What if mental disorders like anxiety, depression or post-traumatic stress disorder aren’t mental disorders at all? In a compelling new paper, biological anthropologists call on the scientific community to rethink mental illness. With a thorough review of the evidence, they show good reasons to think of depression or PTSD as responses to adversity rather than chemical imbalances. And ADHD could be a way of functioning that evolved in an ancestral environment, but doesn’t match the way we live today.
Adaptive responses to adversity
Mental disorders are routinely treated by medication under the medical model. So why are the anthropologists who wrote this study claiming that these disorders might not be medical at all? They point to a few key points. First, that medical science has never been able to prove that anxiety, depression or post-traumatic stress disorder (PTSD) are inherited conditions.
Second, the study authors note that despite widespread and increasing use of antidepressants, rates of anxiety and depression do not seem to be improving. From 1990-2010 the global prevalence of major depressive disorder and anxiety disorders held at 4.4% and 4%. At the same time, evidence has continued to show that antidepressants perform no better than placebo.
Third, worldwide rates of these disorders remain stable at 1 in 14 people. Yet “in conflict‐affected countries, an estimated one in five people suffers from depression, PTSD, anxiety disorders, and other disorders,” they write.
Taken together, the authors posit that anxiety, depression and PTSD may be adaptive responses to adversity. “Defense systems are adaptations that reliably activate in fitness‐threatening situations in order to minimize fitness loss,” they write. It’s not hard to see how that could be true for anxiety; worry helps us avoid danger. But how can that be true for depression? They argue that the “psychic pain” of depression helps us “focus attention on adverse events… so as to mitigate the current adversity and avoid future such adversities.”
If that sounds unlikely, then consider that neuroscientists have increasingly mapped these three disorders to branches of the threat detection system. Anxiety may be due to chronic activation of the fight or flight system. PTSD may occur when trauma triggers the freeze response which helps animals disconnect from pain before they die, and depression may be a chronic activation of that same freeze response.
Labels matter
Labels are something we internalize to define who we are and what we are capable of. All too often, labels limit us. And that’s why reconsidering how we label anxiety, depression or ADHD is important. Does someone have depression, a medical disorder of their brain, or are they having a depressed adaptive response to adversity? Adversity is something we can overcome, whereas a mental disorder is something to be managed. The labels imply very different possibilities.
Consider how we label ADHD. A generation ago boys with ADHD were labelled as “bad boys” and were given penalties or detentions. Now we help kids with ADHD understand that they have a “learning difference.” Instead of detention, we try to provide support in a variety of modalities. When we do, the behavior problems often disappear. That label change to learning difference is vital, because it gives space for kids with ADHD to be “good kids” and to succeed. Yet ADHD is still “attention deficit and hyperactivity disorder.”
In Finland, where substantial physical activity is part of the school day, rates of ADHD are also very low. Meanwhile, in the U.S. children are asked to sit still for the majority of the day. Elementary school students often get only 15-20 minutes of recess a day, a far cry from the 60-90 minutes their parents had. Coincidentally, ADHD rates in the U.S. have gone up over the last 15 years.
ADHD is not a disorder, the study authors argue. Rather it is an evolutionary mismatch to the modern learning environment we have constructed. Edward Hagen, professor of evolutionary anthropology at Washington State University and co-author on the study, pointed out in a press release that “there is little in our evolutionary history that accounts for children sitting at desks quietly while watching a teacher do math equations at a board.”
If ADHD is not a disorder, but a mismatch with a human environment, then suddenly it’s not a medical issue. It’s an issue for educational reform. And that is a compelling thought, given the evidence that kids’ focus and cognition are improved by physical activity. Still, we need to take this study with a grain of salt. There is a large body of research showing other biological factors when it comes to ADHD. For instance, there is evidence that premature birth increases rates of ADHD later.
Social reform or medical treatment?
Study author Kristen Syme, a recent WSU Ph.D. graduate, compares treating anxiety, depression or PTSD with antidepressants to medicating someone for a broken bone without setting the bone itself. She believes that these problems “look more like sociocultural phenomena, so the solution is not necessarily fixing a dysfunction in the person’s brain but fixing dysfunctions in the social world.”
It’s a fair criticism of the way we treat mental illness. But the stated goal of the paper is not to suddenly change treatments, but to explore new ways of studying these problems. “Research on depression, anxiety, and PTSD, should put greater emphasis on mitigating conflict and adversity and less on manipulating brain chemistry.”
But what about the fact that there is plenty of medical evidence for that brain chemistry? Consider a recent study done in Turku, Finland. Researchers showed that the symptoms associated with depression and anxiety are connected to changes in the brain’s opioid system already in healthy individuals.
Can we reconcile brain studies like this with the biological anthropologists criticism of how we handle mental health? Actually we can. The changes in the brain associated with anxiety and depression are evident, but that doesn’t mean they can’t be understood as responses to adversity.
Based on this, do we need to make changes in how we treat mental health? Yes and no. When it comes to what labels we use, a change is welcome. Mental health recovery in part, depends on whether patients believe they can get better. Telling our patients that their symptoms may be tied to a healthy response to adversity could be very encouraging.
It’s not news to doctors that mental health is impacted by adversity. In my own medical training, I was taught the biopsychosocial model, implying interconnected causes of these problems. But until social reform actually does remove social causes of suffering, physicians must continue to provide the standard of care to our patients. The history of medicine is a story of healers using the best treatments they had at the time, until better ones arrive.
