Friends at school can affect our long-term health, scientists say
According to a new study, the genes of our friends at school can affect our own health in the long run.
Our friends carry genes that may or may not predispose them to mental health problems, from addiction to anxiety and depression. Researchers at Rutgers University in New Jersey say it can affect the mental health of people among their friends.
“Peer genetic predisposition to psychiatric and substance use disorders is associated with an individual’s risk of developing the same disorders in young adulthood,” said the study’s lead author Jessica Salvatore.
“What our data show is the breadth of sociogenetic influences,” he said in a university press release. Salvatore is an associate professor at the University’s Department of Psychiatry.
This is a relatively new field of study called sociogenomics: how an individual’s genetic make-up (“genotype”) can affect a wider network of people.
How strong is the sociogenomic influence? To find out, Salvatore’s team looked at data on more than 1.5 million people born in Sweden between 1980 and 1998.
They then tracked down where they went to school during their teenage years. This was followed by an in-depth review of a variety of records (medical, pharmaceutical, and criminal) documenting a history of any substance use or mental health disorder during adulthood.
They then used computational models to assess whether the genetic predispositions of a person’s peers were associated with aspects of a person’s own mental health.
Conclusion: A clear link was found between a close friend’s genetic predisposition and a person’s likelihood of developing a substance use or psychiatric disorder, the team said. The closer two people are, the greater the connection.
The researchers were even able to identify the most critical years for this effect to occur, and found that it was between the ages of 16 and 19.
The study found that the genetic influence for drug and alcohol use disorders was particularly strong for peers who attended the same school.