In previous blog entries I shared research that showed that children and young people who were exposed to childhood trauma demonstrated biological changes within their cells (click here). This was largely a process of methylation . Methylation within a cell can switch gene actions on, off or even move a dial and is closely linked to aging. This might explain why children who suffer a high rate of of Averse Childhood Experiences have much shorter life expediencies. Previously this was assumed to be the result of maladaptive coping, such as drinking, smoking and obesity. However, even when they do not engage in these coping strategies their life is shortened. In short, this could be premature aging. This intriguing finding made me wonder whether there evolutionary pressures at the root of Averse Childhood Experiences. It would be a powerful survival strategy that when trapped in hostile environments genetic activity was accelerate to increase the pace of maturity in children. This may allow them to be more capable of dealing with threats. Could this be a mechanism that activated through childhood trauma?
A study in Biological Psychiatry has shown that exposure to violence early in life -- such as physical, emotional, or sexual abuse -- is associated with faster biological aging, including pubertal development and a cellular metric of biological aging called epigenetic age. In contrast, children exposed to forms of early life adversity involving deprivation -- such as neglect and food insecurity -- showed signs of delayed pubertal development compared with their peers.
"[The findings] demonstrate that different types of early-life adversity can have different consequences for children's development," said senior author Katie McLaughlin, PhD, who completed the study at University of Washington. Poor physical and mental health outcomes associated with early life adversity have been attributed to accelerated development. However, the new findings show that violence- and deprivation-related adversity have different effects on development, indicating that the specific type of adversity should be considered to better understand how an experience will affect a child later in life.
In children who experienced early life violence, accelerated epigenetic aging was associated with increased symptoms of depression. According to the authors, this means that faster biological aging may be one way that early life adversity "gets under the skin" to contribute to later health problems.
The 247 children and adolescents involved in the study were 8-16 years old. "These findings indicate that accelerated aging following exposure to violence early in life can already be detected in children as young as 8 years old," said Dr. McLaughlin.
"With each new study, it seems that our appreciation grows of the enormous and persisting impact of early life exposure to violence. This new knowledge calls for increased societal investment in reducing the exposure of children to violence and for biomedical and psychological research to reduce the impact of these experiences throughout the lives of these vulnerable individuals," said John Krystal, MD, Editor of Biological Psychiatry.
Although researchers don't know if accelerated epigenetic aging is permanent or if it can be reversed, the association between the aging metrics and symptoms of depression in this study may offer a way for doctors to identify children who need help. "Accelerated epigenetic age and pubertal stage could be used to identify youth who are developing faster than expected given their chronological age and who might benefit from intervention. Pubertal stage is an especially useful marker because it is easy and inexpensive to assess by healthcare providers, and could be used to identify youth who may need more intensive health services," said Dr. McLaughlin.
Materials provided by Elsevier.
Jennifer A. Sumner, Natalie L. Colich, Monica Uddin, Don Armstrong, Katie A. McLaughlin. Early Experiences of Threat, but Not Deprivation, Are Associated With Accelerated Biological Aging in Children and Adolescents. Biological Psychiatry, 2018; DOI: 10.1016/j.biopsych.2018.09.008