What is the saddest truth about pets

The Sad Truth About Pet Owning And Depression

What a Review of 30 Studies on the Impact of Pets on Depression Reveals

According to the UK newspaper The Independent, "a growing body of studies" shows that pets can alleviate a range of mental health problems, including depression.

The Independent is far from the only one to announce that a pet is driving the blues away. But media reports extolling pets' effectiveness in treating depression are usually based on only a few studies. So, to get a broader picture of research on pet ownership and depression, I took a closer look at the research literature on the subject. I expected that most studies would find that owning a pet was associated with lower rates of depression. Finally, in response to a recent post on pets and suicide, several readers wrote to me that their relationship with their dogs had even prevented them from killing themselves.

But that's not how the results turned out.

There's a lot of research going on about pets and depression

Using Google Scholar, I found 30 articles in peer-reviewed journals that looked at the rate of depression in pet owners and non-owners. Fifteen of the studies were conducted in the United States, with most of the others in Europe. Much of the research on pets and depression has focused on the elderly. Half of the studies looked at older pet owners and non-pet owners, 12 studies looked at adults of a broad age range, and 3 studies focused on adolescents.

What I found was surprising.

Most research shows that pet owners are no less depressed

  • Eighteen of the 30 studies found that as a group, there were no differences in the incidence of depression between pet owners and non-pet owners.
  • Five studies reported that pet owners were more likely to be depressed than non-owners.
  • A couple of studies got mixed results.
  • One study reported that unmarried women with pets were less depressed than unmarried men who did not own pets.
  • And a 1999 study found no overall differences in depression rates between gay and bisexual men, but found that HIV-positive men with pets who had few or no friends were less depressed.
  • Only 5 of the 30 studies found that pet owners as a group suffered less from depression than people who did not live with a pet.

The problem of sample size

When all other things are equal, researchers tend to be more confident in studies with more subjects than studies with fewer subjects. A total of 117,233 participants were included in the 30 studies I examined, with the number of participants ranging from 88 to 53,418. The five studies that found pet owners to be less depressed had, on average, far fewer participants (mean = 401 subjects) than the studies that found no difference in depression rates (mean = 4,683 subjects) or that found pet owners to be more depressed (Mean = 4,975 subjects). Eleven studies had more than 1,000 subjects, but none of these large studies reported that pet owners as a group were less likely to experience depression.

What about older pet owners?

Fifteen of the studies focused on older adults, but only one reported that seniors with pets were better off with depression. Nine of the studies found no differences in depression levels between pet and non-pet owners. And four of them found that pet owners were more likely to be depressed.

Can Owning a Pet Reduce Depression in Some People?

There may be exceptions for some groups. Here are a few areas that might be worth pursuing.

  • Depression in adolescents. Two studies reported that homeless children with pets had significantly lower rates of depression (here and here). In another study, children with positive attitudes towards pets had lower levels of depression and crime rates.
  • Social loss. A 2019 study reports that older pet owners who suffered loss from spouse death or divorce were less depressed than non-pet owners who suffered a loss.
  • Gender differences. It is possible that pets' effects on depression can vary based on the gender of the owner. For example, a 2006 study found that unmarried women with pets were less depressed than non-owners, but unmarried male pet owners had more depressive symptoms.
  • Attachment to a pet. You'd think that people who have a close bond with their pets are less likely to experience depression. However, the results are mixed. A 1989 study found that owners who were more attached to their pet were more likely to be depressed, but the relationship was weak. However, this study reported that in people living alone, stronger attachment to a pet was associated with more depression.
  • Types of pet owners. It is entirely possible, and indeed likely, that some types of pet owners are more likely (or less) to experience depression than other types of pet owners. For example, Florida State University researchers recently reported that women older than 85 years old who only live with one cat are more likely to be depressed than other categories of older adult pet owners.

Why Should Pet Owners Be More Depressed?

For unclear reasons, pet owners were more depressed than non-owners in five studies. One possibility, of course, is chance. However, I think this is unlikely; three of these studies had more than 1,000 subjects. As is often the case with claims about the “pet effect” on human well-being, we do not know the direction of the causal arrow. It is certainly possible for depressed people to get a pet in the hope that their animal companion will alleviate their loneliness and depression. Researchers have also found that many pet owners become depressed from the death or illness of a loved one.

The bottom line

After spending maybe 20 hours tracking down articles in obscure journals, studying tables of depression scale values, and emailing researchers for copies of their manuscripts, I came to several conclusions.

  • First, most research does not support the claim that owning a pet is associated with lower rates of depression.
  • Second, there are some exceptions. This includes studies of homeless children and street children, women and people with AIDS who live alone, and people who have lost a partner. More research is needed in these areas.
  • Finally, according to a pet industry advertising campaign, "pets are increasingly being included in depression treatment programs." The reality, however, is that most scientific studies have found that a puppy, no matter how cute, is usually not an effective substitute for Zoloft or Prozac.

While loneliness has been linked to "18% of cases of depression in older adults" there are many reasons to get a pet, but depression treatment is not one of them.