TY - JOUR T1 - Examining the Impact of the Incredible Years Parenting Program: A Systematic Review of Randomized Controlled Trials in Early Childhood TT - Eşsiz Yıllar Ebeveynlik Programının Etkililiğinin İncelenmesi: Erken Çocuklukta Yürütülen Randomize Kontrollü Çalışmaların Sistematik Derlemesi AU - Kuru, Nilüfer PY - 2025 DA - June Y2 - 2025 DO - 10.58667/sedder.1705511 JF - Siirt Eğitim Dergisi JO - SED PB - Siirt Üniversitesi WT - DergiPark SN - 2791-870X SP - 45 EP - 61 VL - 5 IS - 1 LA - en AB - The Incredible Years (IY) parenting program is an intervention that has been widely implemented to improve parenting practices and child development. This systematic review examined randomized controlled trials (RCTs) that assessed the effectiveness of IY programs for children aged 0–8 and their caregivers. A comprehensive literature search was conducted in the Web of Science, PsycINFO, and ERIC databases for studies published between 2021 and 2025. Inclusion criteria required an RCT design and implementation of the IY parenting program with parents of children under eight. The review followed PRISMA guidelines. Eleven eligible studies were included. The findings showed consistent reductions in children's externalizing behaviors and improvements in parenting strategies. Several studies also reported positive changes in children’s emotional regulation, developmental outcomes, and caregivers' psychological well-being. Some trials examined biological indicators, such as DNA methylation, which suggests preliminary evidence of physiological benefits. However, effects based on teacher reports and observational tools were less consistent. The Incredible Years program appears to be an effective intervention for enhancing behavioral and developmental outcomes in children and improving parental well-being. It is a promising intervention for promoting early childhood mental health, though further research is needed on its long-term and biological impacts KW - Incredible Years KW - parenting program KW - early childhood KW - randomized controlled trial KW - psychosocial outcomes N2 - The Incredible Years (IY) parenting program is an intervention that has been widely implemented to improve parenting practices and child development. This systematic review examined randomized controlled trials (RCTs) that assessed the effectiveness of IY programs for children aged 0–8 and their caregivers. A comprehensive literature search was conducted in the Web of Science, PsycINFO, and ERIC databases for studies published between 2021 and 2025. Inclusion criteria required an RCT design and implementation of the IY parenting program with parents of children under eight. The review followed PRISMA guidelines. Eleven eligible studies were included. The findings showed consistent reductions in children's externalizing behaviors and improvements in parenting strategies. Several studies also reported positive changes in children’s emotional regulation, developmental outcomes, and caregivers' psychological well-being. Some trials examined biological indicators, such as DNA methylation, which suggests preliminary evidence of physiological benefits. However, effects based on teacher reports and observational tools were less consistent. The Incredible Years program appears to be an effective intervention for enhancing behavioral and developmental outcomes in children and improving parental well-being. It is a promising intervention for promoting early childhood mental health, though further research is needed on its long-term and biological impacts CR - Arruabarrena, I., Rivas, G. R., Cañas, M., & De Paúl, J. (2022). The Incredible Years Parenting and Child Treatment Programs: A randomized controlled trial in a child welfare setting in Spain. Psychosocial Intervention, 31(1), 43. https://doi.org/10.5093/pi2022a2 CR - Blower, S. L., Berry, V. L., Bursnall, M. C., Cohen, J., Gridley, N., Loban, A., ... & Bywater, T. J. (2021). Enhancing social-emotional outcomes in early years (E-SEE): randomized pilot study of incredible years infant and toddler programs. Journal of Child and Family Studies, 30(8), 1933- 1949. https://doi.org/10.1007/s10826-021-01991-7 CR - Bywater, T., Berry, V., Blower, S., Bursnall, M., Cox, E., Mason-Jones, A., ... & Whittaker, K. (2022). A randomized controlled trial of a proportionate universal parenting program delivery model (ESEE Steps) to enhance child social-emotional wellbeing. PLoS One, 17(4), e0265200. https://doi.org/10.1371/journal.pone.0265200 CR - Creasey, N., Leijten, P., Overbeek, G., & Tollenaar, M. S. (2024a). Incredible years parenting program buffers prospective association between parent-reported harsh parenting and epigenetic age deceleration in children with externalizing behavior. Psychoneuroendocrinology, 165, 107043. https://doi.org/10.1016/j.psyneuen.2024.107043 CR - Creasey, N., Leijten, P., Tollenaar, M. S., Boks, M. P., & Overbeek, G. (2024b). DNA methylation variation after a parenting program for child conduct problems: Findings from a randomized controlled trial. Child Development, 95(5), 1462-1477. https://doi.org/10.1111/cdev.14090 CR - Danbolt, A. M. V. (2020). Cultural responsiveness in the Incredible Years parenting programme for refugees: a case study. International Journal of Child Care and Education Policy, 14(1), 6. https://doi.org/10.1186/s40723-020-00071-5 CR - Edwards, R. T., Jones, C., Berry, V., Charles, J., Linck, P., Bywater, T., & Hutchings, J. (2016). Incredible Years parenting programme: cost-effectiveness and implementation. Journal of Children's Services, 11(1), 54-72. https://doi.org/10.1108/JCS-02-2015-0005 CR - Furlong, M., & McGilloway, S. (2012). The Incredible Years Parenting program in Ireland: A qualitative analysis of the experience of disadvantaged parents. Clinical Child Psychology and Psychiatry, 17(4), 616-630. https://doi.org/10.1177/1359104511426406 CR - Gardner, F., & Leijten, P. (2017). Incredible Years parenting interventions: Current effectiveness research and future directions. Current Opinion in Psychology, 15, 99-104. https://doi.org/10.1016/j.copsyc.2017.02.023 CR - Gardner, F., Leijten, P., Harris, V., Mann, J., Hutchings, J., Beecham, J., ... & Landau, S. (2019). Equity effects of parenting interventions for child conduct problems: a pan-European individual participant data meta-analysis. The Lancet Psychiatry, 6(6), 518-527. CR - Huijzer-Engbrenghof, M., van Rijn-van Gelderen, L., van den Akker, A., Jorgensen, T. D., & Overbeek, G. (2023). Intervention-induced temperament changes in children: Evidence from a randomized controlled trial of the Incredible Years parent program. Developmental Psychology, 59(10), 1839. https://doi.org/10.1037/dev0001591 CR - Jones, C. H., Erjavec, M., Viktor, S., & Hutchings, J. (2016). Outcomes of a comparison study into a group-based infant parenting programme. Journal of Child and Family Studies, 25, 3309-3321. https://doi.org/10.1007/s10826-016-0489-3 CR - Karjalainen, P., Kiviruusu, O., Aronen, E. T., & Santalahti, P. (2019). Group-based parenting program to improve parenting and children's behavioral problems in families using special services: A randomized controlled trial in a real-life setting. Children and Youth Services Review, 96, 420- 429. https://doi.org/10.1016/j.childyouth.2018.12.004 CR - Karjalainen, P., Santalahti, P., Aronen, E. T., & Kiviruusu, O. (2021). Parent-and teacher-reported longterm effects of parent training on child conduct problems in families with child protection and other support services: a randomized controlled trial. Child and Adolescent Psychiatry and Mental Health, 15, 1-14. https://doi.org/10.1186/s13034-021-00358-6 CR - Leijten, P., Gardner, F., Landau, S., Harris, V., Mann, J., Hutchings, J., ... & Scott, S. (2018). Research review: Harnessing the power of individual participant data in a meta‐analysis of the benefits and harms of the incredible years parenting program. Journal of Child Psychology and Psychiatry, 59(2), 99-109. https://doi.org/10.1111/jcpp.12781 CR - Leijten, P., Raaijmakers, M. A., Orobio de Castro, B., van den Ban, E., & Matthys, W. (2017). Effectiveness of the Incredible Years parenting program for families with socioeconomically disadvantaged and ethnic minority backgrounds. Journal of Clinical Child & Adolescent Psychology, 46(1), 59-73. https://doi.org/10.1080/15374416.2015.1038823 CR - Leitão, S. M., Francisco, R., Seabra‐Santos, M. J., & Gaspar, M. F. (2024). The process in‐between: Parents' perceptions about how practitioners promote the outcomes of the Incredible Years Basic program. Family Process, 63(4), 1867-1886. https://doi.org/10.1111/famp.13018 CR - Lobo, F. M., & Lunkenheimer, E. (2020). Understanding the parent-child coregulation patterns shaping child self-regulation. Developmental Psychology, 56(6), 1121. https://doi.org/10.1037/dev0000926 CR - Masiran, R., Ibrahim, N., Awang, H., & Ying Lim, P. (2022). Changes in prosocial behaviors among children with behavioral problems following Incredible Years Parenting Program. Frontiers in Psychology, 13, 847722. https://doi.org/10.3389/fpsyg.2022.847722 CR - Menting, A. T., de Castro, B. O., & Matthys, W. (2013). Effectiveness of the Incredible Years parent training to modify disruptive and prosocial child behavior: A meta-analytic review. Clinical Psychology Review, 33(8), 901-913. https://doi.org/10.1016/j.cpr.2013.07.006 CR - Mooney, K. E., Bywater, T., Hinde, S., Richardson, G., Wright, J., Dickerson, J., & Blower, S. L. (2023). A quasi-experimental effectiveness evaluation of the Incredible Years Toddler parenting programme on children’s development aged 5: A study protocol. PLoS One, 18(9), e0291557. https://doi.org/10.1371/journal.pone.0291557 CR - Moher, D., Liberati, A., Tetzlaff, J., & Altman, D. G. (2009). Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. Bmj, 339. https://doi.org/10.1136/bmj.b2535 CR - Morpeth, L., Blower, S., Tobin, K., Taylor, R. S., Bywater, T., Edwards, R. T., ... & Berry, V. (2017). The effectiveness of the Incredible Years pre-school parenting programme in the United Kingdom: a pragmatic randomised controlled trial. Child Care in Practice, 23(2), 141-161. https://doi.org/10.1080/13575279.2016.1264366 CR - Ouzzani, M., Hammady, H., Fedorowicz, Z., & Elmagarmid, A. (2016). Rayyan—a web and mobile app for systematic reviews. Systematic Reviews, 5, 1-10. https://doi.org/10.1186/s13643-016- 0384-4 CR - Pidano, A. E., & Allen, A. R. (2015). The Incredible Years series: A review of the independent research base. Journal of Child and Family Studies, 24, 1898-1916. https://doi.org/10.1007/s10826-014- 9991-7 CR - Pontoppidan, M., Sandoy, T. M., & Klest, S. K. (2020). One-year follow-up of The Incredible Years Parents and Babies Program: A pilot randomized controlled trial. Scandinavian Journal of Child and Adolescent Psychiatry and Psychology, 8, 123. https://doi.org/10.21307/sjcapp-2020-012 CR - Pontoppidan, M., Thorsager, M., & Steenhoff, T. (2022). Parent-child relationship outcomes of the Incredible Years Parents and Babies Program: A pilot randomized controlled trial. Scandinavian Journal of Child and Adolescent Psychiatry and Psychology, 10(1), 40. https://doi.org/10.2478/sjcapp-2022-0004 CR - Rutter, M., Kim‐Cohen, J., & Maughan, B. (2006). Continuities and discontinuities in psychopathology between childhood and adult life. Journal of Child Psychology and Psychiatry, 47(3‐4), 276-295. https://doi.org/10.1111/j.1469-7610.2006.01614.x CR - Scott, S., Knapp, M., Henderson, J., & Maughan, B. (2001). Financial cost of social exclusion: Followup study of antisocial children into adulthood. BMJ, 323(7306), 191. https://doi.org/10.1136/bmj.323.7306.191 CR - Serrano, M., Elias, M., Llorens, M., Bolasell, M., Vall-Roqué, H., & Villalta, L. (2024). Early treatment for children with mental health problems and genetic conditions through a parenting intervention (The GAP): Study protocol for a pragmatic randomized controlled trial. Trials, 25(1), 496. https://doi.org/10.1186/s13063-024-08278-4 CR - Shaw, D. S., & Gross, H. E. (2008). What we have learned about early childhood and the development of delinquency. In The long view of crime: A synthesis of longitudinal research (pp. 79–127). New York, NY: Springer. CR - Webster-Stratton, C. (2011). The Incredible Years parents, teachers, and children’s training series: Program content, methods, research and dissemination 1980–2011. Seattle, WA: Incredible Years Inc. CR - Webster-Stratton, C., Hibbs, E. D., & Jensen, P. S. (2005). The Incredible Years: A training series for the prevention and treatment of conduct problems in young children. In Vol. 2nd, pp. 507–555. Washington, DC: American Psychological Association. CR - Weeland, J., Brummelman, E., Jaffee, S. R., Chhangur, R. R., Van der Giessen, D., Matthys, W., ... & Overbeek, G. (2022). Does caregivers’ use of praise reduce children’s externalizing behavior? A longitudinal observational test in the context of a parenting program. Developmental Psychology, 58(7), 1371. https://doi.org/10.1037/dev0001357 CR - Weeland, J., Leijten, P., Orobio de Castro, B., Menting, A., Overbeek, G., Raaijmakers, M., ... & Matthys, W. (2023). Exploring parenting profiles to understand who benefits from the Incredible Years Parenting Program. Prevention Science, 24(2), 259-270. https://doi.org/10.1007/s11121- 022-01364-6 CR - Valencia, F., Urbiola, E., Romero-González, M., Navas, I., Elías, M., Garriz, A., ... & Villalta, L. (2021). Protocol for a randomized pilot study (FIRST STEPS): Implementation of the Incredible YearsASLD® program in Spanish children with autism and preterm children with communication and/or socialization difficulties. Trials, 22, 1–10. https://doi.org/10.1186/s13063-021-05229-1 UR - https://doi.org/10.58667/sedder.1705511 L1 - https://dergipark.org.tr/tr/download/article-file/4898193 ER -