Transfer effects of animal-assisted therapy on socioemotional skills in adult inpatient rehabilitation after acquired brain injury: a randomized controlled trial

Background People with acquired brain injury (ABI) often experience difficulties in social and emotional functioning, potentially affecting recovery and quality of life. Animal-assisted therapy (AAT) is increasingly used in rehabilitation to support socioemotional functioning. Objective This randomized controlled trial investigated whether the effects of AAT extend beyond therapy sessions in patients with ABI undergoing inpatient neurorehabilitation. We hypothesized that patients receiving AAT would demonstrate greater improvements in socioemotional skills compared to those receiving standard care. Methods Over 6 weeks, participants received two weekly sessions of occupational, speech, or physiotherapy with or without animals. The primary outcomes were social behavior and positive and negative emotions assessed via behavioral analyses in a standardized social situation. The secondary outcomes included depression, social cognition, therapy motivation, quality of life, and therapy adherence. The outcomes were evaluated at baseline, post-intervention, and 6- and 12-week follow-ups. Due to substantial attrition, the preregistered primary endpoint at 12-week follow-up could not be analyzed as planned. Therefore, analyses focused on post-assessment outcomes and were exploratory. Linear regression models were used to estimate mean differences. Results Seventy patients with ABI ( M  = 51.04 years, SD  = 13.39; 27.14% female) were randomly assigned to the AAT intervention group ( n  = 43) and the treatment-as-usual (TAU) control group ( n  = 27). In exploratory analyses at post-assessment, the AAT group showed higher social behavior than the TAU group ( difference  = 3.24; 95% CI [0.87, 5.62]; p  = .009). No significant group effects were found for the other outcomes. Conclusion Given the exploratory analyses following protocol deviation, these findings provide preliminary evidence that AAT may improve social behavior beyond therapy sessions in adult patients with ABI undergoing inpatient rehabilitation. Further studies are needed to evaluate the durability and real-world relevance of this effect. Clinical Trial Registration ClinicalTrials.gov , identifier NCT03687671.