Tuesday, January 05, 2010

A difficult childhood = health risks?

I know from my own experience that childhood traumas can turn into psychological issues in adulthood. Now new results from a long-term study in California suggest that certain kinds of childhood traumas can translate into other kinds of health risks.

As reported in Time magazine, researchers at Kaiser Permanente have found correlations between certain kinds of traumatic events in childhood--sexual, physical, and emotional abuse--and elevated risks of heart attack, stroke, depression, emphysema, and, yes, my favorite bugaboo, obesity.

Here's a quote from the Time story:

"For the past several decades, the ACE study has recorded reports of negative childhood experiences in more than 17,000 patients. Adverse experiences include ongoing child neglect, living with one or no biological parent, having a mentally ill, incarcerated or drug-addicted parent, witnessing domestic violence, and sexual, physical or emotional abuse. . . . Compared with a person with no adverse childhood experiences, or ACEs, a person with four or more has almost double the risk of obesity. Having four or more ACEs more than doubles the risk of heart attack and stroke, and nearly quadruples the risk of emphysema. The risk for depression is more than quadrupled. Although many of these outcomes could reflect the influences of genes and other environmental influences — beyond those occurring in childhood — the tight relationship between increasing ACE numbers and increasing health risks makes the role of child trauma clear."

Some of these correlations seem straightforward, like the one between ACEs and emphysema, which can be explained at least in part by higher levels of smoking-as-self-medication. But this study takes the correlation a step further:

"Early adverse experience can disrupt the body's metabolic systems," says Dr. Jack Shonkoff, director of Harvard's Center for the Developing Child. "One of the cornerstones of biology is that our body's systems when they are young are reading the environment and establishing patterns to be maximally adaptive." Researchers also posit that high levels of stress hormones caused by ACEs can wear down the body over time. A temporary spike in blood pressure in response to a stressful event may be useful to power an adaptive fight-or-flight response, but over the long term constant high blood pressure could raise a person's risk for heart attack and stroke. Studies have also found that consistently elevated levels of stress hormones, like cortisol, can lead to permanent damage in certain brain regions linked to depression.

Even more interesting, they suggest that such stress-induced physiological changes can be passed down through the generations through epigenetics, changes in the traits expressed by genes that don't come from mutations in DNA.

Fascinating stuff. What it suggests to me is yet another refutation of Cartesian dualism. What we think and feel and experience may shape us in more ways than we know.

What do you think?