Assessment & Research

Evaluating the Open and Engaged Components of Acceptance and Commitment Therapy in an Online Self-Guided Website: Results from a Pilot Trial.

Petersen et al. (2021) · Behavior modification 2021
★ The Verdict

Online ACT still works, and the four-skill combo gives the best bang for zero clinic time.

✓ Read this if BCBAs adding telehealth mental-health tools for anxious or depressed adults.
✗ Skip if Clinicians who only serve clients without internet access.

01Research in Context

01

What this study did

Researchers built a free, self-guided website with three ACT tracks.

Track one taught acceptance and defusion (Open).

Track two taught values and committed action (Engaged).

Track three packed all four skills together (Combined).

Adults with anxiety or depression were randomly picked for one track.

Everyone logged in from home for six weeks.

02

What they found

All three tracks cut distress and boosted psychological flexibility.

The combined track edged out the single tracks on quality-of-life scores.

Effect sizes were medium, not huge.

Drop-out was low, showing people will stick with online ACT.

03

How this fits with other research

Plant et al. (2007) first showed face-to-face ACT equals standard cognitive therapy.

The new study keeps those gains while removing the therapist room.

Anonymous (2024) also found online parent training works as well as in-person.

Together these papers build a rule: behavioral help can travel through a screen without losing punch.

Tyndall et al. (2020) sorted clients into low, middle, and high flexibility profiles.

That work hints the combined ACT module may help the low-flexibility group most, something the 2021 trial did not test directly.

04

Why it matters

You can now assign ACT homework that runs itself.

Pick the combined module when you want maximum skill coverage in little time.

Track flexibility with a quick survey first; send the low-scorers straight to the full package.

No extra staff, no travel, still solid gains.

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→ Action — try this Monday

Email a client the link to the free combined ACT module and set a daily login goal.

02At a glance

Intervention
other
Design
randomized controlled trial
Sample size
55
Population
mixed clinical
Finding
positive
Magnitude
medium

03Original abstract

Online acceptance and commitment therapy (ACT) is promising for treating a range of psychological problems. Component research can further clarify which components are needed for optimal outcomes in what contexts. Online platforms provide a highly controlled format for such research. In this pilot trial, 55 adults were randomized to: ACT-Open (i.e., acceptance, defusion components), ACT-Engaged (i.e., values, committed action), or ACT-Combined (i.e., acceptance, defusion, values, committed action). Each condition was 12 sessions over 6 weeks, with assessments at baseline, post-treatment, and 4-week follow-up. ACT-Open, ACT-Engaged, and ACT-Combined all significantly improved from pre- to post-treatment on mental health, psychosocial functioning, and components of psychological flexibility. Compared to ACT-Combined, ACT-Open improved less on psychosocial functioning at post-treatment, and ACT-Engaged worsened on functioning at follow-up. The platform was acceptable with high satisfaction ratings. Results support the feasibility of conducting online ACT component research, which will be tested in a fully powered non-inferiority trial.

Behavior modification, 2021 · doi:10.1177/0145445519878668