Dogs really do make the world a better place. Our furry friends are well-known for their unconditional love and loyalty, but that’s not where it ends.
At this stage, scientists are still unsure whether there’s a similar link between cats and humans.
How researchers came to this conclusion
Lead author of the research paper, Robert Yolken, chair of the Stanley Division of Developmental Neurovirology and professor of neurovirology in paediatrics at the Johns Hopkins School of Medicine, along with researchers from Sheppard Pratt Health System in Baltimore investigated the relationship between exposure to a household cat or dog during the first 12 years of life and a later diagnosis of schizophrenia or bipolar disorder.
The sample group included a population of 1 371 men and women between the ages of 18 and 65. The group was divided into three categories: 396 people with schizophrenia, 381 with bipolar disorder, and 594 with neither.
Statistics were documented about each person, including age, gender, race/ethnicity, place of birth, and highest level of parental education (as a measure of socioeconomic status). All participants were asked if they had a household pet dog or cat, or both, during their first 12 years of life.
Researchers found a statistically significant decrease in the risk of a person developing schizophrenia if exposed to a dog early in life. However, when they looked across the entire age range for a link between people who had a pet dog and developing bipolar disorder, they found no significant link. The study was published online in PLOS One.
Yolken said that some researchers suspect that this "immune modulation" may alter the risk of developing psychiatric disorders – to which a person is genetically or otherwise predisposed.
"Serious psychiatric disorders have been associated with alterations in the immune system linked to environmental exposures in early life.
“Since household pets are often among the first things with which children have close contact, it was logical for us to explore the possibilities of a connection between the two."
Yolken also commented: "There are several plausible explanations for this possible 'protective' effect from contact with dogs – perhaps something in the canine microbiome that gets passed to humans and bolsters the immune system against or subdues a genetic predisposition to schizophrenia."
Previous studies have found that having a household pet can be a good way to build the immune system in that it can ultimately change the home’s microbiome and one’s reactions to allergies, for example. This means that unpleasant dust and dander that you constantly have to deal with can actually be good for your health, especially if you have kids crawling around the house.
More research needed
While the findings may make leave dog lovers feeling thrilled, the researchers caution that more studies that search for factors that back up strongly supported links are needed to confirm their findings.
"A better understanding of the mechanisms underlying the associations between pet exposure and psychiatric disorders would allow us to develop appropriate prevention and treatment strategies," Yolken said.