Truthiness of the Trauma-Informed Science-Policy Gap

Source: Wikimedia Commons

What Happened

On August 9, 2018, another city passed a resolution to promote a trauma-informed approach in public policy. The New Orleans city council unanimously approved a request that the Orleans Parish Children and Youth Planning Board examine issues surrounding childhood trauma and provide recommendations.

Passing resolutions to support so-called trauma-informed approaches is becoming more and more popular. The cities of Baltimore and Philadelphia, and the state of Wisconsin, just to name a few, have passed resolutions and launched publicly-funded education programs. As a researcher, my main concern about these efforts is that all of the resolutions have in common some outstandingly bad language about the alleged impact of trauma on victims’ brains. This language misrepresents the state of our scientific knowledge about trauma in order to promote the super-scary notion that proponents of toxic stress have been disseminating. Here is an excerpt from the New Orleans resolution:

“WHEREAS, researchers have found that frequent exposure to violence causes children to be in a constant state of alarm, which can result in physical changes in their brains; and

WHEREAS, these effects can be toxic to the brain, particularly in the regions responsible for memory, emotions, stress responses and complex thinking, resulting in difficulties with anger management, impulse control and the processing and retention of information; and

WHEREAS, frequent exposure to violence and other trauma can also result in physical health problems later in life, including cardiovascular disease, obesity, diabetes, and a compromised immune system; . . . “

These statements are nearly identical to the resolutions and project materials from other cities, and appear nearly identical to the publicity that spins from proponents of the Adverse Childhood Experiences Study (ACES).

Why the Resolution is Wrong

There are hundreds of studies that have established that individuals who have experienced psychological trauma and developed posttraumatic stress disorder (PTSD) show neurobiological differences compared to individuals who do not have PTSD. These include differences in the major stress responses systems, which are the autonomic nervous system (heart rate, blood pressure, and skin conductance differences) and the hypothalamic-pituitary-adrenal (HPA) axis (cortisol).

The critical question is how those neurobiological differences got there. There are two possible theories. The diathesis stress theory states the differences existed prior to the traumatic experiences and we don’t know what caused them. These neurobiological differences are probably vulnerability factors that explain why some individuals develop PTSD and others do not. The toxic stress theory, on the other hand, states that trauma caused the neurobiological differences and the brains of individuals have been permanently damaged by exposure to trauma.

The only way to know which theory is right is to examine the neurobiology of individuals before they are exposed to trauma and then examine the neurobiology a second time after they are exposed to trauma and develop PTSD. From 1986, when the first neurobiology of PTSD study was published, until 2002, the only studies that were conducted did not examine the neurobiology of individuals before they were exposed to trauma. Those early studies only examined the neurobiology of individuals AFTER they had already developed PTSD. Because of that profound weakness of study design, those early studies have absolutely no power to tell us about causation.

Examining individuals before they are exposed to trauma is extremely difficult, but not impossible. Researchers have studied soldiers before they were deployed to war zones, police recruits before they went out in the field, and individuals who were involved in studies for other reasons and then were exposed by chance to traumatic events. These are called pre-trauma prospective studies. Despite being difficult to conduct, since 2002 there have been approximately 20 of these studies, and nearly every one of them has supported the diathesis stress theory and has failed to support the toxic stress theory (My previous blog titled Have You Lost Your Mind? briefly describes one of those studies).

Why This Matters

It is not uncommon for science to be misused for political purposes. The end game for the proponents of the toxic stress theory is to influence public policy. From the first time the super-scary notion of toxic stress was mentioned in the literature in relation to psychological stress (National Scientific Council, 2005), the proponents of the belief have made it clear that this is the hammer they will use to drive the nail of spending taxpayer funds on social programs, in what they call closing the science-policy gap. They want publicly-funded support for better day care, better health screening, change of practices in juvenile justice, education in schools, education of police officers, and more.

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Whether the diathesis stress theory or the toxic stress theory is right matters for science for several reasons. First, it can influence how researchers conduct the next experiment. If a trauma researcher believes that a hippocampus becomes abnormally small after being exposed to traumas, then that researcher is never going to do a study to investigate how a hippocampus can be small for other reasons. That researcher will never conduct the right experiment. We’ve seen this played out over and over again with researchers conducting cross-sectional studies instead of pre-trauma prospective studies.

Second, which theory is right also matters because it influences how clinicians conduct psychotherapy. If clinicians believe that trauma causes damage by making brain centers shrink, therapists will be reinforcing the notion with patients that their brains are permanently damaged. Instead, therapists could be teaching patients that they may have had preexisting vulnerability factors that influenced their lives in a host of different ways.

Third, which theory is right matters because it has influenced laypersons who have no particular expertise in neuroscience to believe the stress-damages-the-brain theory. Legislators are passing resolutions and changing public policies on the unproven belief system that experiences such as violence can literally shape brains. As the state of Wisconsin resolution proclaimed, stress exposure can “shape the physical architecture of a child's developing brain and establish either a sturdy or a fragile foundation for all the learning, health, and behavior that follows.” This extraordinary belief apparently has the force to alter how taxpayers’ funds are spent and public policies are crafted.

For more information on this topic, see my past blogs titled Trauma-Informed Approaches: The Good and the Bad and The Myth of Trauma-Informed Care.