JMIR Publications

ABSTRACT

Background:

Acceptance and commitment therapy (ACT) is based on a psychological flexibility model encompassing 6 processes, including acceptance, cognitive defusion, self-as-context, being present, values, and committed action.

Objective:

This systematic review and meta-analysis of randomized controlled trials (RCTs) examined effects of internet-based ACT (iACT) on process measures.

Methods:

A comprehensive search was conducted within four databases. The quality of the included RCTs was assessed using the Cochrane Collaboration risk of bias tool. Either a random-effects model or a fixed-effects model was used. Subgroup analyses for each outcome were conducted according to the type of control groups, the use of therapist guidance, delivery modes, and the use of targeted participants, when applicable.

Results:

Thirty-four RCTs met the eligibility criteria. Meta-analysis found iACT had a medium effect on psychological flexibility and small effects on mindfulness, valued living, and cognitive deRelatively fewer studies were conducted to compare the effects of iACT to active control groups and to measure the effects on mindfulness, valued living, and cognitive defusion. These synthesized findings support the processes of change in iACT, which mental health practitioners can use to support the use of iACT. fusion at the immediate posttest. Also, iACT had a small effect on psychological flexibility at follow-up. The overall risk of bias across studies was unclear.

Conclusions:

Relatively fewer studies were conducted to compare the effects of iACT to active control groups and to measure the effects on mindfulness, valued living, and cognitive defusion. These synthesized findings support the processes of change in iACT, which mental health practitioners can use to support the use of iACT.