It is debatable whether loving-kindness and compassion meditation (LKCM) effectively reduces anxiety, and previous studies have reported inconsistent findings. This study provides a systematic review and meta-analysis of the effects of LKCM on anxiety. Studies that took LKCM as the main body and measured anxiety as an outcome were included. There were no exclusion criteria for sample characteristics or control groups. Among 327 empirical studies published up to March 2022 on LKCM, 59 measured anxiety as an outcome. Meta-analyses showed that LKCM interventions are effective in reducing anxiety (d = -0.28, k = 19, n = 1284 for randomized controlled trials; d = -0.48, k = 26, n = 1177 for nonrandomized trials; d = -0.58, k = 6, n = 503 for laboratory experiments). The heterogeneity was high between studies. Subgroup analyses for randomized controlled trials found that studies combining loving-kindness meditation and mindfulness meditation outperformed studies adopting loving-kindness meditation alone. Moreover, studies with waitlist controls had greater effect sizes than studies with active controls. The type of anxiety, participant characteristics, protocol, or length of intervention had no statistically significant moderating effects. Individual studies supported mindfulness and self-compassion as important mechanisms, but the amount of meditation practice made a limited contribution. LKCM interventions can be effective in reducing anxiety. The incremental value of combining mindfulness meditation with loving-kindness meditation is encouraging. More research is needed, especially on specific populations suffering from anxiety disorders. PROSPERO CRD42021245515

Loving-kindness and compassion meditation (LKCM) was a promising intervention for improving life satisfaction, but previous findings have been inconsistent. The current study provides a systematic review and meta-analysis, including 23 empirical studies on LKCM with life satisfaction as an outcome variable. The primary meta-analysis indicated that LKCM significantly enhanced life satisfaction in pre-post design (g = 0.312, k = 15, n = 451), but the significance disappeared in the additional meta-analysis based on randomized controlled trials (g = 0.106, k = 6, n = 404). Moderator analyses found significant effects for type of control (i.e., the effects of LKCM were inferior to active control group, but superior to waitlist condition), but not for other moderators (i.e., participant type, previous meditation experience, specific protocol, components of LKCM, combination with mindfulness mediation, and intervention length). Narrative review identified self-compassion and positive emotions as important mediators. The practice time of LKCM had indirect but not direct association with life satisfaction. The findings supported that LKCM is promising in increasing life satisfaction, but more studies are needed to investigate the effects with more rigorous designs. Future studies should investigate other potential mechanisms and clarify whether LKCM change the reality or the perception of life.