A recent finding from a study,lead by Isabell-Ouellet-Morin of the University of Montreal, shows that childhood bullying can cause physical changes to a victims DNA. The study which was part of the Environmental Risk Longitudinal Twin Study resulted in showing that trauma from bullying can effect a bullied child's mental health into adulthood. According to findings published in the journal of Psychological Medicine, there are mutations in a particular mood regulating gene when bullying occurs. If that mutation does occur there is strong possibility that the mutation may prevent a person from adequately handling stressful situations as an adult.
The research showed that bullied subjects who consisted of identical twins with an average of 10, had changes in the structure of a serotonin regulating gene. We are all familiar with link of serotonin, and depression. Many drugs prescribed for depression increase the production of serotonin for those who are depressed because of a lack of it. Serotonin is a neurotransmitter that directly related to mood regulation and depression.
So in essence it would absolutely seem conceivable that bullying as a child effects one's lie in adulthood. Not just in bad memories and self esteem but depression. I would think that if this is true then I would say bullying is not the only childhood trauma that changes this regulating gene. Child Molestation, Rape, Sexual Battery, Child Abuse and the list goes on. In my opinion, Bullying is a form of a child abuse where a child[ren] is [are] the perpetrator[s] and many times the abuse is ignored.
Reference: ABC News and the Inquisitir.com