The effects of loving-kindness interventions on positive and negative mental health outcomes: A systematic review and meta-analysis

Loving-kindness meditations involve sending feelings of kindness and care to a series of people including oneself, loved ones, strangers, and all beings. Loving-kindness interventions (LKIs), which include knowledge and/or practice related to loving-kindness, have been gaining attention as a potential intervention for improving mental health in adults. This meta-analysis synthesized the effects of LKIs on both positive (i.e., mindfulness, compassion, positive affect) and negative (i.e., negative affect, psychological symptoms) indices of mental health across comparison types (i.e., passive control, active control, alternative treatment) and general sample types (i.e., community, university), and explored characteristics of LKIs that may impact their effectiveness (i.e., intervention format, intervention length, presence/absence of a live facilitator). Following a systematic review of six databases in November 2023, 23 randomized controlled studies met eligibility criteria and were included in the review. Relative to passive control groups, LKIs had positive effects on mindfulness, compassion, positive affect, negative affect, and psychological symptoms; these effects were non-significant relative to active control groups and alternative therapeutic treatments. Notably, the effects of LKIs did not differ as a function of sample type, intervention format, intervention length, or the presence/absence of a live facilitator. Findings provide support for the effectiveness of LKIs relative to passive control conditions, as well as their potential comparability to alternative evidence-based therapeutic treatments, and provide insight into resource-effective approaches to the delivery of effective LKIs. However, additional studies are needed to confirm the impacts of LKIs relative to other interventions in the field.