A new study has found that strict parenting could alter children’s DNA causing an increased risk of depression in adults.
New research presented at the European College of Neuropsychopharmacology has found a link between strict parenting and changes in the way the body reads the DNA of children, leading to an increased risk of depression in later life.
Presenting the work at the ECNP 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 have had a supportive upbringing”.
Harsh parenting and risk of depression
The University of Leuven researchers selected 21 adolescents who reported good parenting (for example, parents being supportive), and compared it with 23 adolescents who reported harsh parenting as manipulative behaviour and excessive strictness to understand if the risk of depression increases. The adolescents were aged between 12 and 16 years old, with the mean age of 14 or both groups. In both groups, 11 adolescents were boys, which means the results of the two groups were comparable, with a similar age and a similar boy-girl distribution. Many of those who experienced strict parenting showed initial, subclinical signs of depression.
Analysing DNA changes
The researchers measured methylation in more than 450,000 places in the DNA of each subject and discovered it significantly increased in those who reported a harsh upbringing.
Methylation is a normal process that occurs when a small chemical molecule is added to the DNA. This process changes the way that instructions written in DNA are read. As an example, methylation can increase or decrease depending on the enzyme produced by child hechild gene. Furthermore, increased variation in methylation can increase the risk of depression.
Evelien 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”.
Dr Van Assche (now working at the University of Munster, Germany) 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 warning of who might be at greater risk of developing depression as a result of their upbringing”.
“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”.