Supporting loving and secure relationships keeping our children in mind


For further information on the suite of Incredible Years Programmes:

Effectiveness of the Incredible Years Parent Training to Modify Disruptive and Prosocial Child Behavior: A Meta-Analytic Review

Reference: Mentinga, A.T.A., Orobio de Castro, B. and Matthys, W. 2013. Clinical Psychology Review.

Findings indicate that the IYPT is successful in improving child behaviour in a diverse range of families, and that the parent programme may be considered well-established.

Evaluation Studies and Design

  • The Incredible Years Parent Training Programmes were first recommended by the American Psychological Association Task Force (Brestan & Eyberg, 1998) as meeting the stringent “Chambless & Hollon criteria” (1998) for empirically supported mental health intervention for children with conduct problems.
  • Chambless, D.L. and Hollon, S.D. (1998). Defining Empirically Supported Therapies. Journal of Consulting and Clinical Psychology, 66, 7–18.
  • Brestan, E.V. & Eyberg, S.M. (1998). Effective psychosocial treatments of conduct-disordered children and adolescents; 29 years, 82 studies, and 5,272 kids. Journal of Clinical Psychology, 27, 180–189.
  • In the last decade, the Incredible Years programmes have been given designations such as: “Exemplary”, “Promising”, “Proven” and “Model” in review groups such as OJJDP, SAMHSA’s NREPP, Promising Practices Network, Blueprints for Health Youth Development and United Nations Office on Drugs and Crime. Typically, these review groups require the following to be classified as evidence-based: (1) statistical significance in at least two randomised control group trials using reliable and valid outcome assessment measures; and (2) replications by an independent evaluator.

Incredible Years follow-up study: Long-term follow-up of the New Zealand Incredible Years Pilot Study

Reference: Strurrock, F., et al., Incredible Years Follow-up Study, Ministry of Social Development, 2014. 

  • The key finding of the follow-up study is that the IVP programme outcomes were maintained over the 30-month follow-up with no diminution in the size of effects for almost all of the outcome measures.
  • As part of the Drivers of Crime work programme the Ministries of Education, Health and Social Development established a pilot study of the Incredible Years Parent (IYP) programme to assess its effectiveness in reducing conduct problems in a New Zealand context.
  • The New Zealand Incredible Years Pilot Study provided evidence to suggest that IYP, a programme developed overseas, can be successfully implemented in New Zealand and retain its general level of effectiveness for both Māori and non-Māori families.
  • The follow-up study investigated the long-term outcomes for 136 (82%) of the 166 children and parents who were in the original sample.