Owning or exposure to a dog in early life can lower the risk of a person developing schizophrenia as an adult according to a study.
Findings show decline in a statistically significant decrease in the risk of a person developing the disorder if exposed to a dog early in life. The study entitled “Exposure to household pet cats and dogs in childhood and risk of subsequent diagnosis of schizophrenia or bipolar disorder” looked at the link 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.
Published on PLOS ONE, the study 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," says Robert Yolken, M.D., lead author of the study and chair of the Stanley Division of Pediatric Neurovirology and professor of neurovirology in pediatrics at the Johns Hopkins Children's Center.
Researchers examined 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. Their age, gender, race/ethnicity, place of birth and highest level of parental education (as a measure of socioeconomic status) were taken into consideration.
The study observed patients with schizophrenia and bipolar disorder from inpatient, day hospital and rehabilitation programs of Sheppard Pratt Health System. Control group members from the Baltimore area underwent a screening to exclude any record of psychiatric disorders.
"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.
Yolken and colleagues at Sheppard Pratt Health System in Baltimore emphasize that their findings need to be confirmed by further studies. The objectives of these future studies should examine the factors behind any strongly supported links and to exactly define the actual risks of developing psychiatric disorders from allowing infants and children under age 13 to be exposed to and interact with cats and dogs.
"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," Yolken says.
