A Systematic Review of Animal-Assisted Therapy on Psychosocial Outcomes in People with Intellectual Disability

• This systematic review examined the literature of animal-assisted therapy on psychosocial outcomes in people with intellectual disability.
• Positive results were reported in four areas of psychosocial outcomes: behaviour, cognitive, emotional and social.
• The quality assessment of the included studies found the majority of studies were weak in design.

The aim of the study was to review the literature on animal assisted therapy (AAT) in people with intellectual disabilities (ID) measuring psychosocial outcomes (behavioural, social, cognitive and emotional). Quantitative studies were found through a systematic search that identified studies using AAT in people with ID and measuring psychosocial outcomes (behavioural, cognitive, emotional and social). The quality of studies was assessed using a standardised tool and rated as strong, moderate or weak. Only published articles from peer-reviewed journals were included. No language or age restrictions were applied. Over half of the included studies were identified outside standard database searches (e.g. hand searching reference lists from included articles, references from AAT websites and using Google Scholar and a Grey Literature Database). Ten studies were included in the final review; two were rated as moderate quality and eight were rated as weak quality. Overall there was a positive improvement reported from studies for all psychosocial outcomes (with some cognitive, behavioural, social, emotional components reaching statistical significance p ≤ 0.01). Despite having no age restrictions, the included studies had participants that were mainly children and adolescents, in particular favouring male participants, which may limit generalisation. More rigorous methodology is required to improve the quality of future studies including in the main multicentre randomised designs and improved reporting according to CONSORT criteria. Further research should expand to include adults with ID and specific disorders such as challenging behaviour or mental illness.