Sunday, March 27, 2011

Childhood Trauma and Health As an adult

Paul Tough has produced a fascinating article in The New Yorker titled The Poverty Clinic. The title arises from Tough’s decision to center his story on the work of Nadine Burke who runs a clinic in an impoverished area of San Francisco. Burke is introduced as a physician who had been following traditional treatment methods for the types of illnesses encountered in the population she serves. Feeling dissatisfied with the results, she became interested in subjects like stress physiology and neuroendocrinology. Her eureka moment came when she was introduced to a study performed by Kaiser Permanente in the '90’s.

The Kaiser study was called the Adverse Child Experience study, commonly referred to as the ACE study. This effort was conducted by Vincent J. Felitti in collaboration with Robert F. Anda of the Centers for Disease Control in Atlanta. Kaiser patients in the San Diego area were provided a questionnaire that asked them to report on ten categories of “adverse childhood experiences.” Note that this involved a sample more representative of the population as a whole than that of an impoverished community. The categories included:
“....parental divorce, physical abuse, emotional neglect, and sexual abuse, as well as growing up with family members who suffered from mental illness, alcoholism, or drug problems.”
The researchers gave each participant an ACE score, with one point for each category reported. The first surprise concerned the prevalence of adverse experiences.
“Two-thirds of the patients had experienced at least one category; one in six had an ACE score of 4 or higher.”
The startling news came from comparing scores with health records.
“The correlations between adverse childhood experiences and negative adult outcomes were so powerful that they ‘stunned us,’ Anda wrote later....the higher the ACE score, the worse the outcome, on almost every measure, from addictive behavior to chronic disease. Compared to those who had no history of ACEs, those with ACE scores of 4 or higher were twice as likely to smoke, seven times as likely to be alcoholics, and six times as likely to have had sex before the age of fifteen. They were twice as likely to have been diagnosed with cancer, twice as likely to have heart disease, and four times as likely to suffer from emphysema or chronic bronchitis. Adults with an ACE score of 4 or higher were twelve times as likely to have attempted suicide than those with an ACE score of 0. And men with an ACE score of 6 or higher were forty-six times as likely to have injected drugs than men who had no history of ACEs.”
Some of these correlations involved bad behavior which could be expected to lead to poor health outcomes. Nevertheless, the researchers found that even when these bad behaviors were factored out, deterioration in health was still observed.
“The researchers looked at patients with ACE scores of 7 or higher who didn’t smoke, didn’t drink to excess, and weren’t overweight, and found that their risk of ischemic heart disease (the most common cause of death in the United States) was three hundred and sixty percent higher than it was for patients with a score of 0. Somehow the traumatic experiences of their childhoods were having a deleterious effect on their later health, through a pathway that had nothing to do with bad behavior.”

The initial response of the medical community was tepid. One could criticize the study because it depended on the recollections of the patients, and also because there was no credible explanation of the results that could be put forward. As Tough points out, research is beginning to catch up with the ACE study.

A group in New Zealand has been able to reproduce the ACE results with a group of subjects that have been under observation since the early ‘70s. That answers the first objection. Tough quotes other research activities that provide a physiological basis for the results.
“....other researchers....have made advances in explaining how early trauma creates lasting changes in the brain and the body. The key pathway is the intricately connected system that our brain deploys in reaction to stressful events. This system activates defenses on many fronts at once, some of which we recognize as we experience them: it produces emotions like fear and anxiety, as well as physical reactions, including increased blood pressure and heart rate, clammy skin, and a dry mouth. Other bodily reactions to stress are less evident: hormones are secreted, neurotransmitters are activated, and inflammatory proteins surge through the bloodstream.”

“As a response to short-term threats, the system is beneficial, even essential. But researcher like Bruce McEwen....and Frances Champagne....have shown that repeated, full-scale activation of this stress system, especially in early childhood, can lead to deep physical changes. Michael Meany....and his colleagues have found that early adversity actually alters the chemistry of DNA in the brain, through a process called methylation. Traumatic experiences can cause tiny chemical markers called methyl groups to affix themselves to genes that govern the production of stress-hormone receptors in the brain. This process disables these genes, preventing the brain from properly regulating its response to stress.”

“When it comes to adult health, the most important element of the stress response is the immune system, which, during moments of acute anxiety, releases a variety of various proteins and other chemical signals into the bloodstream. In the short term, this process promotes resistance to infection, and prepares the body to repair tissues that might be damaged. After the short-term threat disappears, this inflammation subsides, unless the system gets overloaded, in which case these chemicals can build up, with toxic effects on the heart and other organs. The [New Zealand] researchers found that adults in their thirties who had been mistreated as children were nearly twice as likely to have elevated levels of an inflammatory adults who had not been mistreated.”
This protein is a known marker for cardiovascular disease.

What this means to a physician like Burke is that
“In many cases, what looks like a social situation is actually a neurochemical situation.”
Neurochemical defects can, in principle, be treated by other chemicals. If the results of these studies are to be believed, there is a current and present need for research in this area. Burke, in surveying her own patients discovered that
“....just three percent of her patients with an ACE score of 0 display learning or behavioral problems. Among patients with an ACE score of 4 or higher, the figure is fifty-one percent.”
Tough compares these findings to those obtained in the ‘60s that showed that childhood disadvantage led to diminished educational outcomes. He suggests that society needs to think of parallel initiatives to programs like Head Start that focus on protecting children from both the mental and physical consequences of childhood trauma.

We tend to think to think of children as tough little units that nature has made resilient enough to survive almost anything life can throw at them. Perhaps survival is more complicated than we thought. And perhaps those parents who we deemed over protective of their children weren’t so far off base after all.

The more one learns about the functioning of the human body, the more important chemistry becomes. One begins to wonder if there is anything that cannot be explained in terms of a chemical state. That sounds like an interesting topic for another day.

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