Early Exposure To Dogs May Lessen Risk of Developing Schizophrenia

[appalachiablue]

-'Early-life exposure to dogs may lessen risk of developing schizophrenia,' Findings do not link similar contact with cats to either schizophrenia or bipolar disorder. Science Daily, Dec. 18, 2019. Johns Hopkins Medicine Summary. Excerpts:

Ever since humans domesticated the dog, the faithful, obedient and protective animal has provided its owner with companionship and emotional well-being. Now, a study suggests that being around 'man's best friend' from an early age may have a health benefit as well -- lessening the chance of developing schizophrenia as an adult. And while Fido may help prevent that condition, the jury is still out on whether or not there's any link, positive or negative, between being raised with Fluffy the cat and later developing either schizophrenia or bipolar disorder.
"Serious psychiatric disorders have been associated with alterations in the immune system linked to environmental exposures in early life, and 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," says Robert Yolken, M.D...



- To be happy and healthy, live in harmony with animals, plants and nature, the way we're supposed to.

In the study, Yolken and colleagues at Sheppard Pratt Health System in Baltimore investigated the relationship between exposure to a household pet cat or dog during the first 12 years of life and a later diagnosis of schizophrenia or bipolar disorder. For schizophrenia, the researchers were surprised to see a statistically significant decrease in the risk of a person developing the disorder if exposed to a dog early in life. Across the entire age range studied, there was no significant link between dogs and bipolar disorder, or between cats and either psychiatric disorder. The researchers caution that more studies are needed to confirm these findings, to search for the factors behind any strongly supported links, and to more precisely define the actual risks of developing psychiatric disorders from exposing infants and children under age 13 to pet cats and dogs.

According to the American Pet Products Association's most recent National Pet Owners Survey, there are 94 million pet cats and 90 million pet dogs in the United States. Previous studies have identified early life exposures to pet cats and dogs as environmental factors that may alter the immune system through various means, including allergic responses, contact with zoonotic (animal) bacteria and viruses, changes in a home's microbiome, and pet-induced stress reduction effects on human brain chemistry.
Some investigators, Yolken notes, suspect that this "immune modulation" may alter the risk of developing psychiatric disorders to which a person is genetically or otherwise predisposed.

In their current study, Yolken and colleagues looked at a population of 1,371 men and women between the ages of 18 and 65 that consisted of 396 people with schizophrenia, 381 with bipolar disorder and 594 controls...All study participants were asked if they had a household pet cat or dog or both during their first 12 years of life. Those who reported that a pet cat or dog was in their house when they were born were considered to be exposed to that animal since birth..
Surprisingly, Yolken says, the findings suggests that people who are exposed to a pet dog before their 13th birthday are significantly less likely -- as much as 24% -- to be diagnosed later with schizophrenia. "The largest apparent protective effect was found for children who had a household pet dog at birth or were first exposed after birth but before age 3," he says.
Yolken adds that if it is assumed that the hazard ratio is an accurate reflection of relative risk, then some 840,000 cases of schizophrenia (24% of the 3.5 million people diagnosed with the disorder in the United States) might be prevented by pet dog exposure or other factors associated with pet dog exposure.

"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," Yolken says. For bipolar disorder, the study results suggest there is no risk association, either positive or negative, with being around dogs as an infant or young child...

More, https://www.sciencedaily.com/releases/2019/12/191218153448.htm

NYT, https://www.nytimes.com/2019/12/24/well/mind/having-a-dog-as-a-child-is-tied-to-a-lower-risk-of-schizophrenia-as-an-adult.html

[malaise]

1. That's good news for me

I'm that little girl in the photo - with my Sooty

[appalachiablue]

5. Same here, we always had doggies since we were small. All

Last edited Sat Feb 1, 2020, 12:54 AM - Edit history (1)

family loves them except one in law who has allergies and can't be around any plants or pets-- only inanimate things.

MORE, Toxoplasmosis, FT
https://www.sciencedaily.com/releases/2019/12/191218153448.htm

[Rollo]

2. Has there been any research establishing that schizophrenia is an immune disorder?

[appalachiablue]

4. It's been explored since the 1950s but this info. is a bit hard

to untangle and there's nothing solid IMO. See post #3 re 'biological basis.'

https://www.psychiatrictimes.com/schizophrenia/examining-link-between-immune-system-and-schizophrenia

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6435494/

[Mike 03]

7. This is a most fascinating question.

Not to take anything away from the astounding benefits of having a relationship with a dog. There's no doubt in my mind that one of the treasures of life is relating with animals (my family has always had dogs and cats).

I wonder about children who, like in my family, were allowed to (and did) play outside and get really dirty, etc... Now there's even a phobia about kitchen sponges, and I worry about the consequences of children who are not exposed to common microbes.

[appalachiablue]

8. Several people I know are concerned about kids, esp. only

children having decreased exposure to microbes, pathogens, pets and nature because of being raised in smaller families in urban environments.

The 'hygiene hypothesis' rose up by the late 1980s and emphasizes the importance of exposure to agents, and also the long history humans have with 'helminths' (worms) which we evolved with but which have been eradicated by public health measures in the 20th century.

https://en.wikipedia.org/wiki/Hygiene_hypothesis

https://en.wikipedia.org/wiki/Helminthic_therapy

When I brought up this topic to my 90 year old aunt, one of 10 children and the mother of four, she laughed and said, 'you mean walk through more cow patties?'

[janterry]

3. Much of the model remains biological

But clearly there are protective factors

https://www.nhs.uk/news/mental-health/schizophrenia-risk-around-80-genetic/
The researchers looked at twins born in Denmark and found that if one identical twin had schizophrenia, the other twin (with the same genes) was also affected in about a third of cases. For non-identical twins, who only share on average half of their genes, this was true only in about 7% of cases. Based on these figures, the researchers calculated that 79% of the risk of developing schizophrenia was down to their genes.

While the findings suggest genes do play an important role in schizophrenia, this is only an estimate and the true picture is likely to be more complicated. Environmental factors clearly still have an influence on whether the person actually develops schizophrenia.

[appalachiablue]

6. Thanks, I agree pretty much. There's some data

on immune issues in #4 but it's complex and not decisive. Pooches are truly 'man's best friend.'

[Rollo]

9. I'm inclined to think it's mostly psychological...

A child exposed to the devoted attention of a dog may be more trusting and less afraid of the world, and less likely to develop irrational fears later on in life. The microbiome may have nothing to do with it.

However I have read there is a positive correlation between Cesarean section births and childhood asthma. In an Cesarean birth, the infant is not exposed to the maternal microbiome. It's pretty much a sterile field, which means the immune system remains immature in a critical period.