The Effects of an Online Mindfulness Intervention on Perceived Stress, Depression and Anxiety in a Non-clinical Sample: A Randomised Waitlist Control Trial

Mindfulness interventions have been shown to be effective for health and wellbeing, and delivering mindfulness programmes online may increase accessibility and reduce waiting times and associated costs; however, research assessing the effectiveness of online interventions is lacking. We sought to: (1) assess the effects of an online mindfulness intervention on perceived stress, depression and anxiety; (2) assess different facets of mindfulness (i.e. acting with awareness, describing, non-judging and non-reacting) as mechanisms of change and (3) assess whether the effect of the intervention was maintained over time. The sample was comprised of 118 adults (female, n=95) drawn from the general population. Using a randomised waitlist control design, participants were randomised to either an intervention (INT) or waitlist control (WLC) group. Participants completed the online intervention, with the WLC group starting after a 6-week waitlist period. Participants completed measures of depression (PHQ-9), anxiety (GAD-7) and perceived stress (PSS-10) at baseline, post-treatment, 3- and 6-month follow-up. Participants who completed the mindfulness intervention (n=60) reported significantly lower levels of perceived stress (d=-1.25 [-1.64, -0.85]), anxiety (d=-1.09 [-1.47, -0.98]) and depression (d=-1.06 [-1.44, -0.67]), when compared with waitlist control participants (n=58), and these effects were maintained at follow-up. The effect of the intervention was primarily explained by increased levels of non-judging. This study provides support for online mindfulness interventions and furthers our understanding with regards to how mindfulness interventions exert their positive effects.