Summary of findings
depression, sleep disturbance, anxiety
SECONDARY
In the largest, blinded breathwork RCT completed to date, we compared the effects on stress, mental health, sleep and wellbeing of a coherent breathing intervention (~ 5.5 bcpm) and a well-designed placebo (matched guidance at 12 bcpm), for ~ 10 min/day over four weeks, in a general population sample. This current study did not support the main hypothesis that CB would be more effective at reducing subjective stress (primary outcome) than the placebo at post-intervention (primary timepoint). In addition to stress at the 4-week follow-up, our secondary hypotheses that CB would lead to greater improvement than the placebo on measures of subjective anxiety, depression, wellbeing and sleep disturbance, were also not supported. The most parsimonious explanation is that our results suggest CB, as it was delivered here, was simply not more effective than the breathwork placebo at reducing stress and improving mental health and wellbeing. Both breathwork groups showed significant improvement on all the mental health and wellbeing outcomes over time (except sleep disturbance—no changes). However, most importantly, there were no differences between arms on the magnitude of these improvements.