool used in Experiment 1. This resulted in a typical large neighbourhood advantage. We suggest that set size is not critical to the direction of the neighbourhood size effect, with a large neighbourhood advantage appearing with both small and large pools

Combined cognitive and state-control training for children with and without AD/HD: Effects on behaviour, working memory and resting EEG

Abstract presented at the 23rd Australasian Society for Psychophysiology Conference, 20-22 Nov 2013, Wollongong, Australi

Atypical interference control in children with AD/HD with elevated theta/beta ratio

The theta/beta ratio (TBR) is a major area of interest within electroencephalogram (EEG) research in AD/HD. While researchers suggest a prognostic role for TBR in AD/HD, its relationship to behavior remains uncertain. Recent evidence suggests that elevated TBR in AD/HD may be related to atypical inhibition, particularly at an attentional level. This study aimed to examine the performance on three inhibitory tasks of children with AD/HD. Fifty-eight children with AD/HD participated, divided into an elevated TBR (ET) group and a control group (CT). A behavioral disassociation was found − compared to CT, ET showed more difficulty in inhibiting surrounding stimuli but had less day-to-day inhibitory issues measured by BRIEF. There was no significant group difference on response inhibition. The results support the prognostic value of TBR in AD/HD. Elevated TBR may be an inhibitory biomarker; further studies are needed to explore the behavioral implications in patients without elevated TBR