title: Acceptance and Commitment Therapy modules: Differential impact on treatment processes and outcomes.
abstract: A modular, transdiagnostic approach to treatment design and implementation may increase the public health impact of evidence-based psychosocial interventions. Such an approach relies on algorithms for selecting and implementing treatment components intended to have a specific therapeutic effect, yet there is little evidence for how components function independent of their treatment packages when employed in clinical service settings. This study aimed to demonstrate the specificity of treatment effects for two components of Acceptance and Commitment Therapy (ACT), a promising candidate for modularization. A randomized, nonconcurrent, multiple-baseline across participants design was used to examine component effects on treatment processes and outcomes in 15 adults seeking mental health treatment. The ACT OPEN module targeted acceptance and cognitive defusion; the ACT ENGAGED module targeted values-based activation and persistence. According to Tau-U analyses, both modules produced significant improvements in psychiatric symptoms, quality of life, and targeted therapeutic processes. ACT ENGAGED demonstrated greater improvements in quality of life and values-based activation. ACT OPEN showed greater improvements in symptom severity, acceptance, and defusion. Both modules improved awareness and non-reactivity, which were mutually targeted, though using distinct intervention procedures. Both interventions demonstrated high treatment acceptability, completion, and patient satisfaction. Treatment effects were maintained at 3-month follow up. ACT components should be considered for inclusion in a modular approach to implementing evidence-based psychosocial interventions for adults.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, USA. Electronic address: villatte@uw.edu.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Villatte
authors.affiliation: Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, USA. Electronic address: vilardag@uw.edu.
authors.forename: Roger
authors.initials: R
authors.lastname: Vilardaga
authors.affiliation: Evidence Based Practice Institute, Seattle, WA, USA. Electronic address: matt@ebpi.org.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Villatte
authors.affiliation: Veterans Affairs Puget Sound Health Care System, Seattle Division, Seattle, WA, USA. Electronic address: jennifer.plumbvilardaga@va.gov.
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Plumb Vilardaga
authors.affiliation: Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, USA. Electronic address: datkins@uw.edu.
authors.forename: David C
authors.initials: DC
authors.lastname: Atkins
authors.affiliation: Department of Psychology, University of Nevada, Reno, USA. Electronic address: hayes@unr.edu.
authors.forename: Steven C
authors.initials: SC
authors.lastname: Hayes
mesh_terms: D064869:Acceptance and Commitment Therapy / Q000379:methods* / Q000592:standards; D000328:Adult; D001364:Awareness; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000628:therapy*; D008875:Middle Aged; D064866:Mindfulness; D017060:Patient Satisfaction; D011613:Psychotherapy; D011788:Quality of Life / Q000523:psychology; D012720:Severity of Illness Index; D016896:Treatment Outcome
keywords: Acceptance; Acceptance and commitment therapy; Component analysis; Mindfulness; Modular design; Single case experimental design; Therapy process; Values