The Child to Adult Transition Study (CATS)

CATS is a unique longitudinal study of children in metropolitan Melbourne as they transition through adolescence and into adulthood.

The study began in 2012 and follows over 1200 children from grade 3 (8-9 years of age) through adolescence and into adulthood. The young people are assessed once every year. The study also collected information from teachers through primary school, and parents through to year 8 (13-14 years) then again in year 11 (16-17 years). The main focus of the study is on the health and emotional development of young people during the middle years (8-14 years) and through the primary to secondary transition. The study aims to improve our understanding of the many influences that the effect the health and emotional adjustment of children as they traverse late childhood and adolescence. The study looks at the experiences of children and their families, their changing social context as they move through secondary school and beyond, and their reactions to the biological changes of puberty. The information collected as part of this large study will help us identify when and how to promote the best health and emotional adjustment in young people.

The CATS cohort are currently transitioning out of high school after completing their final two years of schooling during the COVID 19 pandemic. CATS plans to follow this important group of young people as they enter the workforce or begin further education in a COVID-19 world. With eight waves of data collection pre-pandemic, the study is ideally placed to investigate the impact of the pandemic on this new generation of young Australians.

Study Summary
Study name Child to Adult Transition Study
Study abbreviation CATS
Current principal investigator/s Professor Susan Sawyer
Current project manager

Carolina Murphy

Primary Institution/s Murdoch Children’s Research Institute - MCRI
Collaborating Institution/s The University of Melbourne - UoM
University of South Australia
University of New South Wales
University College London Institute of Child Health, UK - UCL
La Trobe University
Major funding source/s National Health and Medical Research Council - NHMRC
Study website
Key reference for study Mundy, L.K., Simmons, J.G., Allen, N.B., Viner, R.M., Bayer, J.K., Olds, T., Williams, J., Olsson, C., Romaniuk, H., Mensah, F., Sawyer, S.M., Degenhardt, L., Alati, R., Wake, M., Jacka, F. and Patton, G.C.. Study protocol: the Childhood to Adolescence Transition Study (CATS). BMC Pediatr. 2013 Oct 8;13:160. doi: 10.1186/1471-2431-13-160
Study focus

The health and emotional development of children as they pass through puberty and the middle years of school, to improve the understanding of the many influences that effect the health and emotional adjustment during these transition years

Sampling frame

All Grade 3 students (8-9 years of age) from a stratified cluster sample of schools in Melbourne, Australia were invited to take part.

Primary study type Longitudinal cohort
Primary participant (at recruitment) Index child
Year commenced


Is this study ongoing? Yes - the study is ongoing
Ongoing recruitment? No
Sample size (N)


Survey data available? Yes
Imaging data available? Yes
Linkage to administrative dataset/s? Yes, linkage to (at least one) administrative dataset completed
Biosamples available? Yes
Are data available to others outside study team, with appropriate safeguards and structures in line with the cohort’s ethics and governance processes? Yes
Are there any costs associated with data/sample access for approved requests? There are usually no costs associated with access
Broadest type of participant consent available Extended consent (can be used for future ethically approved research related to this project)
Wave Year Age Sample size (N)
1 2012 8-9 years N(Total)=1239
2 2013 9-10 years N(Total)=1158
3 2014 10-11 years N(Total)=1119
4 2015 11-12 years N(Total)=1066
5 2016 12-13 years N(Total)=1175
6 2017 13-14 years N(Total)=1177
7 2018 14-15 years N(Total)=1137
8 2019 15-16 years N(Total)=1102
9 2020 16-17 years N(Total)=1084
10 2021 17-18 years


Mundy LK, Canterford L, Moreno‐Betancur M, Hoq M, Viner RM, Bayer JK, Lietz P, Redmond G, Patton GC. (2022). Learning outcomes in primary school children with emotional problems: a prospective cohort study Child and Adolescent Mental Health. DOI: 10.1111/camh.12607


Borschmann R, Mundy L, Canterford L, Moreno-Betancur M, Moran P, Allen N, Viner R, Degenhardt L, Kosola S, Fedyszyn I, Patton G. (2021). 533The psychosocial profiles of children aged 11-12 years who have self-harmed: A prospective cohort study International Journal of Epidemiology, 50(Supplement_1). DOI: 10.1093/ije/dyab168.090

Goddings A-L, Viner RM, Mundy L, Romaniuk H, Molesworth C, Carlin JB, Allen NB, Patton GC. (2021). Growth and adrenarche: findings from the CATS observational study Archives of Disease in Childhood, 106(10), 967 - 974. DOI: 10.1136/archdischild-2020-319341


Andreucci A, Campbell P, Mundy LK, Sawyer SM, Kosola S, Patton GC, Dunn KM. (2020). Sleep problems increase the risk of musculoskeletal pain in boys but not girls: a prospective cohort study European Journal of Pediatrics, 179(11), 1711 - 1719. DOI: 10.1007/s00431-020-03667-8

Borschmann R, Mundy LK, Canterford L, Moreno-Betancur M, Moran PA, Allen NB, Viner RM, Degenhardt L, Kosola S, Fedyszyn I, Patton GC. (2020). Self-harm in primary school-aged children: Prospective cohort study PLOS ONE, 15(11), e0242802. DOI: 10.1371/journal.pone.0242802

Fujikawa S, Mundy LK, Canterford L, Moreno-Betancur M, Patton GC. (2020). Bullying Across Late Childhood and Early Adolescence: A Prospective Cohort of Students Assessed Annually From Grades 3 to 8 Academic Pediatrics, 21(2), 344 - 351. DOI: 10.1016/j.acap.2020.10.011

Mundy LK, Canterford L, Hoq M, Olds T, Moreno-Betancur M, Sawyer S, Kosola S, Patton GC. (2020). Electronic media use and academic performance in late childhood: A longitudinal study PLOS ONE, 15(9), e0237908. DOI: 10.1371/journal.pone.0237908

Mundy LK, Canterford L, Moreno‐Betancur M, Hoq M, Sawyer SM, Allen NB, Patton GC. (2020). Social networking and symptoms of depression and anxiety in early adolescence Depression and Anxiety, 38(5), 563 - 570. DOI: 10.1002/da.23117


Dimov S, Mundy LK, Bayer JK, Jacka FN, Canterford L, Patton GC. (2019). Diet quality and mental health problems in late childhood Nutritional Neuroscience, 24(1), 62 - 70. DOI: 10.1080/1028415x.2019.1592288

Ellis R, Fernandes A, Simmons JG, Mundy L, Patton G, Allen NB, Whittle S. (2019). Relationships between adrenarcheal hormones, hippocampal volumes and depressive symptoms in children Psychoneuroendocrinology, 104, 55 - 63. DOI: 10.1016/j.psyneuen.2019.02.016


Barbosa C, Simmons JG, Vijayakumar N, Dudgeon P, Patton GC, Mundy LK, Allen NB, Whittle S. (2018). Interaction Between Parenting Styles and Adrenarcheal Timing Associated With Affective Brain Function in Late Childhood Journal of the American Academy of Child & Adolescent Psychiatry, 57(9), 678 - 686.e4. DOI: 10.1016/j.jaac.2018.05.016

Barendse MEA, Simmons JG, Byrne ML, Patton G, Mundy L, Olsson CA, Seal ML, Allen NB, Whittle S. (2018). Associations between adrenarcheal hormones, amygdala functional connectivity and anxiety symptoms in children Psychoneuroendocrinology, 97, 156 - 163. DOI: 10.1016/j.psyneuen.2018.07.020

Bayer JK, Mundy L, Stokes I, Hearps S, Allen N, Patton G. (2018). Bullying, mental health and friendship in Australian primary school children Child and Adolescent Mental Health, 23(4), 334 - 340. DOI: 10.1111/camh.12261

Hughes EK, Mundy LK, Romaniuk H, Sawyer SM, Wake M, Williams J, Olds T, Allen NB, Patton GC. (2018). Body Image Dissatisfaction and the Adrenarchal Transition Journal of Adolescent Health, 63(5), 621 - 627. DOI: 10.1016/j.jadohealth.2018.05.025


Byrne ML, Badcock PB, Simmons JG, Whittle S, Pettitt A, Olsson CA, Mundy LK, Patton GC, Allen NB. (2017). Self-Reported Parenting Style Is Associated With Children’s Inflammation and Immune Activation Journal of Family Psychology, 31(3), 374 - 380. DOI: 10.1037/fam0000254

Evans-Whipp T, Mundy L, Miller E, Canterford L, Patton G. (2017). The Effects on Schooling Outcomes of Early Developmental Vulnerabilities in Children .

Kosola S, Mundy LK, Sawyer SM, Canterford L, van der Windt DA, Dunn KM, Patton GC. (2017). Pain and learning in primary school Pain, 158(9), 1825 - 1830. DOI: 10.1097/j.pain.0000000000000984

Mundy LK, Canterford L, Kosola S, Degenhardt L, Allen NB, Patton GC. (2017). Peer Victimization and Academic Performance in Primary School Children Academic Pediatrics, 17(8), 830 - 836. DOI: 10.1016/j.acap.2017.06.012

Mundy LK, Canterford L, Tucker D, Bayer J, Romaniuk H, Sawyer S, Lietz P, Redmond G, Proimos J, Allen N, Patton G. (2017). Academic Performance in Primary School Children With Common Emotional and Behavioral Problems Journal of School Health, 87(8), 593 - 601. DOI: 10.1111/josh.12531


Mundy LK, Canterford L, Olds T, Allen NB, Patton GC. (2016). The Association Between Electronic Media and Emotional and Behavioral Problems in Late Childhood Academic Pediatrics, 17(6), 620 - 624. DOI: 10.1016/j.acap.2016.12.014


Delany FM, Byrne ML, Whittle S, Simmons JG, Olsson C, Mundy LK, Patton GC, Allen NB. (2015). Depression, immune function, and early adrenarche in children Psychoneuroendocrinology, 63, 228 - 234. DOI: 10.1016/j.psyneuen.2015.10.003

Mundy LK, Romaniuk H, Canterford L, Hearps S, Viner RM, Bayer JK, Simmons JG, Carlin JB, Allen NB, Patton GC. (2015). Adrenarche and the Emotional and Behavioral Problems of Late Childhood Journal of Adolescent Health, 57(6), 608 - 616. DOI: 10.1016/j.jadohealth.2015.09.001

Murray CR, Simmons JG, Allen NB, Byrne ML, Mundy LK, Seal ML, Patton GC, Olsson CA, Whittle S. (2015). Associations between dehydroepiandrosterone (DHEA) levels, pituitary volume, and social anxiety in children Psychoneuroendocrinology, 64, 31 - 39. DOI: 10.1016/j.psyneuen.2015.11.004

Simmons JG, Badcock PB, Whittle SL, Byrne ML, Mundy L, Patton GC, Olsson CA, Allen NB. (2015). The lifetime experience of traumatic events is associated with hair cortisol concentrations in community-based children Psychoneuroendocrinology, 63, 276 - 281. DOI: 10.1016/j.psyneuen.2015.10.004

Whittle S, Simmons JG, Byrne ML, Strikwerda-Brown C, Kerestes R, Seal ML, Olsson CA, Dudgeon P, Mundy LK, Patton GC, Allen NB. (2015). Associations between early adrenarche, affective brain function and mental health in children Social Cognitive and Affective Neuroscience, 10(9), 1282 - 1290. DOI: 10.1093/scan/nsv014


Klauser P, Whittle S, Simmons JG, Byrne ML, Mundy LK, Patton GC, Fornito A, Allen NB. (2014). Reduced frontal white matter volume in children with early onset of adrenarche Psychoneuroendocrinology, 52, 111 - 118. DOI: 10.1016/j.psyneuen.2014.10.020

Simmons JG, Whittle SL, Patton GC, Dudgeon P, Olsson C, Byrne ML, Mundy LK, Seal ML, Allen NB. (2014). Study protocol: Imaging brain development in the Childhood to Adolescence Transition Study (iCATS) BMC Pediatrics, 14(1), 115. DOI: 10.1186/1471-2431-14-115


Mundy LK, Simmons JG, Allen NB, Viner RM, Bayer JK, Olds T, Williams J, Olsson C, Romaniuk H, Mensah F, Sawyer SM, Degenhardt L, Alati R, Wake M, Jacka F, Patton GC. (2013). Study protocol: the Childhood to Adolescence Transition Study (CATS) BMC Pediatrics, 13(1), 160. DOI: 10.1186/1471-2431-13-160

Study Contacts
Principal investigator/s Professor Susan Sawyer
Project manager

Carolina Murphy

Study Contact

Phone: +61 3 9345 6732
Address: Murdoch Children's Research Institute,
Royal Children’s Hospital
Flemington Road, Parkville
Victoria 3052 Australia