In plain language
As Acceptance and Commitment Therapy (ACT) entered its 40th year, this paper looks back at how it and other “third wave” cognitive behavioral therapies developed, and asks what that history teaches us about the future of CBT and evidence-based therapy. The authors identify four features of ACT’s development strategy that paid off: universalism (methods meant to apply to everyone, not just the diagnosed), change processes that operate at multiple levels and dimensions and are linked to basic principles, idiographic (individual-focused) concepts and methods, and an evolutionary approach.
The central argument is that intervention science now needs to become “idionomic”: start with frequent, individual-level (idiographic) assessment, and only scale up to group-level (nomothetic) conclusions when doing so actually improves the fit for individuals. Traditional statistical approaches to studying change processes rest on mathematical assumptions — such as treating group averages as if they describe individuals — that cannot be met, and this has limited progress. To find candidate processes of change, the team also reviewed the world’s literature on mediation in randomized trials of psychological interventions: after screening nearly 55,000 studies, they identified 1,050 mediational findings across 624 studies, and 72 measures that successfully mediated intervention outcomes and were replicated.
The Extended Evolutionary Meta-Model (EEMM) can organize and summarize this body of findings, and new idionomic statistical methods can turn these processes into an empirical form of functional analysis tailored to an individual’s goals and needs. The payoff, the authors argue, is that process-based therapy frees intervention science from the unhelpful “latent disease” model and promises faster progress toward a unified, personalized science of human improvement.
Key findings
- Identifies four key features of ACT’s 40-year development strategy: universalism, multi-level and multi-dimensional processes linked to basic principles, idiographic concepts and methods, and an evolutionary approach.
- Argues that traditional methodological and statistical approaches to processes of change rest on mathematical assumptions that cannot be met, limiting progress in the field.
- Proposes a functional, idionomic approach: begin with frequent idiographic (individual-level) assessment, then scale to nomothetic (group-level) findings only when this improves idiographic fit.
- Systematically reviewed the world literature on mediators of psychological intervention outcomes, screening 54,633 studies and full-text reviewing 1,353 of them.
- Identified 1,050 mediational findings across 624 randomized studies, yielding 72 replicated measures that successfully mediated mental health intervention outcomes.
- Shows that the Extended Evolutionary Meta-Model (EEMM) can summarize this evidence, and concludes that process-based therapy frees intervention science from the latent disease model in favor of a unified, personalized science of human improvement.
How to cite
APA
Hayes, S. C., Ciarrochi, J., Hofmann, S. G., Chin, F., & Sahdra, B. (2022). Evolving an idionomic approach to processes of change: Towards a unified personalized science of human improvement. Behaviour Research and Therapy, 156, Article 104155. https://doi.org/10.1016/j.brat.2022.104155
BibTeX
@article{hayes2022evolving,
title = {Evolving an idionomic approach to processes of change: Towards a unified personalized science of human improvement},
author = {Hayes, Steven C. and Ciarrochi, Joseph and Hofmann, Stefan G. and Chin, Fredrick and Sahdra, Baljinder},
journal = {Behaviour Research and Therapy},
year = {2022},
volume = {156},
pages = {104155},
doi = {10.1016/j.brat.2022.104155}
}
Related work
- All publications by Joseph Ciarrochi (searchable, with free PDFs)
- Process-Based Therapy & Idionomic Analysis
- Process-Based Assessment Tool (PBAT) support site
Author: Joseph Ciarrochi (ORCID 0000-0003-0471-8100). Free copy hosted with permission for scholarly use. Please cite the published version via the DOI above.