Previous meta-analyses of a small number of trials showed that acceptance and commitment therapy (ACT) might improve chronic pain. Many new trials have been published afterward, and the factors that may impact the efficacy of ACT are less understood. We, therefore, conducted an updated systematic review with meta-analysis to investigate the efficacy of ACT for people with chronic pain.

Randomized controlled trials that investigated the efficacy of ACT in clinical or community setting for adult populations with chronic pain were included. The methodological quality of trials was assessed with the Cochrane Risk of Bias tool. Standardized mean differences between ACT and comparison groups in their effects on 6 outcomes (ie, pain acceptance, quality of life, pain-related functioning, pain intensity, anxiety, and depression) were pooled across studies.

Of the 3171 records identified, 21 trials with 1962 participants were included for analysis. The comparison groups included active treatment and waitlist control/usual care. The standardized mean difference was 0.67 (95% CI: 0.48, 0.87) for pain acceptance, 0.43 (95% CI: 0.29, 0.57) for quality of life, −0.88 (95% CI: −1.14, −0.63) for pain-related functioning, −0.45 (95% CI: −0.62, −0.27) for pain intensity, −0.35 (95% CI: −0.54, −0.15) for anxiety, and −0.74 (95% CI, −0.98, −0.50) for depression, all favoring ACT. Subgroup analyses showed that the effects were statistically significant across almost all subgroups and for some outcomes were greater in the trials conducted in people with a specific diagnosis (as compared with those conducted in people with general chronic pain), the trials with waitlist or usual care control, the trials with a greater number of sessions of ACT, and the trials with a longer ACT intervention.

ACT is effective and comparable to, if not better than, some other available active treatments for chronic pain.