Strict parenting may hard-wire the risk of depression into a child’s DNA, new research suggests. According to the study, being manipulative or harshly punishing a child can alter the way the body reads their DNA.
Experts argue that these changes can effectively become hardwired to the DNA of those children who perceive their parents as harsh, increasing their risk for depression later in life. Presenting the work at the European College of Neuropsychopharmacology Congress in Vienna, Dr Evelien Van Assche said: “We discovered that 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.
“We have some indications that these changes themselves can predispose the growing child to depression. This does not happen to the same extent if the children had a supportive upbringing.”
She added: “In this study we investigated the role of harsh parenting, but it’s likely that any significant stress will lead to such changes in DNA methylation; so, 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.”
Researchers from the University of Leuven in Belgium picked 21 children who reported good parenting, for example, the parents being supportive and giving the children autonomy. These were compared to 23 who reported harsh parenting, for example, manipulative behaviour, physical punishment, excessive strictness. All of the children were between 12 and 16 years old.
The study, which has not yet been peer-reviewed – found that many of those who had experienced harsh parenting showed initial, subclinical signs of depression.
Researchers also looked at the range of methylation – a normal process that occurs when a small chemical molecule is added to the DNA, changing the way the instructions written in DNA are read by the body. They found it was significantly increased in those who reported a harsh upbringing.
Dr Van Assche said: “We based our approach on prior research with identical twins. Two independent groups found that the twin diagnosed with major depression also had a higher range of DNA methylation for the majority of these hundreds of thousands of data points, as compared to the healthy twin.”
Now working at the University of Munster, Germany, Dr Van Assche continued: “The DNA remains the same but these additional chemical groups affect how the instructions from the DNA are read. Those who reported harsher parenting showed a tendency towards depression and we believe that this tendency has been baked into their DNA through increased variation in methylation.
“We are now seeing if we can close the loop by linking it to a later diagnosis of depression, and 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.”
