There’s a certain type of person out there who, whenever they hear some expert come out against beating up children or point out that children’s wellbeing is important to their future development, will reply like this:
“Nonsense! The only time I ever saw my parents was when they came to smack me in the face with a two-by-four, I lived in a cupboard until I was 16, and my father ran over my pet bunny just to teach me a lesson about table manners, and it never did me any harm!”
However, a growing body of evidence suggests that these people are in the wrong. New research, presented at the European College of Neuropsychopharmacology (ECNP) Congress in Vienna, has found that “strict” parenting can actually alter the way children's bodies read their DNA, which could increase their biological risk for depression both in adolescence and in later life.
“Perceived harsh parenting, with physical punishment and psychological manipulation, can introduce an additional set of instructions on how a gene is read to become hard-wired into DNA,” psychiatrist Evelien Van Assche, now at the University of Munster, explained at the conference.
“We have some indications that these changes themselves can predispose the growing child to depression,” she said. “This does not happen to the same extent if the children have had a supportive upbringing.”
We know: “Too Strict Parenting Alters Children’s DNA To Make Them Depressed” sounds like a headline made up solely to garner clicks – but it’s not as farfetched as it sounds. It’s a result of epigenetics – that is, the weird science of how your environment and behavior can influence how your genes work.
So, to be clear, what we’re not talking about here is some kind of DNA mutation that results from getting spanked. “The DNA remains the same,” Van Assche explained, “but… additional chemical groups affect how the instructions from the DNA are read.”
The team confirmed this by comparing two groups of kids, all aged between 12 and 16 years old, who reported growing up under either good parenting – for example, parents who were supportive and gave them autonomy – or harsh parenting, which included things like physical punishment, manipulative behavior, and extreme strictness.
Even before DNA analysis was carried out, the team noticed that several of the children in the second group were already showing initial signs of depression. That would not be unexpected: there’s plenty of evidence that so-called “physical discipline” is associated with poorer mental health, developmental delays, reduced grey matter in the brain, and even an increased risk of drug and alcohol misuse.
But it was when the researchers took a look at the participants’ DNA that the effects of harsher parenting became not just visible, but measurable. At more than 450,000 places across the subjects’ genomes, the team found significantly increased levels of methylation – the process that occurs when a small chemical is added to the DNA, blocking certain proteins that allow the DNA to “read” the genes normally.
Increased variation in methylation is known to be associated with depression, with the BDNF and SLC6A4 genes chief among the culprits. In both cases, methylation can be a result of stress – and the researchers behind the new study think their results may be applicable in more cases than just uber-strict parenting.
“We investigated the role of harsh parenting, but it’s likely that any significant stress will lead to such changes in DNA methylation,” Van Assche said. “In general, stresses in childhood may lead to a general tendency to depression in later life by altering the way your DNA is read.”
“However, these results need to be confirmed in a larger sample,” she cautioned.
Nevertheless, the result has some big implications: “This is extremely important work to understand… how adverse experiences during childhood have life-long consequences for both mental health and physical health,” said Christiaan Vinkers, a professor in the Department of Psychiatry at Amsterdam University Medical Centre, who was not involved in the study. “There is a lot to gain if we can understand who is at risk, but also why there are differing effects of strict parenting.”
And even better: the research may even someday help those already recovering from a childhood under overly strict parents. “We are now seeing if we can close the loop by linking it to a later diagnosis of depression,” Van Assche said.
“[We could] perhaps use this increased methylation variation as a marker, to give advance warning of who might be at greater risk of developing depression as a result of their upbringing”.
The research was presented at the 35th ECNP Congress in Vienna.