Impact Of Adverse Events In Early Life

A recent study at the Massachusetts General Hospital (MGH) has found evidence that children under the age of 3 years are usually the most vulnerable to the effects of adverse life experiences such as poverty, family and financial instability, and abuse. Such experiences may have consequences on their epigenetic profiles, chemical tags that alter gene expression and future mental health. The report finds that the timing of adverse experiences has much more powerful effects as compared to the number of such experiences or whether they took place recently or long back. Studies have time and again reflected that the first three years of life are an important period for shaping biological processes that finally give rise to mental health conditions.

Not just in humans, similar patterns are also found in animals. Adverse experiences in early life have deep impact on their lives. The present study was designed in order to test the hypothesis that there are sensitive periods during which adversity is related to greater changes in DNA methylation. The investigators then drew a comparison of the model to an accumulation hypothesis, in which the effects of adversity increase with an increase in the number of events, and a recent hypothesis, that the effects of adversity are largely strong when events happened more recently. In order to complete the study, data was collected from participants in the U.K.-based study titled Avon Longitudinal Study of Parents and Children. The participating parents reported regularly on many aspects of the health and life experiences of their children, who were enrolled in the study even before their birth. The present investigation observed and critically analyzed the data from a subgroup of more than 1,000 randomly selected mother/child pairs from which DNA methylation profiles had been run for the children at birth and at age 7. The study found that the children's encounter with adversity before the age of 7 years was based on the fact that whether parents reported their child's repeated experience of seven stressors:

• abuse by a parent or other caregiver,

• abuse by anyone,

• a mother's mental illness,

• living in a single-adult household,

• family instability,

• family financial stress,

• neighborhood disadvantage or poverty.

The investigators further recorded the number of exposures to each adversity, and the fact that whether or not they were experienced at specific developmental stages and how close they occurred to the age at which blood samples were taken for the second methylation profile. The study concluded that exposure to adversity was usually associated with increased methylation. Methylation is a phenomenon that reduced the expression of specific genes; and neighborhood disadvantage appeared to have the greatest impact, followed by family financial stress, sexual or physical abuse, and single-adult households.

By: Anuja Arora

Content: https://www.sciencedaily.com/releases/2019/05/190501131347.htm