Non-randomized controlled trial examining the effects of livestock on motivation and anxiety in patients with chronic psychiatric disorders

Objectives: Patients with chronic schizophrenia exhibit negative symptoms, including decreased work motivation. Animal-assisted therapy programs have been reported to benefit such patients; hence, there is a possibility that sheep-rearing, rather than conventional employment training, may motivate these patients. Therefore, we investigated the effects of a one-day experiential learning program of sheep-rearing on the work motivation and anxiety of patients with chronic schizophrenia.

Methods: Fourteen patients were included in a non-randomized controlled trial conducted between August 2018 and October 2018. The patients' participation in the sheep-rearing experiential learning (one day; intervention day) and normal day care (one day; control day) programs were compared. The salivary cortisol and testosterone levels and State-Trait Anxiety Inventory (STAI) scores of the patients were analyzed.

Results: The patients' salivary testosterone was significantly higher on the intervention day (p = 0.04) than on the control day (p = 0.02). Their salivary cortisol was lower on the control day than on the intervention day, although the difference was not significant. Regression analysis was performed based on the change in salivary cortisol levels and STAI-Trait scores (p = 0.006), and a regression equation was established.

Conclusions: The study revealed that participation in sheep-rearing may have promoted the testosterone production but did not increase anxiety in patients with schizophrenia. Additionally, regression equations for salivary cortisol levels in such patients may provide information on individual differences in anxiety levels.