Schizophrenia is a disabling mental disorder which can cause hallucinations, delusions and can affect a person’s psychological, emotional and physical wellbeing. While conducting research on this mental illness, John Hopkins Medicine has disclosed that there is a possibility that early contacts with dogs at childhood may help reduce the risks of such a child developing Schizophrenia when they attain adulthood.
Lead Author Robert Yolken M.D, who is a professor of neurovirology in pediatrics at the Johns Hopkins Children’s Center, and doubles as Chair of the Stanley Division of Pediatric Neurovirology disclosed this recently while explaining that many chronic psychiatric disorders may be attributed to environmental predisposing factors that then contribute to altering the immune system. He stated that since a lot of children get exposed to dogs in early childhood, it was only logical for the medical team to determine the effects this would have on their health in the long run.
Previous studies earlier carried out have indicated that close contact with cats and dogs have a part to play in modifying the immune system of a person through allergies, home microbiome changes, exposure to animal bacteria and/or viruses, and, the effects of reduced stress levels caused by pets in the overall chemistry of the human brain, among others. Yolken, like many other investigators, suspects that these immune system modifications may help to change/ reduce the risks of developing some psychiatric disorders even in people that are already genetically predisposed to them.
This new study was carried out by a team of researchers from Sheppard Pratt Health System in Baltimore with the aim of studying and discovering the link between early pet-exposure and children 12 years and below and schizophrenia or bipolar disorder. A total of 1,371 people comprising both the male and female gender were observed, from the age range 18-65. Of the 1,371 people, 396 had schizophrenia while 381 had bipolar disorder with the remaining 594 being controls.
The result showed that the participants who had early childhood exposure to dogs had significantly reduced risks of developing schizophrenia in adulthood while also showing that there was no significant connection between dogs and bipolar disorder. Early exposure to cats seemed to have no relationship between both schizophrenic and bipolar disorder.
The researchers have warned that these findings still need to be confirmed by a series of subsequent connecting studies to discover the linking factors behind the findings and for a more accurate definition of the risks of developing psychiatric disorders from childhood exposure to household pets in children below 13 years of age.
The Schizophrenic patients, as well as the ones clinically diagnosed with bipolar disorders, were sources from the rehabilitation programs of Sheppard Pratt Health System, including the inpatient and day hospital while the controls who were screened for current or past psychological disorders were brought from the Baltimore area.
The selected participants were asked a couple of questions to discover if they were exposed to household pets like cats and dogs during their childhood when they were 12 years and below. The participants who disclosed that they had such pets when they were born were included in the group that was considered to have early childhood exposure to pets.
Results of Study
The results of the study showed that there was as much as a 24% decrease in the risk of developing schizophrenia in adulthood for people who were exposed to pets at age 13 and below. The age of exposure plays an important role in the effects of childhood exposure as in Yolken’s words, “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,”. Speaking further, Yolken also stated that “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,”
If these studies are anything to go by and can be adapted to be a reflection of the larger society, it may suggest that 24% of the entire US population living with schizophrenia may not have been victims of the disease if they had been exposed to dogs at an early age.
The case of bipolar disorder, however, records different findings from that of schizophrenia as no effect whatsoever (both good or bad) was discovered to be associated with early childhood pet exposure, but reiterating the importance of the time of exposure to the research findings, he mentioned that the researchers found a slightly reduced risk of developing both diseases for children who were first exposed to cats and dogs between the ages of 9 – 12.
The new series of research was borne out of the need to gain a better understanding of the relationship between psychiatric disorders and pet exposure so that adequate prevention, control, and treatment mechanisms can be put in place to check the diseases. This need arose after previous studies confirmed that the toxoplasmosis disease, which can trigger schizophrenia and which has pet cats as the primary hosts of its causal parasites can be transmitted from such cats to human beings through the pet’s defecation.
Researches showed that people who had been exposed to these toxoplasmosis-causing parasites had an increased risk of developing schizophrenia in the future and other psychiatric disorders. The studies also showed that a lot of people who had schizophrenia and other psychiatric ailments also had large levels of antibodies to the parasite.
These disturbing findings were what led to more research on the relationship between early exposure to cats and the futuristic development of psychiatric disorders. This new study from the Sheppard Pratt Health System in Baltimore is the first to include dogs in the investigations and is a step in the right direction towards achieving more quality and precise investigations into the relationship between household pets and psychiatric disorders.
The findings of the new study can be found published in PLOS One