Examining Differences between Homebound Older Adult Pet Owners and Non-pet Owners in Depression, Systemic Inflammation, and Executive Function

Homebound older adults are prone to depression, which is linked to systemic inflammation that promotes executive function decline. A companion animal may reduce the negative biobehavioral processes associated with depression, inflammation, and reduced executive function in homebound older adults. The primary aim of this study was to examine differences between homebound older adult pet owners and non-pet owners in depression, salivary C-reactive protein (CRP), and executive function. The secondary aim was to determine if the level of attachment to pets was associated with depression, salivary CRP, and executive function. The study was cross-sectional and investigated homebound older adult pet owners and non-pet owners (n = 88) using psychometrically reliable and valid instruments (Geriatric Depression Scale Short Form and CLOX 1). Salivary CRP was assessed with immunoassay. Level of attachment to pets was measured using a Likert scale (0-10). Mean age for the total sample was 75 years (SD = 9). Forty-eight (55%) participants owned pets (56% dogs, 25% cats, 4% other pets, 15% both cats and dogs). Pet owners reported a high level of attachment to pets (Median = 10). Pet owners had significantly higher executive function than non-pet owners (t = -2.07; p = 0.04) but there were no significant differences in executive function between cat owners and dog owners (t = 1.53; p = 0.14). Pet owners and non-pet owners were similar in depression (t = -1.80, p = 0.08) and salivary CRP levels (t = 0.27, p = 0.79). Level of attachment to pets was significantly and positively correlated with executive function (r = 0.30; p = 0.04) but was not significantly correlated with depression (r = 0.04, p = 0.77) or salivary CRP (r = -0.04, p = 0.80). Compared with non-pet owners, pet owners had better executive function but similar depression and salivary CRP levels. Reasons for these findings are unclear. Significant positive correlation between pet attachment and executive function suggests further investigation in this area. Future studies with larger samples and a longitudinal design are needed to investigate the biobehavioral changes over time in relation to pet ownership, level of attachment to pets, and executive function in homebound older adults.