Mindfulness-based interventions reduce psychological distress in cancer patients and survivors, according to a systematic review and meta-analysis of randomized controlled trials. Since 2012, the number of published trials has more than doubled, allowing for a more robust analysis. The review examined the efficacy of these interventions on psychological distress as the primary outcome, along with other health outcomes. The findings support the use of mindfulness-based approaches in psycho-oncology to improve mental health among individuals affected by cancer.
Acceptance and mindfulness-based therapies appear to work partly by increasing mindful attention, decentering, and acceptance, which in turn reduce anxiety and depression. A meta-analysis of 33 randomized controlled trials (30 independent trials) found that these three processes together had a small-to-medium mediating effect on treatment outcomes. However, the type of mediation analysis mattered: studies using correlation-based methods found significant mediating effects, while those using causal time-lag analyses did not. The specific role of each mediator could not be determined. Limitations in the number and design of available studies prevent firm conclusions about whether these processes are unique or causal.