Facing bullying at a young age can lead to mood problems later

bullying mood disorders

Children who face bullying by their peers at a young age are more likely to develop mood disorders at a later stage of their lives. This is because bullying changes the structure surrounding a gene which plays an important role in mood regulation. These are the results of a study carried out by researchers from Centre for Studies on Human Stress (CSHS) at the Hôpital Louis-H. Lafontaine. The study has been published in the latest issue of the journal Psychological Medicine.

The study reinforces the belief that the environment around us, including our social environment, can have a profound effect on our genes and may even lead to their mutations. According to Isabelle Ouellet-Morin, the lead author of the study, victimization experiences in the childhood not only affect the stress response but also the functioning of the genes which play a role in mood regulation.

For their study, the researchers examined 28 pairs of identical twins for the effect of bullying by their peers. The average age of the twins was around ten years. While one twin was bullied at school, the other twin was not. Identical twins living in similar environment were chosen to obliterate the changes caused by genetics or family environment. 

The researchers observed that bullied children secrete less cortisol, the stress hormone in our body. But two years before the reduction in cortisol levels occurs, there are changes in the structure surrounding the serotonin transporter gene (SERT gene) which regulates the levels of serotonin. The latter is a neuro-transmitter which plays an important part in mood regulation and depression. The bullied twins had higher SERT DNA methylation at the age of 10 years compared to their non-bullied co- twins. Moreover, the changes in the SERT gene lead to blunted cortisol responses to stress. The cumulative effect of these changes is that such children are predisposed to mood problems and other related mental health problems as they age.

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Date: 
Wednesday, December 19, 2012