Sax Institute Launches 18 and Up Cohort Study to Track Young Adult Health
Australia is launching a 100,000-person intergenerational study to track the health and ageing of younger generations. The independent and not-for-profit research institute the Sax Institute launched the 18 and Up study on Thursday to follow participants aged 18 to 45 throughout their lives, targeting major health challenges such as mental illness and rising cancer rates.
Building on Two Decades of Population Research
The new initiative follows the institute’s 45 and Up study, which began two decades ago and currently stands as the largest population-based cohort study in the southern hemisphere. That established program has enrolled more than 267,000 participants aged 45 to over 100. Data from the older cohort has been repeatedly surveyed and linked to other datasets, enabling discoveries about smoking, dementia prevention, and cardiovascular outcomes between men and women.
Professor Emily Banks, an epidemiologist and public health expert at the Australia National University and a former scientific director at the Sax Institute, used data from the 45 and Up study to reveal in 2025 that smoking-related illnesses kill 66 Australians daily. Banks noted that large-scale cohort studies give researchers a vital window into population exposures, serving as a collaborative resource utilized by more than 800 researchers worldwide.
Addressing Rising Rates of Mental Illness and Early-Onset Cancer
The scientific director of the 18 and Up study, Adjunct Prof Justine Gatt, stated that researchers lack long-term data for younger cohorts, as existing studies typically rely on single snapshots in time. Gatt pointed out that almost two in five young Australians aged 16 to 24 experienced a mental disorder in the past year, while suicide remains the leading cause of death among Australians aged 15 to 44.
The CEO of the Sax Institute, Dr Martin McNamara, explained that initial surveys will also focus on cancer rates. Since 2000, Australia and other regions have recorded an increase in early-onset cancers—diagnosed after adolescence but before age 50—which includes bowel, thyroid, and breast cancers. Scientists suspect increased screening, changing lifestyles, and early-life risk factors contribute to the trend, though researchers have called for urgent research to clarify these influences.
Funding, Recruitment, and Methodology
The 18 and Up study is backed by a $4.5m National Health and Medical Research Council grant, with recruitment scheduled to begin in November. Participants will be asked about their health, lifestyle, social circumstances, and background. With participant consent, this data will be linked to health records such as Medicare and cancer registries.
To capture intergenerational effects, researchers will invite the children and grandchildren of existing 45 and Up participants to join. This design aims to show how health is shaped by family history, lived experiences, and social conditions across generations. The project will adapt to participants over time with age-relevant questions, factoring in emerging health conditions and pandemics.
Frequently Asked Questions About the 18 and Up Study
Who is eligible to participate in the 18 and Up study?
The study recruits individuals aged 18 to 45, and also invites the children and grandchildren of participants from the established 45 and Up study to join.
When does recruitment for the new cohort begin?
Recruitment for the 100,000 participants officially begins in November, supported by a $4.5m National Health and Medical Research Council grant.
What specific health records will be linked to survey responses?
With participant consent, researchers will link survey data regarding lifestyle and background to health records including Medicare and cancer registries.
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