For years, therapy dogs have been employed as assistants to physically disabled individuals. More recently, the use of animal-assisted therapy (AAT) has been expanded for those with emotional and psychological conditions. Today, we'll look at the science behind therapy dogs for depression and anxiety, what exactly do they do and how these dogs can actually assist people.
There are several studies that have been conducted in the twenty-first century that have suggested that dogs can help elevate positive moods, reduce loneliness, and reduce depression. However, in a world full of dog lovers, it may be difficult to distinguish the credible research from sheer experimenter bias in favor of our four-legged friends.
So how much of it is hype versus hard evidence?
First, when discussing Animal-Assisted Therapy (AAT), it is important to understand that owning a therapy dog or a service dog for therapeutic purposes is not the same as owning any ordinary dog from a shelter or pet store. There are specific designations.
An AAT dog can be defined as follows:
“AAT is a goal-directed intervention in which an animal [in this case, a dog] that meets specific criteria is an integral part of the treatment process. AAT is directed and/or delivered by a health/human service provider working within the scope of practice of his/her profession. AAT is designed to promote improvement in human physical, social, emotional, and/or cognitive functioning. AAT is provided in a variety of settings and may be group or individual in nature. This process is documented and evaluated.”
Before debunking any of the evidence in existence that supports the idea that therapy dogs are beneficial to people suffering from depression (or anxiety), let’s take a look at the results from a few recent studies with therapy dogs.
Therapy Dogs for Depression
How effective are they according to research?
What the Research With Therapy Dogs Actually Shows
A number of studies regarding therapy dogs for depression have focused on elderly patients in hospitals and nursing facilities. Caring.com, a popular site on senior living, has a great article on all the ways that pets, and therapy dogs in particular, improve people's mental health and sometimes even save lives.
During old age, it is not uncommon for people to experience feelings of loneliness and despair. These feelings often contribute to depressive disorders and, thus, dogs are sometimes incorporated either in therapy or in daily visitation activities to improve these symptoms.
A study in 2002, and again in 2005, examined self-reported loneliness in a long-term care facility. The study concluded (1) that regular visitations with dogs lowered rates of self-reported loneliness.
On the other hand, another study conducted more than a decade prior (2) and more importantly, a study from nearly twenty years ago (3) where they examined elderly nursing home patients with depression after two years with a live-in dog versus another nursing home without a dog. Although depression was lowered among patients in the home with the dog, depression was also lowered in the home without the dog.
Moreover, researchers Alan Beck and Aaron Katcher warned about the studies related to animal-assisted therapy, where there was a clear failure in separating the “feel good” factor from actual science-based long term clinical benefits for depression.
Therefore, it is possible that therapy dogs for depression may not enhance the therapy already provided to patients dealing with depression, but more conclusive evidence is needed at this time.
Another study in 2009 (4) by Marieanna Le Roux and Rene Kemp at Stellenbosch University in South Africa produced similar results when patients with depression either spent six weeks with regular dog visitations or six weeks without dog visitation. Again, no significant difference between the two groups of patients was evident.
That same study also analyzed the self-reported anxiety of the same patients considering that anxiety and depression often go hand-in-hand. Alas, the results indicated that the presence of a dog as a means of therapy did not make any difference for either depression or anxiety conditions in a controlled environment.
In another study from 2009 (5), researchers in Germany were also interested in examining anxiety symptoms of hospitalized patients suffering from major depressive disorder and how therapy dogs for depression may help.
The researchers used the same self-report survey method of measuring anxiety as the previously mentioned study.
However, the results differed from previous conclusions, as it was found that those who received visitation by therapy dogs had significantly lower self-rated anxiety. Those who did not receive visitation by therapy dogs had unchanged rates of anxiety.
Taking into account the differing results from nearly identical studies, it is crucial to note that survey-based studies are not the most reliable due to the subjectivity of the self-reports. One person’s depression rating of “5 out of 10” might be more or less severe than another person’s rating of “5 out of 10.”
So, going back to what Beck and Katcher said more than two decades ago, we're still facing the same problems with animal-assisted therapy studies today – they're not well-structured and do not produce good enough evidence for or against using therapy dogs for depression or anxiety. Furthermore, another investigation into 14 equine therapy clinical trials (6) just confirmed this.
Hal Herzog, PhD, has written a great article on this for Psychology Today, analyzing more studies on animal-assisted therapy, and coming to the same conclusion.
Although it may be difficult to fathom the possibility that dogs may not in fact contribute to reducing depression and improving our overall mood state, the evidence does not appear strong enough yet to support the favorable outcome that they do (nor has it yet been concluded that dogs definitely do not help with depression and/or anxiety).
Another important thing to note is that too many studies concerning therapy dogs and depression specifically focus on elderly patients with depression. This cannot be generalized to the entire population of people with depression or anxiety.
Most of the current studies on therapy dogs for depression has not been done by true experiments either, in that they only suggest correlations but not causation.
Finally, because depression is difficult to measure outside of self-reports, the accuracy of results remain questionable. Therefore, we remain unsure whether therapy dogs indeed reduce anxiety and/or help people to deal with depression.
That being said, placebo effect cannot be ignored as it has been shown in numerous studies (7) to be effective and have therapeutic potential. This means that if you believe your therapy dog has helped your condition, it's a good enough reason to advocate for getting therapy dogs for patients with depression and anxiety.
The Bottom Line
Research on the benefits of therapy dogs among people with depression is currently inconclusive, and there's no hard evidence that therapy dogs actually help people to deal with depression or anxiety.
Most research showing improvements in patients with depression or anxiety have been extremely flawed in structure, and we are yet to see a good study on the subject.