Software designers work hard to avoid infinite loops, a problem that often requires rebooting. The ruminations and obsessions that plague many patients with paranoia or obsessive-compulsive disorder seem similar. Information can also feed back into the same loop, filling memory and shutting down the system. This is like the escalation of manic or depressive episodes to extremes that then get stuck. It is also reminiscent of the human tendency to what psychologists call “confirmation bias,” which makes us attend preferentially to all information that confirms a prior belief and ignore information that does not fit. Asking a patient with schizophrenia to describe concerns about spying by the secret police can result in some patients concluding that your questions prove that you are part of the conspiracy.
In his profound book Cybernetics, Norbert Wiener, the father of information theory, suggested that dysregulated feedback control systems might be responsible for some mental disorders. His idea is especially germane to bipolar disorder.109 Most people who experience life reverses slow down and invest less effort, but bipolar patients sometimes do the opposite. After a setback, most of us gradually recover our optimism and carry on, but patients who are vulnerable to mood disorders can slide into feedback spirals that trap them in isolation and depression.
Conversely, after a grand success most of us tend to find ourselves unaccountably feeling down a few days later. Psychologists note that this “opponent process” is a general characteristic of human motivation systems.110 One evolution-minded author has even suggested that extreme happiness itself provokes extreme depression as a stabilizing measure.111 Some system like this that helps to stabilize mood may be absent in people with bipolar disorder.
An evolutionary perspective on dire mental diseases encourages new perspectives that shift attention away from the easy assumption that because they are influenced by genes, they are caused by defective genes. It calls new attention to traits, fitness landscapes, and control systems that may result in vulnerability. What such traits might be is a very good question. They are unlikely to be things as obvious as creativity or intelligence. Instead, they may be things such as rates of neuron growth in early development, rates of neuron pruning in adolescence, and rates of transmission in neural networks. On a higher level, attributing meaning to tiny gestures by others may be increasingly useful up to some peak beyond which it crashes into sustained paranoia. I am all too aware that these are mere speculations and that the actual systems are likely to be complex in ways that make them hard to grasp. Nonetheless, investigating how selection shapes traits that maximize fitness but leave some individuals vulnerable offers opportunities to look for causes that are not underneath the streetlamps of population genetics and neuroscience.
EPILOGUE
EVOLUTIONARY PSYCHIATRY: A BRIDGE, NOT AN ISLAND
If at first the idea is not absurd, then there is no hope for it.
—Albert Einstein
Ideas won’t keep. Something must be done about them.
—Alfred North Whitehead
Why did natural selection leave us so vulnerable to so many mental disorders? The question is a good one, and attempts to answer it will deepen our understanding of mental disorders. That is the simple thesis of this book. Its aim is to encourage taking the question seriously and searching for answers. That requires constructing a bridge across the canyon that separates evolutionary biology from psychiatry, a project that is just getting started.
In the middle of the nineteenth century, tourists packed the shores of Niagara Falls. It was obvious that a bridge connecting Canada and the United States would be popular and profitable. Other engineers said it would be impossible, but Charles Ellet, Jr., took on the challenge. The first task was to get a cable across. Boats, rockets, and cannons were ruled out in favor of the kite contest Ellet announced in January 1848. A fifteen-year-old American boy, Homan Walsh, crossed to the Canadian side and flew his kite named “Union” all day and into the night, when the string went slack, severed by sharp rocks on the far shore. It was eight days until the ferry could get through the ice so he could retrieve and repair his kite and cross the border to try again. Finally, on one of the last days in, his kite spanned the gap. The thin string pulled across a stronger string that pulled a rope that pulled a cable that made possible the first bridge across the Niagara gorge.1
The canyon between evolutionary biology and psychiatry is also deep, wide, and filled with rough waters. Many strings have been severed by sharp rocks at the edges. This book floats another string across the gap in hopes that it will join existing strings to encourage pulling across successively stronger ropes and cables. Evolutionary biology is the foundational science for medicine and all studies of behavior. Bringing it to bear on mental disorders offers a new perspective that will lead to new advances.
The explanations suggested here for our vulnerability to mental disorders illustrate the opportunity; they don’t provide definitive answers. Each one requires full investigation by many scientists. I have tried to show how some are inconsistent with theory and others are contradicted by facts, but the remaining ones are not necessarily true; they are just those that best fit what we know now. Every hypothesis about evolution and mental disorders needs testing.
That is often difficult. Unfortunately, it seems easy. Human minds carve experience into categories defined by functions. Chairs are for sitting. Hammers are for pounding. Eyes are for seeing. So it seems natural to ask what schizophrenia is for and how anorexia nervosa is useful. But disorders don’t have functions. VDAA (Viewing Diseases As Adaptations) is the most serious error in evolutionary psychiatry. The error of thinking that most everything is an adaptation comes naturally to human minds. My favorite outlandish hypothesis is the suggestion that flamingos are pink so they will be camouflaged when viewed against a sunset. Physiologists and behavioral ecologists are more circumspect, but because their everyday work is about adaptations, they tend to start with the assumption that most traits are there because they offer benefits—along with inevitable trade-offs.
Other scientists are skeptical, even hostile, to suggestions about how traits are useful. Geneticists and paleontologists see the effects of random factors in their everyday work, so some tend to assume that most genes and traits are products of random events, sometimes dismissing viable hypotheses as just-so stories without even considering the evidence or alternatives. A remarkable number think that proximate or phylogenetic explanations are sufficient.
The battle between these tribes has created a scientific brouhaha.2,3,4,5,6,7 Those on one side are likely to wrongly accuse evolutionary psychiatry of “adaptationism,” despite my efforts to emphasize that nothing about the body can be perfect and plenty of problems are plain old diseases with no redeeming features. On the other side, some evolutionary psychologists will view my perspective as too slow to acknowledge adaptive functions. Battles between these groups resemble tribal warfare, with stereotyping, prejudice, and global attacks on unfortunate display. However, generalized arguments are counterproductive. Progress will come from testing specific hypotheses. Many deserve to be put on the table. Most will be knocked off by the onslaught of facts. That will take time and resources. Best strategies for testing hypotheses about disease vulnerability are still developing, but experiments, naturalistic observations, and the comparative method all can help. No simple cookbook approach will suffice.8
These challenges should not slow efforts to use our understanding of normal behavior to understand abnormal behavior. Eating disorders were not shaped by selection, but mechanisms that regulate eating during famines were. ADHD was not shaped by selection, but mechanisms that regulate attention were. Serious depression was not shaped by natural selection, but capacities for normal low and high mood were. The rest of medicine uses its understanding of normal functioning as the foundation for understanding pathology. This allows it to distinguish symptoms from diseases and to recognize syndromes such as heart failure that can
have many causes. An evolutionary framework provides psychiatry with a foundation like the one physiology and biochemistry provides for the rest of medicine.
What Good Is Evolutionary Psychiatry?
Patients want help now. Practitioners want more effective treatments. If someone you love is hospitalized with a manic episode, your only concern is that the doctors have made an accurate diagnosis and are providing the most effective treatment possible. Speculation about why we are all vulnerable to mania seems frivolous. If your spouse is headed for death from alcoholism, if your child has schizophrenia, if you have depression or obsessive-compulsive disorder that is not responding to treatment, then ideas about why evolution left us vulnerable can’t help but seem irrelevant. In the face of such urgent clinical needs, it is understandable that some people will ask, “If evolutionary psychiatry doesn’t provide better treatment, why bother?”
There are two reasons. In the long term, an evolutionary perspective will transform our understanding of mental disorders in ways that lead to better treatments. In the short term, evolutionary perspectives can be somewhat helpful even now.
An evolutionary foundation will advance research and resolve some enduring controversies. If I met Ms. A again today and she again asked if I realized that psychiatry was deeply confused, I would tell her that much confusion can be resolved. There are good reasons for bad feelings. Anxiety and depression are often excessive because they benefit genes at our expense, because of the Smoke Detector Principle, because we live in modern environments, and because regulation mechanisms are intrinsically vulnerable. Looking for problems in the brain is worthwhile, but because it is an information-processing mechanism, specific causes and brain abnormalities may be found for only some disorders. Others will turn out to be syndromes similar to kidney failure or heart failure that can have many causes. Some causes come from below, via genes and brain mechanisms; others come from above, via information and information processing. Top-down and bottom-up causes interact to create tangled webs, but this is not confusion, it is just reality. An evolutionary framework helps make sense of mental illness.
Several changes will be needed to reap the benefits of an evolutionary perspective. All health professionals and researchers should learn the basic principles of evolutionary biology. Mental health professionals should also learn how natural selection shapes brains and behavior. This cannot happen fast, because few health education professionals know enough evolutionary biology to teach it or even enough to insist that it be included in curricula. Creating new education resources and curricular guidelines will speed progress. While education is essential, funding priorities also need reform. The search for specific genetic and brain abnormalities responsible for specific diseases has gotten nearly all research funding. Some would say that this paradigm has come to a dead end. I hope that is wrong, but there is no need to put all bets on the same horse. The moment of discovery may be, as Jonas Salk suggested, the moment when we find a new question. Funding to answer new questions will open up new directions for psychiatry. Finding out how life situations influence emotions is crucial. Studies of how normal low mood is regulated and useful are needed, along with investigations of how drugs disrupt mood mechanisms in ways that relieve symptoms. Studies of persistence need to be revisited in light of the adaptive value of stopping useless effort. Foraging patterns of people vulnerable to drug abuse will be fascinating. Integration of cybernetic approaches with evolution, psychology, and neuroscience offers great promise. Dozens of studies are ready to go as soon as sponsors recognize the opportunity.
Improving treatment is the goal, but much will be lost if evolutionary psychiatry becomes just another brand of therapy. Different treatments tend to become isolated islands of shared beliefs. Such beliefs influence what people do. Or, more often, what they don’t do. Early in my career I saw many patients with severe anxiety or depression who refused medications, saying something like “Drugs will just cover over the symptoms, I need to find the cause.” The prevailing psychodynamic schema prevented them from accepting available help from medications. As the years passed and more drug ads appeared on television, the prevailing schema flipped. I provided a consultation for a desperately depressed twenty-two-year-old man whose symptoms had not responded to five different medications. He was living in the basement of his parents’ house, mostly staring at a wall, but sometimes watching television or playing video games. When I asked what he wanted to do in life, he said, “I have to get over my depression before I can do anything.” When I asked how he would do that, he said, “It is a brain disease, so I just have to wait until they find a medication that works.”
Schemas about mental disorders also limit the perspectives of clinicians and researchers. Some doctors who attribute problems to brain disorders feel little need to get a detailed history; they are satisfied with making a diagnosis and administering a treatment approved for the disorder. Conversely, clinicians who attribute problems to mental conflicts provoked by early experiences put enormous effort into dredging up memories and connecting them to current behaviors, sometimes to the detriment of considering brain problems and current life situations. Evolutionary psychiatry builds bridges between such diverse views. It gives substance and structure to George Engel’s biopsychosocial model. Instead of blaming a person’s problems on one or another specific cause, it encourages consideration of how multiple factors interact to cause this individual’s problem, and how various treatments can help to resolve it.
In the Clinic Now
My friend and colleague Alfonso Troisi, the psychiatrist at the University of Rome who coauthored Darwinian Psychiatry, has convinced me that learning about evolution can make clinicians more effective now.9,10 Those who study evolution can better understand motivations and emotions that arise in response to difficulties pursuing goals. Their understanding of relationships helps them to understand why conflicts are inevitable and how to reduce them. Martin Brüne, a German evolutionary psychiatrist and author of Evolutionary Psychiatry, has also advocated bringing evolutionary views to the clinic.11 The UK psychiatrists Riadh Abed and Paul St. John-Smith have organized hundreds of their peers in the Royal College of Psychiatry who share these interests. Clinical psychologists including Paul Gilbert and Leif Kennair are using evolutionary thinking to make cognitive behavioral therapies more effective.12,13,14,15 Clinician-researchers like these will inspire the next generation.
Despite my reluctance to claim quick benefits now, learning about evolution and behavior has transformed my treatment of many conditions. Treatment of panic disorder is improved if clinicians recognize that panic attacks are false alarms in the fight-or-flight system and that the Smoke Detector Principle explains why false alarms are common. Treatment of eating disorders is improved by the recognition that strenuous dieting arouses famine protection mechanisms that are prone to initiate a positive feedback spiral. Addiction treatment is improved by recognizing that addiction results when learning mechanisms encounter substances and routes of delivery that our ancestors never imagined. And the psychiatry residents I have trained tell me they find it invaluable to ask their depressed patients, “Is there something very important that you are trying to do that you can’t succeed at and can’t give up?”
Understanding social selection provides a foundation for understanding committed relationships and the prevalence of guilt and social anxiety. Recognizing the tension between relationships based on exchange and those based on commitment facilitates discussion with patients about what a therapeutic relationship can and cannot offer. Realizing that long hours of intimate conversation automatically create feelings of intimate connection can help keep therapeutic relationships professional.
These insights from the frontier of evolutionary psychiatry are useful now, but they should not be viewed as “evolutionary psychotherapy.” Bridges will accomplish much more than constructing a new island.
Why Is Life So Full of Suffering?
We come full circle to the largest question. For those of us who have been fortunate, life began the way it did for Siddhartha, the boy who became the Buddha. While not as perfectly cosseted as he was, we spend our early years in secure cocoons, protected by loving parents from even knowing about suffering in the larger world. When he was finally allowed to go into the city, Siddhartha confronted life’s pain and sadness with a searing abruptness that fueled his search for the cause and a solution. He concluded that suffering has its origins in desire. That seems right. If Siddhartha lived today, he would likely ask why natural selection shaped desires and the painful and pleasurable emotions aroused by their pursuit.
The general answer is simple: our brains were shaped to maximize transmission of our genes. Emotions are specialized modes of operation that are useful in certain situations. But a subtler perspective provides an escape from cynicism and determinism. We are capable of genuine goodness and caring. They make life worthwhile at the price of guilt and grief. We have built-in mechanisms for controlling desire. They are not always reliable, but they allow most of us to carry on with good humor and good relationships, little concerned about what we don’t have. All this comes at the price of caring inordinately about what others think about us. Together, these products of natural selection make life happy and meaningful for many, even most, people. All of this encourages turning one more question on its head. Instead of being appalled at life’s suffering, we should be astounded and awed by the miracle of mental health for so many.
Good Reasons for Bad Feelings Page 31
