Animal-assisted therapy in patients with psychotic disorders: A systematic review and meta-analysis

To synthesize the available evidence on the effects of animal-assisted therapy on core symptom dimensions (including positive, negative, and general symptoms), specific symptom domains (including depression, anhedonia, anxiety, stress) and cognitive functioning in patients with psychotic spectrum disorders.

A systematic review and meta-analysis were conducted in accordance with the PRISMA and Cochrane Handbook for Systematic Reviews of Interventions guidelines. The PubMed, Cochrane Library, Web of Science and PsycINFO databases were searched from inception to June 2025 with no language restrictions. Experimental follow-up studies implementing animal-assisted therapy in patients with psychotic disorders were included. Pooled standardized mean differences (SMDs) with 95 % confidence intervals (CIs) were estimated using a random effects model. Heterogeneity was assessed with the I² statistic.

A total of 12 studies (10 randomized controlled trials, a quasi-experimental controlled trial and a pre-post study) involving 408 patients (mean age range: 37.0-55.3 years; 32.6 % women) were included. Compared with control conditions, patients receiving animal-assisted therapy (predominantly dog-assisted) showed significantly greater pre-post improvements in negative symptoms (SMD = -0.51, 95 % CI: -0.95, -0.07; I² = 45.2 %; n = 6). No significant effects were found for positive symptoms (SMD = -0.68, 95 % CI: -1.68, 0.32; I² = 83.8 %; n = 6) or general symptoms (SMD = -0.08, 95 % CI: -0.86, 0.69; I² = 72.5 %; n = 4). Sensitivity analyses restricted to dog-assisted interventions yielded similar effect estimates. Anxiety symptoms showed reductions but could not be synthesized quantitatively.

Animal-assisted therapy may help alleviate symptoms in patients with psychotic disorders, particularly by reducing negative symptoms. Further randomized controlled trials are needed to confirm these findings and clarify their clinical significance.