Animal-assisted therapy on psychological and physical outcomes: a meta-analysis of randomised controlled trials

Clinical Snapshot

Key Findings

• P Value: Not explicitly reported in abstract; all three psychological outcomes described as statistically significant

• Effect Size: Depression: Hedges' g = -0.403 (moderate effect); Anxiety: Hedges' g = -0.661 (moderate-to-large effect); Stress: Hedges' g = -1.062 (large effect)

• Primary Outcome: AAT was associated with statistically significant reductions in depression, anxiety, and stress at post-intervention across diverse adult populations. No meaningful effect was demonstrated for pain or gait.

• Nnt Or Sensitivity: NNT not calculable from reported Hedges' g without baseline event rates. Using Cohen's benchmarks: depression effect (g = -0.403) is moderate; anxiety (g = -0.661) and stress (g = -1.062) effects are large, though wide CIs for the latter two substantially reduce confidence in point estimates. No sensitivity analysis results reported in abstract.

• Confidence Interval: Depression: 95% CI -0.536 to -0.271; Anxiety: 95% CI -1.069 to -0.253; Stress: 95% CI -1.849 to -0.275

Clinical Application

AAT implementation requires trained therapy animals and certified handlers, institutional infection control protocols, patient screening for allergies and zoophobia, and structured session protocols. Feasibility varies considerably across acute hospital, residential aged care, rehabilitation, and community mental health settings. Standardisation of AAT protocols remains a significant barrier to consistent implementation. AAT is not currently listed on the Australian PBS as a reimbursable intervention, nor does the TGA regulate AAT as a therapeutic device or medicine. RACGP guidelines do not currently include specific recommendations for AAT in primary care mental health management. In Australia, AAT may be accessed through some private health insurance extras cover, NDIS funding for eligible participants, or as part of allied health programs in aged care and mental health services. The findings are relevant to Australian mental health policy discussions, particularly given the high prevalence of anxiety and depression (affecting approximately 1 in 5 Australians annually per AIHW data). Clinicians considering AAT referral should note the evidence supports it as an adjunctive — not standalone — intervention, and should ensure institutional infection control and animal welfare standards are met. The Royal Australian and New Zealand College of Psychiatrists (RANZCP) and RACGP have not issued formal position statements on AAT as of the current evidence base. Adult populations experiencing anxiety, depression, or psychological stress — both clinical (e.g., hospitalised patients, those with chronic illness, mental health conditions) and non-clinical settings. Subgroup analyses suggest psychological benefits vary by population type and intervention characteristics. Results are not generalisable to pain management or gait rehabilitation based on current evidence.

Abstract

BACKGROUND: Adults are at heightened risk of anxiety, stress, and depression; animal-assisted therapy (AAT) may serve as an effective approach to promote psychological well-being. In this study, we compared the effectiveness of AAT in improving depression, anxiety, stress, pain, and gait among adults with or without illness. METHODS: We systematically searched six electronic databases (PubMed, CINAHL, Embase, Web of Science, the Cochrane Library, and Scopus) and included all studies published up to August 2024. We used comprehensive meta-analysis software to complete the quantitative synthesis. We reported pooled effect sizes as Hedges' g with corresponding 95% confidence intervals (CIs), after applying a random-effects model. Furthermore, we assessed heterogeneity using Cochran's Q test and the I2 statistic. We applied the Cochrane Risk of Bias 2.0 tool to appraise the methodological quality of the included studies. The synthesis process followed PRISMA guidelines. RESULTS: From the 13,345 studies identified, 35 randomised controlled trials involving 2391 adults were included. Across diverse populations, AAT was associated with reductions in depression (Hedges' g = -0.403; 95% CI = -0.536, -0.271), anxiety (Hedges' g = -0.661; 95% CI = -1.069, -0.253), and stress (Hedges' g = -1.062; 95% CI = -1.849, -0.275) at post-intervention, although substantial between-study variability was observed. CONCLUSIONS: We demonstrated that AAT significantly improves anxiety, depression and stress in adults, but has no meaningful effect on pain or gait. Subgroup and meta-regression analyses indicate that psychological benefits depend on population and intervention characteristics, and are not moderated by age or gender. REGISTRATION: PROSPERO: CRD42024570108.

References

1. 1.Shih, C.-Y., Arifin, H., Kustanti, C. Y., Chang, W.-J., Huang, C.-H., Fitryasari, R., Tsai, M.-C., & Ye, J.-Y. (2026). Animal-assisted therapy on psychological and physical outcomes: a meta-analysis of randomised controlled trials. Journal of Global Health. PubMed ID: 42466625. [Note: The DOI 10.1001/jamapsychiatry.2013.193 provided in source metadata corresponds to a 2013 JAMA Psychiatry publication and does not match this article. Readers should verify the correct DOI via PubMed ID 42466625 or the Journal of Global Health directly before citing.]