Efficacy and mechanisms of internet-delivered mindfulness-based cognitive therapy for Adjustment Disorder: A randomized controlled trial.

BACKGROUND

Adjustment Disorder (AjD) is a common stress-related condition, yet evidence-based interventions remain scarce. Mindfulness-Based Cognitive Therapy (MBCT) targets transdiagnostic mechanisms such as cognitive fusion and low self-compassion, which may be particularly relevant for AjD.

OBJECTIVE

This randomized controlled trial tested the efficacy of a brief, guided, asynchronous internet-delivered MBCT (iMBCT) for AjD during the COVID-19 pandemic, compared with internet-delivered progressive muscle relaxation (iPMR) and a waitlist control (WLC).

METHODS

Adults meeting ICD-11 criteria for AjD (N = 301) were randomized to iMBCT, iPMR, or WLC for four weeks. Primary outcomes were changes in AjD symptoms (ADNM-20) and remission rates. Secondary outcomes were changes in depression, anxiety, cognitive fusion, experiential avoidance, and self-compassion. Outcomes were assessed at baseline, post-intervention, and one-month follow-up. Mediation analyses tested cognitive defusion and self-compassion as mechanisms.

RESULTS

iMBCT produced greater reductions in AjD symptoms than WLC (η² =.17) and higher remission rates. Compared with iPMR, iMBCT yielded larger decreases in depression and anxiety. Cognitive defusion fully mediated iMBCT effects on depression and anxiety. Some improvements were maintained at follow-up; however, findings were mixed and should be interpreted cautiously due to substantial attrition.

CONCLUSIONS

A brief, minimally guided, asynchronous iMBCT is an effective and scalable intervention for AjD that targets cognitive and self-regulatory mechanisms. Findings support the use of online mindfulness-based programs for stress-related disorders during large-scale crises.