Older Australian Twins Study

CHeBA Longitudinal Study: Older Australian Twins Study
Since 2007, the longitudinal Older Australian Twins Study has investigated the genetic and environmental contributions to healthy ageing, in particular ageing in the absence of brain dysfunction and disease, in twins aged 65 years and beyond.


The Older Australian Twins Study is a longitudinal study investigating healthy brain ageing in older twins (65+ years). Healthy ageing is characterised by low levels of disability, high cognitive and functional capacity, and an active engagement in life. The most important ingredient of healthy ageing is a healthy brain, bereft of age-related diseases and dysfunction. Brain ageing and brain diseases are determined by multiple genetic factors that interact with environmental influences. Since identical twins share 100% of their genes, whereas non-identical twins share half the genetic information, detailed comparisons of these two groups has the potential to discover new genes involved in cognitive decline or resilience.

OATS commenced in New South Wales in January 2007, in Queensland in December 2007, and in Victoria in February 2008. Since the OATS study started we have followed our twin volunteers up every two years to check on their psychological and physical health. Participants undergo rigorous medical and cognitive function tests, with many participants also providing bloods samples and having a magnetic resonance imaging (MRI) scan of their brain. OATS assessed 623 participants at baseline, 450 had a 2nd follow-up between 2009-2013, and 392 had a third follow-up between 2012 and 2016.

OATS Assesments

OATS Assesments

We are currently finishing an OATS imaging sub-study investigating the deposition of amyloid plaques in the brain using positron emission tomography (PET) scans. Amyloid plaques are thought to predict memory decline with age. Performing these scans in twins will help us to establish how these amyloid plaques relate to performance in memory and thinking ability. We also aim to determine if there is a genetic component, and if there are any potentially modifiable environmental factors that may be contributing to the development of the plaques. For this sub-study, 207 participants in New South Wales and Victoria were assessed and scanned.

The OATS Study has collected a unique data set from which we can examine genetic and environmental influences on a range of ageing-related issues. In particular we are investigating links between cognitive function and brain chemistry over time which has not been looked at previously. The diversity and depth of our work has also allowed us to form collaborative partnerships with other twin studies around the world. These collaborations are important as we have the opportunity to further enlarge our sample size and thereby better address genetic questions, which require large samples.

To request OATS data please contact the CHeBA Research Bank via email on CHeBAData@unsw.edu.au for a current application form.


The OATS aims to find out what influences memory and thinking as we age. It investigates environmental influences such as lifetime physical and mental activity, socioeconomic environment, and nutrition. It also investigates how biological factors such as hypertension and antioxidant levels interact with genes to influence brain ageing. Over time, the expression of genes varies depending on different influences in the environment, and by studying twins, OATS aims to determine which influences on the ageing process are genetic, which are environmental, and how the two interact.


Older Australian Twins Study Newsletter, December 2021

Older Australian Twins Study Newsletter, December 2020

Older Australian Twins Study Newsletter, December 2017


For all CHeBA publications, see Publications.

Methodology Papers

Authors Title Journal
Sachdev PS, Lammel A, Trollor JN, Lee T, Wright MJ, Ames D, et al. A comprehensive neuropsychiatric study of elderly twins: the Older Australian Twins Study. Twin Res Hum Genet., 2009;12(6):573-582. doi.org/10.1375/twin.12.6.573
Sachdev PS, Lee T, Wen W, Ames D, Batouli AH, Bowden J, et al. The contribution of twins to the study of cognitive ageing and dementia: the Older Australian Twins Study. Int Rev Psychiatry, 2013;25(6):738-747. doi.org/10.3109/09540261.2013.870137

Latest Papers

Authors Title Journal
Koncz R, Mohan A, Dawes L, Thalamuthu A, Wright M, Ames D, et al. Incidental findings on cerebral MRI in twins: the Older Australian Twins Study Brain Imaging and Behavior, 2018 June;12(3):860–869. doi.org/10.1007/s11682-017-9747-2
Lee T, Thalamuthu A, Henry JD, Trollor J, Ames D, Wright MJ, Sachdev PS, OATS Research Team Genetics and environmental influences on language ability in older adults: Findings from the Older Australian Twins Study. Behavior Genetics, 2018 May;48(3):187-197. doi.org/10.1007/s10519-018-9897-z


Current Students

Course type Student Supervisor(s) University
PhD Abdullah Alqarni Wei Wen UNSW
PhD Heidi Foo Perminder Sachdev, Wei Wen UNSW
PhD Rebecca Koncz Perminder Sachdev UNSW
PhD Andrea Lammel Perminder Sachdev Macquarie
PhD Annette Spooner Perminder Sachdev, Arcot Sowmya UNSW
PhD Abdusalam Toyin Ademola Perminder Sachdev, Anbu Thalamuthu, Karen Mather UNSW
Honours Andy Yu Wei Wen UNSW
PhD Chao Dong Wei Wen UNSW
PhD Yue Liu Wei Wen, Perminder Sachdev, Nady Braidy UNSW
ILP Christabella Surono Vibeke Catts, Teresa Lee, Perminder Sachdev UNSW
PhD Annabel Matison Karen Mather UNSW

Completed Students

Title Student Supervisor(s) University Year
Heritability of Excessive Daytime Sleepiness and Associated Inflammation in Older Australian Twins Tanya Duckworth Julian Troller, Greg Roach CQU CQU, Honours 2012
Genetic and Environmental Influences on Neuropsychological Functioning in Later Life: The Older Australian Twins Study Teresa Lee Perminder Sachdev UNSW, PhD 2013
Genetic and Environmental Influences on Brain Structure and Biochemistry in the Elderly: Data from the Older Australian Twins Study S.A.H.Batouli Perminder Sachdev, Julian Trollor and Wei Wen UNSW, PhD 2013
Examination of DNA Methylation in the APOA1 Gene Jessica Lazarus Karen Mather, John Kwok (NeuRA) UNSW, Honours 2013
Genetics of the White Matter Integrity in the Ageing Brain Sri Chandana Kanchibhotla Karen Mather UNSW, Masters 2015
The Relationships of Inflammation with Brain Structures in Older Individuals as Revealed by Multimodal Magnetic Resonance Imaging Techniques Jiyang Jiang Wei Wen, Julian Trollor, Perminder Sachdev UNSW, PhD 2016
Homocysteine Levels & May Be Depression, Dementia, Cognitive Performance, Neuroimaging Ng Wan Qi (Sandra) Karen Mather UNSW, ILP 2016
Brain Networks in Healthy Ageing and Psychiatric Conditions Alistair Perry Wei Wen, Perminder Sachdev, Michael Breakspear UNSW, PhD 2017
Glucose and Brain Health: Lessons from the Older Australian Twins Study Emily Hartman Katherine Samaras University of Notre Dame, Honours 2018
Investigating the Use of Genetic Risk Scores for Hippocampal Volumes in Older Adults Wey-Lynn Liew Karen Mather UNSW, ILP 2018
Nature and Nurture: Insights From Genetic, Environmental and Epigenomic Studies of Late-Life Depression Ruby Tsang Karen Mather UNSW, PhD 2018
Longitudinal Changes in Episodic Memory Performance and Brain Volumes, and their Association, in Older Australian Twins Dansen Ken-Gin Cho Vibeke Catts, Teresa Lee UNSW, ILP 2019
Investigating the Relationship Between Diet, Lipids and DNA Methylation in Older Adults Jun woo Park Karen Mather UNSW, ILP 2019
Investigating the Genetics of Olfaction in Older Adults Siddharth Raj Karen Mather UNSW, ILP 2019
Investigating the Transcriptome Signature of Depression: Employing Co-expression Network, Candidate Pathways and Machine Learning Approaches Liliana Ciobanu Berhard Baune, Catherine Toben Uni Adelaide, PhD 2019
The Role of Peripheral Blood MicroRNA as a Biomarker of Alzheimer’s Disease Helen Wu Karen Mather, Perminder Sachdev, Henry Brodaty   UNSW, PhD 2019
Comprehensive Identification of Natural Variation in the Human Plasma Lipidome Signature using Mass Spectrometry: Relevance to Promoting Healthy Ageing
Matthew Wong Anne Poljak UNSW, PhD 2019
The relationship between dietary patterns and neurocognitive health among older adults Yue Liu Wei Wen, Perminder Sachdev, Nady Braidy UNSW, PhD 2020


Study Coordinator

Dr Vibeke Catts

Research Assistant

Dr Amanda Selwood

OATS Investigators

Professor David Ames
Professor Bernhard Baune
Professor Henry Brodaty
Dr John Crawford
Dr Teresa Lee
Professor Nick Martin
Dr Karen Mather
Professor Christopher Rowe
Professor Perminder Sachdev
Professor Katherine Samaras
Professor Peter Schofield
Professor Julian Trollor
Associate Professor Wei Wen
Associate Professor Margie Wright

OATS Collaborators and Researchers

Professor Lesley Campbell
Dr Mari Kondo
Dr Michelle Lupton
Dr Julia Muenchhoff
Dr Anne Poljak
Dr Anbupalam Thalamuthu