A Pilot Randomized Controlled Trial Examining the Impact of Therapy Dog Visitation on Mood, Anxiety, and Depression in Patients Hospitalized for the Treatment of Mental Illness

Background/Objectives: Evidence suggests that AAIs may be useful to support the mental health of individuals with psychiatric diagnoses, but there is limited research on the efficacy of AAIs for patients hospitalized for the treatment of acute mental illness. Methods: A randomized controlled trial (RCT) design, where patients hospitalized for the treatment of mental illness (N = 60) were randomized into to one of three conditions: dog + handler intervention (AAI), handler only conversational control (CC), or usual care (UC), for 20 min per day for three days. Mood (Smiley Face Assessment Scale), Anxiety (State Trait Anxiety Scales) and Depression (Center for Epidemiological Studies) were the outcome measures. Linear Mixed Models with random intercepts were applied to compare changes in anxiety and mood between conditions pre/post daily intervention session and pre/post three-day intervention phase (days 2–4), and anxiety and depression were assessed from baseline to the day after intervention (days 1–5) (p < 0.01). Results: Mood and anxiety improved more for the AAI than for the CC or UC conditions. Females and people who did not live with a dog experienced similar improvements in mood in the AAI and CC conditions relative to UC, while males and people who live with a dog experienced greater improvement in the AAI condition. Depression decreased similarly in the AAI and CC conditions and both were significantly better than the UC condition. Conclusions: These results indicate that a dog + handler interaction is effective for reducing anxiety and depression and improving mood in adults hospitalized for the treatment of mental illness. Human handler-only visits did not consistently result in similar findings, indicating that there may be something unique and beneficial about the presence of the dog.