The Sax Institute on Thursday launched the 18 and Up study, recruiting 100,000 people aged 18 to 45 for Australia’s largest intergenerational study of wellbeing and ageing to examine major health challenges like mental illness and rising cancer rates.
Did You Know? Two decades ago, the Sax Institute started the 45 and Up study, which has since grown into the largest population-based cohort study in the southern hemisphere with more than 267,000 participants aged 45 to older than 100.
The Sax Institute Launches 18 and Up Study
The independent and not-for-profit research institute designed the new initiative to track the health of participants throughout their lives. Researchers noted a distinct lack of long-term data for younger demographics. Existing studies frequently offer only a temporary snapshot rather than continuous tracking.
Adjunct Professor Justine Gatt, scientific director of the new project, pointed out that nearly two in five young Australians aged 16 to 24 experienced a mental disorder in the past year. Gatt, who works as a neuroscientist and mental health researcher, emphasized that the rising figures lack the necessary long-term evidence to explain their underlying causes. Suicide is the leading cause of death among Australians aged 15 to 44, creating an urgent demand for better prevention strategies and treatments.
Family History and Early-Onset Cancers in Focus
The project will invite children and grandchildren of existing 45 and Up participants to join. Gatt explained that this intergenerational approach helps investigators analyze how family history, lived experiences, and social conditions interact across generations.
Dr. Martin McNamara, chief executive of the Sax Institute, stated that cancer questions will also form a core component of the initial surveys. Since 2000, medical observers have recorded an increase in early-onset cancers—defined as diagnoses occurring beyond adolescence but before the age of 50—including bowel, thyroid, and breast cancers in Australia and globally. Scientists point to increased screening, changing lifestyles, and early-life risk factors as potential contributors.
Participants will complete surveys covering their health, lifestyle, social circumstances, and background. With explicit consent, researchers will link these survey responses to external health registries and records, including Medicare and cancer registries.
Grants fund upcoming participant recruitment
The National Health and Medical Research Council provided a $4.5m grant to fund the initiative, with official participant recruitment scheduled to begin in November. The project framework is built to evolve alongside participants by introducing age-appropriate questions and adapting to emerging health conditions or future pandemics.
Emily Banks, a professor of epidemiology and public health at the Australian National University and former scientific director at the Sax Institute, highlighted the immense value of large-scale tracking. Banks utilized data from the older 45 and Up cohort for a 2025 study revealing that smoking-related illnesses claim 66 Australian lives every day. She noted that more than 800 researchers worldwide have relied on the older cohort data, which encompasses roughly 10 percent of New South Wales residents in that age group.
For individuals seeking support in Australia, assistance is available through Beyond Blue at 1300 22 4636, Lifeline at 13 11 14, and MensLine at 1300 789 978.
Who can join the new study
Who is eligible to join the 18 and Up study?
The study is open to individuals aged 18 to 45, specifically including the children and grandchildren of participants from the institute’s previous 45 and Up cohort.
What specific health issues will the study examine first?
Initial surveys will focus heavily on understanding the drivers behind mental health challenges and rising rates of early-onset cancers, such as bowel, thyroid, and breast cancers.
How is the project funded and when does recruitment start?
The initiative is funded by a $4.5m National Health and Medical Research Council grant, with recruitment set to begin in November.
How might linking lifestyle surveys directly with Medicare and cancer registries change the way public health officials respond to emerging generational health trends?
Related reading