Animal-assisted therapy for schizophrenia and related disorders: A systematic review

Animal-assisted therapy (AAT) is increasingly researched as a potential treatment for physical and mental illness, including schizophrenia. The aim of the current paper is to systematically review randomised controlled trials (RCTs) to assess the effectiveness of AAT for schizophrenia and related disorders. We searched PubMed, PsycINFO, CINAHL, EMBASE, The Cochrane Library, CAB Abstracts, and Web of Science for RCTs of AAT for schizophrenia and related disorders. Primary outcomes were mental state and behaviour, clinical global response, and quality of life and wellbeing. Studies were eligible if they were RCTs that had compared AAT, or other animal-assisted intervention, to any control group using any participants with a clinical diagnosis of schizophrenia (or related disorder), regardless of age, gender, setting, or severity and duration of illness. Seven studies were identified for the review. Meta-analysis was not possible due to heterogeneity of studies, including marked differences in outcome measures and interventions. Five out of seven studies included symptoms as an outcome measure, with one reporting improvements in negative symptoms and one study reporting improvements in positive and emotional symptoms. The remaining studies reported no significant effects of AAT. Three studies included quality of life as an outcome measure but did not find any significant effects. Two studies did, however, report improvements in various measures of self-view. The use of AAT for schizophrenia remains inconclusive and there is currently not enough evidence to draw any firm conclusions due to heterogeneity of studies, risk of bias, and small samples. Rigorous, large-scale RCTs are needed to assess the true impact of AAT on schizophrenia.