Jiaxin Lv, Zhong Li, Rixin Qin, Beibei Miao, Ling Gong, Changping Song, Yali Sun, Wei Liu, Li Chen
Twenty studies, including 16 randomized controlled trials and 4 quasi-experimental studies, were included in the systematic review and meta-analysis. The pooled results showed that AAIs have a moderate and statistically significant effect on improving depressive symptoms (SMD, -0.45; 95% CI, -0.68 to -0.22; Z = 3.90; P < .001) and cognitive function (SMD, 0.72; 95% CI, 0.12-1.31; Z = 2.36; P = .018) in older adults, compared with the control group. Larger effects on depressive symptoms were observed in interventions involving live animals, quasi-experimental study designs, and intervention durations of 6 to 12 weeks. In contrast, no significant pooled effects were identified for anxiety symptoms or loneliness. The certainty of evidence was rated as low for depressive symptoms, very low for anxiety symptoms, low to very low for loneliness, and low to very low for cognitive function.
OBJECTIVES: To assess the effectiveness of animal-assisted interventions (AAIs) in improving depressive symptoms, anxiety symptoms, loneliness, and cognitive function in older adults.
DESIGN: A systematic review and meta-analysis.
METHODS: Six databases were searched from inception to January 4, 2026. Randomized controlled trials and quasi-experimental studies were included. Pooled intervention effects were calculated using standardized mean differences (SMDs). Sensitivity analyses, publication bias, subgroup analyses, and methodological quality (Risk of Bias 2 and Joanna Briggs Institute) were assessed. The certainty of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation approach.
RESULTS: Twenty studies, including 16 randomized controlled trials and 4 quasi-experimental studies, were included in the systematic review and meta-analysis. The pooled results showed that AAIs have a moderate and statistically significant effect on improving depressive symptoms (SMD, -0.45; 95% CI, -0.68 to -0.22; Z = 3.90; P < .001) and cognitive function (SMD, 0.72; 95% CI, 0.12-1.31; Z = 2.36; P = .018) in older adults, compared with the control group. Larger effects on depressive symptoms were observed in interventions involving live animals, quasi-experimental study designs, and intervention durations of 6 to 12 weeks. In contrast, no significant pooled effects were identified for anxiety symptoms or loneliness. The certainty of evidence was rated as low for depressive symptoms, very low for anxiety symptoms, low to very low for loneliness, and low to very low for cognitive function.
CONCLUSIONS AND IMPLICATIONS: AAIs are associated with significant improvements in depressive symptoms and cognitive function in older adults. No significant pooled effects were found for anxiety or loneliness. These findings support AAIs as a promising complementary approach for depression and cognitive support in later life, while underscoring the need for larger, well-designed multicenter trials to strengthen the evidence base.