The Role of Attentional Control in Mindfulness Intervention for Emotional Distress: A Randomized Controlled Trial With Longitudinal Mediation Analyses

ABSTRACT Objective This study aimed to investigate whether attentional control serves as a mediator for mindfulness‐based interventions for emotional distress, utilizing a randomized waitlist (WL)‐controlled design. Methods A total of 498 participants with high emotional distress was recruited online and randomly assigned to a 49‐day online Mindfulness Intervention for Emotional Distress (MIED) group ( N = 249) or a WL control group ( N = 249). Levels of attentional control, anxiety and depression were assessed at baseline (T0), Week 3 (T3), Week 5 (T5) and Week 7 (postintervention, T7). Results Linear mixed models revealed significant Group‐by‐Time interaction effects for attentional control ( p < 0.001), anxiety ( p < 0.001) and depression ( p < 0.05). Latent growth curve analyses demonstrated a significant increase in attentional control and a decrease in anxiety and depression levels during the MIED programme. These changes becoming evident starting Week 3. Longitudinal mediation analyses revealed that the slope of attentional control significantly mediated the effects of the MIED programme on the slope of anxiety and depression levels. Further, attentional control level at Week 3 significantly mediates the effect of MIED programme on anxiety and depression levels at Weeks 5 and 7. Similarly, attentional control level at Week 5 significantly mediates the MIED programme's effects on anxiety and depression levels at Week 7. Conclusions The present trial provides evidence suggesting that mindfulness interventions may alleviate emotional distress through the enhancement of attentional control. Trial Registration Chinese Clinical Trial Registry number: ChiCTR2200064140