Psychiatry - Research Publications

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    Higher coffee consumption is associated with slower cognitive decline and Aβ‐amyloid accumulation over 126 months: Data from the AIBL study
    Gardener, SL ; Rainey‐Smith, SR ; Villemagne, VLL ; Fripp, J ; Dore, V ; Bourgeat, P ; Taddei, K ; Masters, CL ; Maruff, PT ; Rowe, CC ; Ames, D ; Martins, RN (Wiley, 2021-12)
    Background Worldwide, coffee is one of the most popular beverages consumed. Several studies have suggested a protective role of coffee, including reduced risk of Alzheimer’s disease (AD). However, there is limited longitudinal data available in cohorts of older adults reporting associations of coffee intake with cognitive decline, in distinct domains, and investigating the neuropathological mechanisms underpinning these associations. Method The aim of the current study was to investigate the relationship between self‐reported baseline coffee intake (mean = 280 ± 323 g/day) and cognitive decline assessed using a comprehensive neuropsychological battery, over 126 months, in 227 cognitively normal individuals from the Australian Imaging, Biomarkers, and Lifestyle (AIBL) study. We also sought to investigate the relationship between coffee intake and cerebral Aβ‐amyloid accumulation and brain volumes in a subset of individuals (n=60; and n=51, respectively) over 126 months. Result Higher baseline coffee consumption was associated with slower cognitive decline in executive function, attention, and the AIBL Preclinical AD Cognitive Composite (PACC; shown to reliably measure the first signs of cognitive decline in at‐risk cognitively normal populations) over 126 months. Higher baseline coffee consumption was also associated with slower Aβ‐amyloid accumulation over 126 months, and lower risk of transitioning from ‘negative’ Aβ‐amyloid status to ‘moderate’, and ‘very high’ Aβ‐amyloid burden over the same time period. There were no associations between coffee intake and atrophy in total grey matter, white matter, or hippocampal volume. Conclusion Our results further support the hypothesis that coffee intake may be a protective factor against AD, with increased coffee consumption reducing cognitive decline potentially by slowing cerebral Aβ‐amyloid accumulation, and thus attenuating the associated neurotoxicity from Aβ‐amyloid‐mediated oxidative stress and inflammatory processes. Further investigation is required to evaluate how coffee intake could be incorporated as one modifiable lifestyle factor aimed at delaying AD onset.
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    How lifestyle shapes the brain: Associations between physical activity, sleep, beta‐amyloid and cognitive function in older adults
    Sewell, KR ; Rainey‐Smith, SR ; Villemagne, VLL ; Peiffer, JJ ; Sohrabi, HR ; Taddei, K ; Ames, D ; Maruff, PT ; Laws, SM ; Masters, CL ; Rowe, CC ; Martins, RN ; Erickson, KI ; Brown, BM (Wiley, 2021-12)
    Abstract Background Lifestyle factors such as sleep and physical activity influence risk of cognitive decline and dementia. Higher habitual physical activity and optimal sleep are associated with better cognitive function and lower levels of Alzheimer’s disease biomarkers, including beta‐amyloid (Aß). There is currently a poor understanding of how physical activity may influence the relationship between sleep and cognition, and whether exercise and sleep interact to influence cognition and Aß. Developing this understanding is crucial for creating effective lifestyle interventions for dementia prevention. Method Data from the Australian Imaging, Biomarkers and Lifestyle (AIBL) study were utilised to determine whether self‐reported physical activity moderates the cross‐sectional relationship between self‐reported sleep parameters (duration, efficiency, latency, disturbance, quality), cognitive function (episodic memory, attention and processing speed, executive function), and brain Aß (quantified by amyloid positron emission tomography, using the Centiloid scale). Analyses were adjusted for age, sex, APOE ε4 carriage, mood, premorbid intelligence, and collection point. Participants were 404 community‐dwelling cognitively normal older adults aged 60 and above (75.3 5.7 years). Data from a subset of participants (n = 220, aged 75.2 5.6 years) were used for analyses with AB as the outcome. Result Physical activity moderated the relationship between sleep duration and episodic memory (ß = ‐.09, SE = .03, p = .005), and sleep efficiency and episodic memory (ß = ‐.08, SE = .03, p = .016). Physical activity moderated the relationship between sleep duration and A® (ß = ‐.12, SE = .06, p = .036), and sleep quality and Aß (ß = .12, SE = .06, p = .029). Conclusion Physical activity may play an important role in the relationship between sleep and cognitive function, and sleep and brain Aß. Future longitudinal and intervention studies in this area are crucial for informing interventions for dementia prevention.
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    Investigating Olfactory Gene Variation and Odour Identification in Older Adults
    Raj, S ; Thalamuthu, A ; Armstrong, NJ ; Wright, MJ ; Kwok, JB ; Trollor, JN ; Ames, D ; Schofield, PR ; Brodaty, H ; Sachdev, PS ; Mather, KA (MDPI, 2021-05)
    Ageing is associated with a decrease in odour identification. Additionally, deficits in olfaction have been linked to age-related disease and mortality. Heritability studies suggest genetic variation contributes to olfactory identification. The olfactory receptor (OR) gene family is the largest in the human genome and responsible for overall odour identification. In this study, we sought to find olfactory gene family variants associated with individual and overall odour identification and to examine the relationships between polygenic risk scores (PRS) for olfactory-related phenotypes and olfaction. Participants were Caucasian older adults from the Sydney Memory and Ageing Study and the Older Australian Twins Study with genome-wide genotyping data (n = 1395, mean age = 75.52 ± 6.45). The Brief-Smell Identification Test (BSIT) was administered in both cohorts. PRS were calculated from independent GWAS summary statistics for Alzheimer's disease (AD), white matter hyperintensities (WMH), Parkinson's disease (PD), hippocampal volume and smoking. Associations with olfactory receptor genes (n = 967), previously identified candidate olfaction-related SNPs (n = 36) and different PRS with BSIT scores (total and individual smells) were examined. All of the relationships were analysed using generalised linear mixed models (GLMM), adjusted for age and sex. Genes with suggestive evidence for odour identification were found for 8 of the 12 BSIT items. Thirteen out of 36 candidate SNPs previously identified from the literature were suggestively associated with several individual BSIT items but not total score. PRS for smoking, WMH and PD were negatively associated with chocolate identification. This is the first study to conduct genetic analyses with individual odorant identification, which found suggestive olfactory-related genes and genetic variants for multiple individual BSIT odours. Replication in independent and larger cohorts is needed.
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    A Randomized Controlled Trial on the Effects of a 6-Month Home-Based Physical Activity Program with Individual Goal-Setting and Volunteer Mentors on Physical Activity, Adherence, and Physical Fitness in Inactive Older Adults at Risk of Cognitive Decline: The INDIGO Study
    Cox, KL ; Clare, L ; Cyarto, E ; Ellis, KA ; Etherton-Beer, C ; Southam, J ; Ames, D ; Flicker, L ; Almeida, OP ; LoGiudice, D ; Liew, D ; Vlaskovsky, P ; Lautenschlager, NT ; Hauer, K (IOS PRESS, 2021)
    BACKGROUND: Increasing physical activity (PA) in those who have memory concerns requires innovative approaches. OBJECTIVE: To compare in this randomized controlled trial (RCT) the effects on PA, adherence, and fitness of two approaches to deliver a 6-month home-based PA program in older, inactive individuals at risk of cognitive decline. METHODS: Individuals (n = 52) aged 60-85 years, inactive with mild cognitive impairment or subjective cognitive decline were recruited from the community and memory clinics. Randomization was to 6 months of 150 min/week moderate intensity PA with either: goal-setting with mentor support; or education and peer contact. A subset of participants (n = 36) continued for a further 6 months. PA, moderate and vigorous PA, and secondary outcomes, fitness, goal performance/satisfaction and self-efficacy were assessed at baseline, 6 and 12 months. Modelling of primary and secondary outcomes was conducted with linear mixed models. RESULTS: Participants were mean age (±sd) 70.1 (6.4) years. Six-month retention was 88.5%(n = 46). No significant between-group differences were observed for PA or fitness. Post-hoc combined group data showed a significant, moderate-large effect size increase in PA with time. PA increased by a mean 1,662 (943, 2383) steps/day (95%CI) and 1,320 (603, 2037) steps/day at 6 and 12 months (p < 0.001). Median (quartiles Q1-Q3) 6 and 6-12 month combined group adherence was 88.9 (74.4-95.7)%and 84.6 (73.9-95.4)%respectively. CONCLUSION: In this target group, no differences were detected between groups both intervention strategies were highly effective in increasing PA and fitness.
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    Non-negative matrix factorisation improves Centiloid robustness in longitudinal studies
    Bourgeat, P ; Dore, V ; Doecke, J ; Ames, D ; Masters, CL ; Rowe, CC ; Fripp, J ; Villemagne, VL (ACADEMIC PRESS INC ELSEVIER SCIENCE, 2021-02-01)
    BACKGROUND: Centiloid was introduced to harmonise β-Amyloid (Aβ) PET quantification across different tracers, scanners and analysis techniques. Unfortunately, Centiloid still suffers from some quantification disparities in longitudinal analysis when normalising data from different tracers or scanners. In this work, we aim to reduce this variability using a different analysis technique applied to the existing calibration data. METHOD: All PET images from the Centiloid calibration dataset, along with 3762 PET images from the AIBL study were analysed using the recommended SPM pipeline. The PET images were SUVR normalised using the whole cerebellum. All SUVR normalised PiB images from the calibration dataset were decomposed using non-negative matrix factorisation (NMF). The NMF coefficients related to the first component were strongly correlated with global SUVR and were subsequently used as a surrogate for Aβ retention. For each tracer of the calibration dataset, the components of the NMF were computed in a way such that the coefficients of the first component would match those of the corresponding PiB. Given the strong correlations between the SUVR and the NMF coefficients on the calibration dataset, all PET images from AIBL were subsequently decomposed using the computed NMF, and their coefficients transformed into Centiloids. RESULTS: Using the AIBL data, the correlation between the standard Centiloid and the novel NMF-based Centiloid was high in each tracer. The NMF-based Centiloids showed a reduction of outliers, and improved longitudinal consistency. Furthermore, it removed the effects of switching tracers from the longitudinal variance of the Centiloid measure, when assessed using a linear mixed effects model. CONCLUSION: We here propose a novel image driven method to perform the Centiloid quantification. The methods is highly correlated with standard Centiloids while improving the longitudinal reliability when switching tracers. Implementation of this method across multiple studies may lend to more robust and comparable data for future research.
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    Assessment of the DTI-ALPS Parameter Along the Perivascular Space in Older Adults at Risk of Dementia
    Steward, CE ; Venkatraman, VK ; Lui, E ; Malpas, CB ; Ellis, KA ; Cyarto, EV ; Vivash, L ; O'Brien, TJ ; Velakoulis, D ; Ames, D ; Masters, CL ; Lautenschlager, NT ; Bammer, R ; Desmond, PM (WILEY, 2021-05)
    BACKGROUND AND PURPOSE: Recently, there has been growing interest in the glymphatic system (the functional waste clearance pathway for the central nervous system and its role in flushing solutes (such as amyloid ß and tau), metabolic, and other cellular waste products in the brain. Herein, we investigate a recent potential biomarker for glymphatic activity (the diffusion tensor imaging along the perivascular space [DTI-ALPS] parameter) using diffusion MRI imaging in an elderly cohort comprising 10 cognitively normal, 10 mild cognitive impairment (MCI), and 16 Alzheimer's disease (AD). METHODS: All 36 participants imaged on a Siemens 3.0T Tim Trio. Single-SE diffusion weighted Echo-planar imaging scans were acquired as well as T1 magnetization prepared rapid gradient echo, T2 axial, and susceptibility weighted imaging. Three millimeter regions of interest were drawn in the projection and association fibers adjacent to the medullary veins at the level of the lateral ventricle. The DTI-ALPS parameter was calculated in these regions and correlated with cognitive status, Mini-Mental State Examination (MMSE), and ADASCog11 measures. RESULTS: Significant correlations were found between DTI-ALPS and MMSE and ADASCog11 in the right hemisphere adjusting for age, sex, and APoE ε4 status. Significant differences were also found in the right DTI-ALPS indices between cognitively normal and AD groups (P < .026) and MCI groups (P < .025) in a univariate general linear model corrected for age, sex, and APoE ε4. Significant differences in apparent diffusion coefficient between cognitively normal and AD groups were found in the right projection fibers (P = .028). CONCLUSION: Further work is needed to determine the utility of DTI-ALPS index in larger elderly cohorts and whether it measures glymphatic activity.
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    Epigenome-wide meta-analysis of blood DNA methylation and its association with subcortical volumes: findings from the ENIGMA Epigenetics Working Group
    Jia, T ; Chu, C ; Liu, Y ; van Dongen, J ; Papastergios, E ; Armstrong, NJ ; Bastin, ME ; Carrillo-Roa, T ; den Braber, A ; Harris, M ; Jansen, R ; Liu, J ; Luciano, M ; Ori, APS ; Santianez, RR ; Ruggeri, B ; Sarkisyan, D ; Shin, J ; Sungeun, K ; Gutierrez, DT ; van't Ent, D ; Ames, D ; Artiges, E ; Bakalkin, G ; Banaschewski, T ; Bokde, ALW ; Brodaty, H ; Bromberg, U ; Brouwer, R ; Buchel, C ; Quinlan, EB ; Cahn, W ; de Zubicaray, G ; Ehrlich, S ; Ekstrom, TJ ; Flor, H ; Frohner, JH ; Frouin, V ; Garavan, H ; Gowland, P ; Heinz, A ; Hoare, J ; Ittermann, B ; Jahanshad, N ; Jiang, J ; Kwok, JB ; Martin, NG ; Martinot, J-L ; Mather, KA ; McMahon, KL ; McRae, AF ; Nees, F ; Orfanos, DP ; Paus, T ; Poustka, L ; Samann, PG ; Schofield, PR ; Smolka, MN ; Stein, DJ ; Strike, LT ; Teeuw, J ; Thalamuthu, A ; Trollor, J ; Walter, H ; Wardlaw, JM ; Wen, W ; Whelan, R ; Apostolova, LG ; Binder, EB ; Boomsma, D ; Calhoun, V ; Crespo-Facorro, B ; Deary, IJ ; Pol, HH ; Ophoff, RA ; Pausova, Z ; Sachdev, PS ; Saykin, A ; Wright, MJ ; Thompson, PM ; Schumann, G ; Desrivieres, S (SPRINGERNATURE, 2021-08)
    DNA methylation, which is modulated by both genetic factors and environmental exposures, may offer a unique opportunity to discover novel biomarkers of disease-related brain phenotypes, even when measured in other tissues than brain, such as blood. A few studies of small sample sizes have revealed associations between blood DNA methylation and neuropsychopathology, however, large-scale epigenome-wide association studies (EWAS) are needed to investigate the utility of DNA methylation profiling as a peripheral marker for the brain. Here, in an analysis of eleven international cohorts, totalling 3337 individuals, we report epigenome-wide meta-analyses of blood DNA methylation with volumes of the hippocampus, thalamus and nucleus accumbens (NAcc)-three subcortical regions selected for their associations with disease and heritability and volumetric variability. Analyses of individual CpGs revealed genome-wide significant associations with hippocampal volume at two loci. No significant associations were found for analyses of thalamus and nucleus accumbens volumes. Cluster-based analyses revealed additional differentially methylated regions (DMRs) associated with hippocampal volume. DNA methylation at these loci affected expression of proximal genes involved in learning and memory, stem cell maintenance and differentiation, fatty acid metabolism and type-2 diabetes. These DNA methylation marks, their interaction with genetic variants and their impact on gene expression offer new insights into the relationship between epigenetic variation and brain structure and may provide the basis for biomarker discovery in neurodegeneration and neuropsychiatric conditions.
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    The Support Person's Preferences and Perspectives of Physical Activity Programs for Older Adults With Cognitive Impairment
    Chong, TWH ; You, E ; Ellis, KA ; Cox, KL ; Harrington, KD ; Rainey-Smith, SR ; Ames, D ; Lautenschlager, NT (FRONTIERS MEDIA SA, 2021-09-23)
    Objectives: Physical activity (PA) is beneficial for older adults' cognition. There is limited research investigating perspectives of support persons (SPs) of next-of-kins (NOKs) with cognitive impairment. This exploratory study aimed to investigate perspectives of SPs of older adults with Alzheimer's Dementia (AD) or Mild Cognitive Impairment (MCI). Methods: A telephone survey of 213 SPs of NOKs from the Australian Imaging, Biomarkers and Lifestyle Flagship Study of Ageing (AIBL) was undertaken to quantitatively assess SPs' beliefs and knowledge about PA benefits, current PA level of their NOK, and PA program preferences. The contribution of age, gender, diagnosis and mental health symptoms was assessed using multiple logistic regression analyses. Results: Many SPs were aware of PA benefits for memory (64%) and believed it would help their NOK (72%). Older SP age was associated with less awareness of benefits (p = 0.016). SPs caring for male NOKs were more likely to believe that PA would be helpful than those caring for female NOKs (p = 0.049). NOK AD diagnosis (rather than MCI) (p = 0.014), older age (p = 0.005) and female gender (p = 0.043) were associated with lower PA levels. SPs were mixed regarding preference for their NOKs to participate in individual (45%) or group (54%) PA. Many SPs wanted to participate in PA with their NOK (63%). Conclusions: The results highlight that SPs have high levels of awareness of the cognitive benefits of PA, and describe their preferences regarding PA programs. The findings provide new information to inform targeted public health messaging, PA prescribers and providers, and future research directions.
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    Promoting Independence Through quality dementia Care at Home (PITCH): a research protocol for a stepped-wedge cluster-randomised controlled trial
    Savvas, S ; Goh, AMY ; Batchelor, F ; Doyle, C ; Wise, E ; Tan, E ; Panayiotou, A ; Malta, S ; Winbolt, M ; Clarke, P ; Burton, J ; Low, L-F ; Loi, SM ; Fairhall, A ; Polacsek, M ; Stiles, J ; Muliadi, F ; Chau, N ; Scherer, S ; Ames, D ; Sousa, TV ; Dow, B (BMC, 2021-12-20)
    BACKGROUND: Home care service providers are increasingly supporting clients living with dementia. Targeted and comprehensive dementia-specific training for home care staff is necessary to meet this need. This study evaluates a training programme delivered to care staff (paid personal carers) of clients living with dementia at home. METHODS: This study is a pragmatic stepped-wedge cluster-randomised controlled trial (SW-CRT). Home care workers (HCWs) from seven home care service providers are grouped into 18 geographical clusters. Clusters are randomly assigned to intervention or control groups. The intervention group receives 7 h of a dementia education and upskilling programme (Promoting Independence Through quality dementia Care at Home [PITCH]) after baseline measures. The control group receives PITCH training 6 months after baseline measures. This approach will ensure that all participants are offered the program. Home care clients living with dementia are also invited to participate, as well as their family carers. The primary outcome measure is HCWs' sense of competence in dementia care provision. DISCUSSION: Upskilling home care staff is needed to support the increasing numbers of people living with dementia who choose to remain at home. This study uses a stepped-wedge cluster-randomised trial to evaluate a training programme (PITCH) for dementia care that is delivered to front-line HCWs. TRIAL REGISTRATION: anzctr.org.au ; ACTRN12619000251123. Registered on 20 February 2019.
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    Dementia and caregiver burden: A three-year longitudinal study
    Connors, MH ; Seeher, K ; Teixeira-Pinto, A ; Woodward, M ; Ames, D ; Brodaty, H (WILEY, 2020-02)
    OBJECTIVES: Dementia, with its progressive cognitive and functional decline and associated neuropsychiatric symptoms, places a large burden on caregivers. While frequently studied, longitudinal findings about the overall trajectory of burden are mixed. The study sought to characterize caregiver burden over a 3-year period and identify predictors of this burden. METHODS: Seven-hundred-and-eighty-one patients with dementia were recruited from nine memory clinics around Australia. Measures of caregiver burden, cognition, function, and neuropsychiatric symptoms were completed with patients and their caregivers at regular intervals over a 3-year period. Patients' level of services and medication use were also recorded. RESULTS: Of the 720 patients with measures of caregiver burden at baseline, 47.4% of caregivers had clinically significant levels of burden. This proportion increased over time, with 56.8% affected at 3 years. Overall levels of burden increased for caregivers of patients without services, though did not change for caregivers of patients receiving services or residential care after controlling for other variables. Patient characteristics-including greater neuropsychiatric symptoms, lower functional ability, fewer medications, lack of driving ability-and female sex of caregivers were associated with greater burden. CONCLUSIONS: High levels of caregiver burden are present in a large proportion of caregivers of people with dementia and this increases over time for those without services. Clinical characteristics of patients (including neuropsychiatric symptoms, function, overall health, driving status), level of services, and caregiver sex appear to be the best predictors of this burden. These characteristics may help identify caregivers at greater risk of burden to target for intervention.