Pet-therapy: a trial for institutionalized frail elderly patients. Twenty-eight subjects with chronic age-related disabilities living in the nursing home were assigned to a pet-therapy intervention group, consisting of 3/week sessions of almost one-hour visit for 6 weeks with a little cat, of to a control group undergoing usual activity programs. Pet-therapy has shown a significant reduction not only in depressive symptoms but in blood pressure as well. (Stasi, Amati et al. 2004).
AIDS diagnosis and depression in the Multi-center AIDS Cohort Study: the ameliorating impact of pet ownership. This beneficial effect of pet ownership occurred principally among persons who reported fewer confidants. These results suggest that by enhancing companionship for some HIV-infected persons, pets may buffer the stressful impact of AIDS. (Siegel, Angulo et al. 1999; Cline 2010; Vollestad, Sivertsen et al. 2011).
Hearing dogs: a longitudinal study of social and psychological effects on deaf and hard-of-hearing recipients provided assistance dogs that alert their deaf or hard-of-hearing recipients to key sounds, thus increasing their independence and also providing companionship.
There were a number of significant differences in measures of well-being between the period prior to placing the Hearing Dog and the period after placement. Recipients reported significant reductions in hearing-related problems such as response to environmental sounds; significant reductions in measures of tension, anxiety, and depression; and significant improvements in social involvement and independence.
The longitudinal nature of this study supports evidence that these improvements persist for some time after the placement of a dog, with significant differences being reported, in many cases, up to 18 months after acquiring a dog (Guest, Collis et al. 2006).
Guest, C. M., G. M. Collis, et al. (2006). “Hearing dogs: a longitudinal study of social and psychological effects on deaf and hard-of-hearing recipients.” Journal of deaf studies and deaf education 11(2): 252-261.