Older Australian Twins Study

image - OATAS3
Project Main Description: 

The Older Australian Twins Study is a longitudinal, multi-centre study that investigates 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. In 2015 we finished our 4-year follow ups.  OATS assessed 623 participants at baseline, 450 at the 2-year follow up, and 389 completed their 4-year follow-up.

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 yet 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.


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. Since, over time, the expression of genes varies depending on different influences in the environment, by studying twins, OATS aims to determine which influences on the ageing process are genetic, which are environmental, and how the two interact.

New Study

In 2015 we started a new OATS 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. Please contact us for more information if you are interested in participating in this study.


Participate in Our Research

Identical and non-identical twin pairs, aged 65 and older, living in New South Wales, Queensland and Victoria are eligible to participate in this research. With few exceptions, twin pairs can participate regardless of whether or not they are experiencing any memory or health problems. Over a period of four years, participants are asked to undergo three medical and neuropsychological assessments (the core aspect), and answer questions about their health, lifestyle, memory and thinking. Some participants are also invited to provide blood samples, and have MRI brain scans. Participants may, however, choose to complete only the core aspect of the study.

In New South Wales, the medical and neuropsychological assessment can be done at the Prince of Wales Hospital, Sydney; in Victoria at the National Ageing Research Institute, Melbourne; and in Queensland at the Queensland Medical Research Institute, Brisbane.

For further information contact OATS on freecall 1800 81 TWIN or on email: twins@unsw.edu.au.


PhD Theses:

  • Lee T- Genetic and Environmental Influences on Neuropsychological Functioning in Later Life: The Older Australian Twins Study. UNSW, 2013. Supervisor: Perminder Sachdev, UNSW
  • Batouli SAH – Genetic and Environmental Influences on Brain Structure and Biochemistry in the Elderly: Data from the Older Australian Twins Study. UNSW, 2013. Supervisors: Perminder Sachdev, Julian Trollor and Wei Wen, UNSW

Honours Theses:

  • Duckworth T – Heritability of Excessive Daytime Sleepiness and Associated Inflammation in Older Australian Twins.Central Queensland University, 2012. Supervisors: Julian Trollor, UNSW and Greg Roach, CQU.


Journal publications:

Sachdev PS, Lammel A, Trollor JN, et al. A comprehensive neuropsychiatric study of elderly twins: the Older Australian Twins Study. Twin research and human genetics, 2009;12(6):573-82.

Lee T, Henry JD, Trollor JN, et al. Genetic influences on cognitive functions in the elderly: a selective review of twin studies. Brain research reviews, 2010;64(1):1-13.

Sachdev PS, Lee T, Lammel A, et al. Cognitive functioning in older twins: the Older Australian Twins Study. Australasian Journal on Ageing, 2011;30 Suppl 2:17-23.

Batouli SA, Sachdev PS, Wen W, et al. The heritability of brain metabolites on proton magnetic resonance spectroscopy in older individuals. NeuroImage, 2012;62(1):281-9.

Lee T, Crawford JD, Henry JD, et al. Mediating effects of processing speed and executive functions in age-related differences in episodic memory performance: a cross-validation study. Neuropsychology, 2012;26(6):776-84.

Lee T, Mosing MA, Henry JD, et al. Genetic influences on four measures of executive functions and their covariation with general cognitive ability: the Older Australian Twins Study. Behavior Genetics, 2012;42(4):528-38.

Lee T, Mosing MA, Henry JD, et al. Genetic influences on five measures of processing speed and their covariation with general cognitive ability in the elderly: the older Australian twins study. Behavior Genetics, 2012;42(1):96-106.

Sachdev P, Trollor J, Lammel A, et al. Recent findings from the Older Australian Twins Study (OATS). Alzheimer's & Dementia, 2012;8(4):P675.

Sachdev PS, Lee T, Wen W, et al. The contribution of twins to the study of cognitive ageing and dementia: the Older Australian Twins Study. International Review of Psychiatry, 2013;25(6):738-47.

Batouli SA, Sachdev PS, Wen W, et al. Heritability of brain volumes in older adults: the Older Australian Twins Study. Neurobiology of Aging, 2014;35(4):937 e5-18.

Batouli SA, Trollor JN, Wen W, et al. The heritability of volumes of brain structures and its relationship to age: a review of twin and family studies. Ageing Research Reviews, 2014;13:1-9.

Kanchibhotla SC, Mather KA, Thalamuthu A, et al. Genetics of microstructure of the corpus callosum in older adults. PloS One, 2014;9(12):e113181.

Lee T, Lipnicki DM, Crawford JD, et al. Leisure activity, health, and medical correlates of neurocognitive performance among monozygotic twins: the Older Australian Twins Study. Journals of Gerontology Series B, 2014;69(4):514-22.

Lee T, Sachdev P. The contributions of twin studies to the understanding of brain ageing and neurocognitive disorders. Current Opinion in Psychiatry, 2014;27(2):122-7.

Boraxbekk CJ, Ames D, Kochan NA, et al. Investigating the influence of KIBRA and CLSTN2 genetic polymorphisms on cross-sectional and longitudinal measures of memory performance and hippocampal volume in older individuals. Neuropsychologia, 2015;78:10-7.

Davies G, Armstrong N, Bis JC, et al. Genetic contributions to variation in general cognitive function: a meta-analysis of genome-wide association studies in the CHARGE consortium (N=53949). Molecular Psychiatry, 2015;20(2):183-92.

Hibar DP, Stein JL, Renteria ME, et al. Common genetic variants influence human subcortical brain structures. Nature, 2015;520(7546):224-9.

Lazarus J, Mather KA, Armstrong NJ, et al. DNA methylation in the apolipoprotein-A1 gene is associated with episodic memory performance in healthy older individuals. Journal of Alzheimer's Disease, 2015;44(1):175-82.

Mather KA, Armstrong NJ, Wen W, et al. Investigating the genetics of hippocampal volume in older adults without dementia. PloS One 2015;10(1):e0116920.

Willemsen G, Ward KJ, Bell CG, et al. The Concordance and Heritability of Type 2 Diabetes in 34,166 Twin Pairs From International Twin Registers: The Discordant Twin (DISCOTWIN) Consortium. Twin Research and Human Genetics, 2015;18(6):762-71.

Lupton MK, Strike L, Hansell NK, et al. The effect of increased genetic risk for Alzheimer's disease on hippocampal and amygdala volume. Neurobiology of Aging, 2016;40:68-77.



Older Australian Twins Study NSW

Study Coordinator

Dr Vibeke Catts

Research Assistant

Tanya Duckworth

Administrative Assistant

Suzy Forrester


Older Australian Twins Study QLD

Research Assistant

Natalie Garden


Older Australian Twins Study VIC

Research Assistant

Christel Lemmon


OATS Investigators

David Ames
Bernhard Baune
Henry Brodaty
John Crawford
Teresa Lee
Nick Martin
Karen Mather
Christopher Rowe
Perminder Sachdev

Katherine Samaras
Peter Schofield
Julian Trollor
Wei Wen
Margie Wright

OATS Collaborators and Researchers

Lesley Campbell
Michelle Lupton
Julia Muenchhoff
Anne Poljak
Anbupalam Thalamuthu

Project Status: 
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