Does Stress Damage the Brain?
Understanding Trauma-Related Disorders from a Mind-Body Perspective

J. Douglas Bremner

Overview – Excerpt – Table of Contents

We carry our stress with us for a lifetime. Our bodies have biological systems that respond to life-threatening danger, acting like fear alarm systems that are critical for survival. When faced with a threatening situation, such as being attacked by a tiger, a flood of hormones and chemical messengers is released into our brains and blood stream almost instantly. These hormones rapidly shift our energy resources away from non-critical tasks, and toward more critical tasks that are required for survival. Energy is shunted to the brain and the muscles to help us think fast and run quick, and away from the stomach and digestive track as well as the reproductive system, since we are not now under a time pressure to eat lunch or reproduce. This stress-responsive activation of biological systems helps us to shift our priorities in energy utilization and use of resources, and to focus the body in a variety of ways on doing whatever it takes to survive. If we later encounter a similar threatening situation, specific fear-related areas in the brain turn on more quickly and activate the fear areas with greater efficiency. That is because the stress hormones more strongly engrave the circumstances surrounding the life-threatening event in memory, by acting on brain areas that are involved in memory.

The short-term survival response can be at the expense of long-term function. For instance, release of stress hormones can cause thinning of the bones, ulcers, and damage to a part of the brain involved in memory with associated problems with memory. Surprisingly, the same biological systems that help us survive life threats can also damage the brain and body.

A central thesis of this book is the development of the idea that stress-induced brain damage underlies and is responsible for the development of a spectrum of trauma-related psychiatric disorders, making these psychiatric disorders in effect the result of neurological damage. Another primary thesis of this book is that there is no true separation between what happens in the brain and what goes on elsewhere in the body. Our old distinctions between mind and brain, psychology and biology, mental and physical, increasingly appear to have no meaning as science deepens or understanding of how the mind and body function in health and disease. This leads us to the final thought that stressors, acting through a depression or disruption of mental processes, can translate directly into an increased risk for poor health outcomes, including heart disease, cancer, and infectious disease, in addition to the increased risk for psychiatric disorders.

Brain areas responsible for memory play an important role in the stress response. It makes sense that a good memory and quick thinking would be important for survival. If a large and scary animal jumps out at you when you are strolling through the jungle, you need to know whether that is your playful but loyal dog Spot who has returned from a run through the jungle, or whether it is that man-eating tiger that almost had you for lunch last summer. If you react like your life is going to come to an end every time that Spot jumps out of the bushes, you won't have a very happy time in the great outdoors. Ironically you also may not be as likely to survive. If everytime you hear "Boo" you have an all out fear reaction, you may not be able to respond as efficiently as you should when a real threat jumps in front of you. Like Peter who cried "Wolf" too often, your body's defense systems may become depleted by repeated responses to non-threatening events, so that when a truly threatening event comes along, they are not able to respond in the way that they should. In a similar way, traumatized individuals who have excessive fear reactions for even the most trivial events, are ironically in greater danger than most people, because when they encounter a truly dangerous situation, they are already depleted and not able to mount as good of a defense as they otherwise would have been able to do.

This is why having a good memory can really help you out in a jam. It shouldn't be surprising therefore that the same parts of our brains that play role in memory and quick thinking also play an important role in the stress response. Hormones such as cortisol and adrenaline that are released during stress bathe these brain areas and change their function, bringing them back to a similar state as during prior dangers, when there was also a stress-induced outpouring of stress hormones cortisol and adrenaline. These hormones help us check our notes for the current event against past dangers, and think quickly about what is the right thing to do, whether it is run away or stay and fight. The stress response mobilizes brain systems and brain areas that mediate memory and responses to stress that are critical for survival. However with excessive or repetitive stress some individuals can develop long-term changes in these same brain systems that mediate memory and the stress response. Like a car engine that burns out on the excessive speeds of the Autobahn (the German freeway where there are no speed limits), our bodies can become irreversibly damaged by our own stress responses. Our stress response systems are fine-tuned to adapt to changes in our environment, however like a thermometer that is exposed to a really hot summer, after a while it can no longer respond to excessive increases in the heat, and doesn't turn the temperature down. In the same way an individual exposed to repeated stress develops dysfunction in their stress response system, and can no longer properly adapt to new stressors. Stress responses that are useful for short-term survival can be at the expense of long-term function.

The stress hormones cortisol and adrenaline mediate many of the negative long-term consequences of stress on the body. Although cortisol released during the time of the life-threatening danger is one of the most important factors that help us to survive, it may have long-term negative effects on several organ systems. The parts of the body that are most sensitive to the "wear and tear" effects of stress over time are (logically enough) those areas that are mobilized during the stress response¹. Many of these effects are mediated by increased release of the body's hormonal systems, including cortisol, that act like fire alarms to mobilize the resources of the body in life threatening situations. The hormones cortisol and adrenaline travel throughout the body and brain and have a number of actions that a critical for the survival during life threatening danger. Adrenaline has a number of actions in the body, including stimulation of the heart to beat more rapidly and squeeze harder with each contraction, while norepinephrine acting in the brain helps to sharpen focus and stimulate memory. Blood pressure increases to increase blood flow and delivery of oxygen and glucose, necessary energy stores for the cells of the body to cope with the increased demand. There is a shunting of blood flow away from the gut (digestion of the pasta salad you had for lunch can wait for a while) and toward the brain and the muscles of the arms and legs (you need to think fast and/or run hard to get away from the threat). The spleen increases the release of red blood cells, which allows the body to send more oxygen to the muscles. The liver converts glycogen to glucose, the type of sugar that can be immediately used. Breathing becomes heavy, so that extra oxygen can get to the lungs, and the pupils dilate for better vision. Release of endogenous opiates acts on the brain to dull our sense of pain, so that the pain of a physical injury incurred during an attack does not impair our ability to escape from the situation. More delayed stress responses include release of cortisol, which dampens the immune system (we are less likely to die immediately from an infection than from our attacker), and conversion of fat to glucose in the liver.

[insert diagram showing the effects of stress on different organ systems]

These stress hormones can have more insidious detrimental long-term effects. For instance, excessive levels of cortisol result in a thinning of the lining of the stomach, which increases the risk for gastric ulcers. Cortisol also results in a thinning of the bones, which increases the risk of osteoporosis or bone fractures in older people, or an impairment in reproduction (which can play havoc with the desire of stressed out young professionals to start a family). Other diseases that have been linked to stress include heart disease, diabetes, and asthma. Stress also impairs the immune system, which can lead to an increase in infections and possibly even increased rates of cancer. Chronic stress with decreased blood flow to the intestines can result in chronic ulcers.

Public wisdom emphasizes the relationship between stress and heart disease, however there has been surprisingly little research actually conducted in this area. The studies that have been conducted do support such a connection, and in fact suggest that stress-related hormonal release may represent the mechanism of increased risk for heart disease. Cortisol released during stress acts to increase blood pressure, heart rate, and cholesterol, and raises blood levels of adrenaline (norepinephrine and epinephrine)^2,3. All of these factors can lead to an acceleration of atherosclerosis. Studies in animals in fact have found direct evidence for the damaging effects of stress on blood vessels in the heart. Studies in monkeys undergoing chronic social stress, related to changes in their hierarchies of which monkey is dominant at any one particular time, found a relationship between stress and accelerated cardiovascular disease. Monkeys undergoing stressors had increased activation of cortisol and norepinephrine systems, which led to the accelerated development of arteriosclerosis. Stressed monkeys had increased injury to the inner lining of the blood vessels in the heart, which led to increase clumping of platelets and the forming of blood clots, increasing the risk for heart attack⁸. These studies showed that there is in fact a direct link between stress and the development of heart disease, and in fact the bodies hormonal response to stress is involved in the mechanism for the development of heart disease.

Stress-related release of cortisol and other metabolic and endocrine stress-related changes may also increase susceptibility to stroke^2,4. For instance, prisoners of war from WWII were found to be seven times more likely to have had a stroke at some time in their lives than non-POWS.7 fold

Stress interacts with other aspects of behavior to increase the risk for poor physical health. For instance women who were sexually abused in childhood, even those without any psychiatric disorders, were found to be twice as likely to smoke as non-abused women. Having the diagnosis of PTSD increased the risk for smoking even more. Experiments showed that exposure to reminders of their trauma increased the craving for cigarettes, as well as PTSD symptoms, in patients with PTSD. Administration of nicotine reduced both craving and anxiety and PTSD symptoms. Cigarettes actually act on the brain to release a neurotransmitter called dopamine, that has a beneficial effect on reward centers in the brain. Thus both stress and PTSD can increase the risk of heart disease and cancer, acting through an increase in risky behaviors like cigarette smoking.

Psychiatric disorders related to stress, including both PTSD and depression, may confer their own additional risk for poor physical health. Patients with both depression (which is related to stress in many cases) and heart disease are about five times as likely to die suddenly in the aftermath of a heart attack than patients with heart disease without depression^5,6. Stress has been closely linked with the onset of depression, and it is not known whether stress has a direct effect on cardiovascular disease in patients who also develop depression, or whether the effects are mediated directly through the depressive disorder. For example, there are several findings in depression, which may influence cardiovascular function. Patients with depression have increased levels of cortisol and adrenaline. As mentioned above, increased levels of cortisol and adrenaline/norepinephrine can affect cardiovascular function in several ways, including increasing heart rate and blood pressure, damaging the inner surface or causing constriction of the blood vessels in the heart, or affecting the function of platelets that are involved in forming blood clots. Both stress and depression may also decrease the variability of the rhythm of the heart, which is known to be associated with an increased risk for sudden death.

Posttraumatic stress disorder (PTSD) has also been associated with an increased risk for several physical disorders. PTSD patients are at increased risk for heart disease, above and beyond the risk associated with exposure to stress. New evidence suggests that PTSD, above and beyond the influence of stress per se, may increase the risk of several other physical disorders, including diabetes, ulcers, asthma, and possibly cancer. As mentioned above, PTSD is associated with an increased risk for smoking, which may lead to increased risk for heart disease and cancer. Treating PTSD may therefore improve more than just the misery associated with living with this disorder. It may also lead to an improvement in physical health symptoms.

The effects of stress on physical health appear to be caused by a disruption of the balance between different organs of the body, or homeostasis. According to this model, stress results in long term 'wear and tear' which leads to poor health and an increased risk for mortality.

A number of research studies are also consistent with the idea that stress can also have detrimental effects on brain structure and function. Stress has detrimental effects on memory and cognition that can lead to long-term dysfunction. This is at least partially mediated through the effects of stress on a brain area involved in learning and memory called the hippocampus. Elevated levels of the stress hormone cortisol during stress can lead to damage to this brain area. Stress therefore is often associated deficits in memory, specifically the ability to learn new information. Chronically elevated levels of cortisol may also affect mood, leading to depression and feelings of fatigue.

It may seem paradoxical that the stress response systems responsible for the survival of the individual may actually have damaging effects. This paradox makes more sense when considered in the light of evolution. Surviving long enough to pass on your genes is the only concern from the standpoint of human evolution. Once you have performed this task, and have survived long enough for your offspring to become self sufficient, from the standpoint of evolution it doesn't matter whether or not you live to a ripe old age. Therefore more chronic and non-acute ailments, such as memory problems or gastric ulcers, are not as important as whether you released enough adrenaline and cortisol to escape the acute life-threatening situation. In prehistoric times most people didn't live very long beyond the time it took to reproduce and raise their offspring, so it didn't really matter anyway. It is only now that we are faced with the prospect of vast legions of the elderly who have sacrificed their minds to a stressful life on Wall Street, and now are spending their well-earned retirement years wandering around a Walgreen's Pharmacy in South Florida, trying to remember which medication they need to buy for their gastric ulcers.

Behind the idea that stress can causes changes in physical health, and also result in neurological changes that underlie psychiatric disorders, is a seemingly radical idea. The idea that what you see, hear, smell, and feel, what comes in through the eyes, ears, and nose, can cause lasting changes in physical health, is something that crosses conventional thinking. This conventional thinking is based on the false dichotomy between mind and brain/body that dates back to the French philosopher of the 18^th Century, Rene Descartes. However scientific discoveries of the past few decades are not consistent with the false dichotomy of Descartes. What we are learning is that events in the environment, including stressful experiences, education, and family events, can affect our physiology, even acting to modify our genetic material.

The current false dichotomy between psychology and biology has not always existed. In fact the word psychology derives from the Greek word psyche, which was the Greek word for the soul or the spirit, and which literally meant butterfly. For the Greeks, the psyche was an actual physical entity, although invisible, and would inhabit the body until the time of death, when it would travel to the Underworld of Hades. The Greeks had other words for physical parts of the body which also had carried emotional meaning. For instance, the Greek word thumos represented a part of the body that was thought to be somewhere in the region of what we now know is the stomach. Thumos represented several qualities including strength of will and character. Another organ called phrenos was located roughly in the area of the liver, which is the source of our word, diaphragm. This word refers to psychological qualities and can be translated as mind or spirit. In fact a number of psychological, spiritual or emotional qualities were ascribed to physical organs whose function today we would assign to the brain. The Greeks did not separate mind or spirit from body. They were eminently practical people and it would not have occurred to them that any part of what is the human being would not have a physical substance or substrate. Even their gods they considered in a very concrete and physical way, living their lives in a sort of super-human way on top of Mount Olympus. It was with the development of Christianity that we developed the idea of pure spirit or mind as being separate from any aspect of our physical body. This culminated with the absurd practices of fasting, self-flagellating the body, or retreating to live in isolation on top of a pillar, all practices of Christianity that were designed to punish or diminish the body in order to amplify the spirit, practices performed by early Christians which were considered to be insane by the ancient "pagan" Greeks. The dualistic way of thinking engendered by Christianity underlines our current false dichotomy between mind and brain, psychology and biology that led to it's absurd climax in the philosophical thinking of Descartes, who search for a source of the soul somewhere in the brain, and ultimately decided that it lay in the pineal gland.

The false dichotomy between mind and brain led to the basis for the 20^th Century view of psychology which was dominated by the thinking of Sigmund Freud. Under the influence of Freud and psychoanalysis, psychology was completely divorced from medicine and the physical sciences. This led to the absurd situation where in my father's generation, young doctors spent ten years studying medicine and basic sciences, only to be sent on to "unlearn" the scientific principles and way of evaluating information in their subsequent psychiatric education and "training psychoanalyses". However the knowledge that strong emotions or things that happen to you can affect your physical health has continued to be preserved in folk wisdom, like some long lost harbinger from the ancients, in the popular knowledge that extreme emotions can influence function of the heart, the stomach and other physical organs. Over the past two decades there has been an explosion of research and scientific knowledge that has established that what you experience and what you think and feel can have profound effects on you body's physiology and on your brain. This has lead us to the point where we are now ready to reintegrate mind and brain, body and spirit.

This new way of thinking about the effects of stress on the individual has important implications for mental health. Mental disorders were previously felt to have no basis in the body or the brain. Gradually scientists came to realize that many mental disorders may have their basis in stress-induced alterations in brain function and structure. Even more recently we started to realize that not only the brain but also other organ systems may mediate so-called mental disorders. We may be moving back to the old Greek concepts of thumos and phrenos, examining the effects of stress on a range of "physical" and "mental" outcomes, including heart function, digestion, metabolism, immunity, and brain function. The concepts of thumos and phrenos, may be particularly applicable for those mental disorders that have long been recognized as being associated with stress exposure, like PTSD, anxiety and depression, as opposed to other metals orders like schizophrenia, which have not been associated specifically with stress and which of long felt to be have their basis in the brain, genetics and abnormal brain development. This new way of thinking about the effects of stress and other environmental factors on the individual will also be beneficial for everyone in our society, not just for those who are diagnosed with mental disorders. In an increasingly stressful society, it will be useful to think about the effects of stress on the entire individual, both in the brain, the heart, and other physical systems. This reversal of the false dichotomy of mind and brain established by the philosophy of Descartes will have beneficial effects for promoting health and happiness in everyone.

A central theme of this book is the stress can have lasting effects on the individual, leading to changes in function of the brain as well as other physical systems. An important point to be made in the ensuing chapters is that these changes in the brain underlie many of the symptoms of mental disorders related to stress, including PTSD and depression, as well as other disorders that probably have at least in part their basis in exposure to stress, including alcohol and substance abuse, eating disorders, borderline personality disorders, Somatization disorders, and anxiety disorders.

There has been a rapid change in thinking about the effects of stress on the individual in recent years. This can be seen in the explosion in the number of reports of childhood abuse in the media and in our legal system. Could it be that we have a new epidemic of childhood abuse? Or has there been a change in people's attitudes about whether or not to keep these terrible secrets within the family or to bring them out into public view. Likewise there has been an incredible expansion in our direct exposure to traumatic stressors on a daily basis. You only have to turn on the television to see a shooting at a public school taking place in front of our very eyes in real time, or to see round the clock coverage of a hostage standoff. The rapid expansion of technology has made it possible for us to see all the terrible things that are happening everywhere in the world at any time anywhere we are. This has been both a blessing and a curse. Our constant exposure to traumatic events has created the feeling that we are in an increasingly unsafe world. This goes against our natural need to feel safe, to work and take care of our families, and to not become distracted by the possibility that a traumatic event could intrude into our lives at any moment.

Nevertheless in our society we are exposed to surprisingly high rates of traumatic stress in our daily lives. For instance, epidemiologic studies have shown that 25 to 50% percent of Americans are exposed to a psychological trauma at some time in their lives¹. And the magnitude of psychological trauma in our society is much greater than most people think. There are about one million veterans of the Vietnam War who experienced the stress of combat between 1963-1971, which included seeing others killed or wounded, and being exposed to artillery or gunfire. Several hundred thousand veterans of the Gulf War experienced the stress of being in the Gulf War theater in 1990-1991. These soldiers were exposed to the constant stress of SUD missile attacks, air raid alarms, participating in the assault on Kuwait which involved bulldozing Iraqi soldiers into their trenches, or passing hundreds of charred bodies who had been torched by the preceding Air strikes before the land assault. Add to this the stress of exposure to burning oil wells and the possibility (or reality) of chemical attack, and this was not a happy time for many veterans. Equal numbers of veterans, or even greater, participated in combat in our previous wars, including Korea, WWI and WWII.

Far greater, however, is the invisible epidemic of civilian traumas, which represents a major public health problem in our society today. Childhood abuse, car accidents, combat, rape, assault, and a wide variety of other severe traumas can all be associated with lasting effects on the individual. The American Psychiatric Association defines a traumatic event as something that is threatening to the self or someone close to you, accompanied by intense fear, horror or helplessness. The definition of a traumatic event is outlined in the Diagnostic and Statistical Manual (the bible of the American Psychiatric Association). Exposure to a traumatic event, defined in this way, is required for the diagnosis of posttraumatic stress disorder (PTSD). Researchers make a distinction between traumatic stressors such as these and what we call minor stressors such as stress on the job or getting a divorce. We are not arguing that getting a divorce is not upsetting, but in order to study this area we need to have a definition of a severe stress that is clearly beyond the range of human experience. Nevertheless, as mentioned above, about half of the general population will experience a traumatic stress at some time in their lives. Of these, about 15% will develop chronic symptoms of posttraumatic stress disorder (PTSD)². PTSD affects 8% of the population at some time in their lives³, making it eight times more common than cancer or schizophrenia. PTSD is twice as common in women as it is in men³, which may be at least partially related to higher rates of abuse in women compared to men.

Traumatic stress has a particularly dramatic toll on our littlest citizens, who are not able to protect themselves physically or verbally, and who lack the large and well financed lobbying and advocacy groups that support people who own handguns or who want to sell cigarettes. Studies using large samples of the national population showed that 16% of women were sexually abused at some time before their 18^th birthday⁴, defined as rape, attempted rape, or sexual molestation. These figures add up to the startling fact that about 25 million women were sexually assaulted in childhood in this country, and probably about half as many men. There is documented evidence that one million children are abused in this country every year. In addition to PTSD, trauma survivors are at increased risk for other mental disorders, including depression, alcohol and substance abuse, anxiety disorders, somatic disorders, and dissociative disorders, as well as physical problems including heart disease, cancer, increased infections, gastric ulcers, and cognitive disorders. PTSD is ten times more common than cancer, however our society spends one tenth as much for research in this disorder as cancer. This discrepancy is growing as our senators have recently urged a greater expenditure for cancer, while noone is piping up on behalf of victims of childhood abuse and other traumas.

Posttraumatic stress disorder (PTSD) is an important possible outcome of exposure to traumatic stress. The symptoms of PTSD encompass a broad range of effects on memory, thinking, and behavior. First and foremost is the requirement for a psychological trauma, currently defined as a threat to life or others. The diagnosis also requires one symptom in an intrusive memories category, including intrusive memories of the event, nightmares, feeling worse or increased physiological reactivity with reminders of the trauma, and flashbacks. Three symptoms are required from the avoidant category, including avoiding thinking of the event or reminders of the event, amnesia for the event, decreased interest in things, feeling cut off from others, feeling emotionally numb, or sense of foreshortened future. Two symptoms are also required from a hyperarousal category, including increased startle, hypervigilance, irritability, decreased concentration, and decreased sleep. These symptoms must last a month and are associated with significant disturbance or distress in work, family or social functioning.

Psychological trauma can result in other mental disorders besides PTSD. These include depression, substance and alcohol abuse, anxiety disorders, eating disorders, borderline personality disorder, and somatic disorders. Why some individuals will develop PTSD following a psychological trauma and others will develop depression is not well understood. There is a complex interplay between environment, genetics, and other factors that determines what type of psychiatric disorders an individual will develop. However we do know that there is a great deal of overlap, so that a traumatized individual is most likely to have several disorders, whether it is PTSD and depression, or PTSD and alcoholism, eating disorder and substance abuse, etc. This suggests that there is a central "core" disorder (which we will argue has its basis in a stress-induced neurological deficit) that underlies all of these disorders. According to this argument, there are not separate distinct disorders, but a single spectrum of disorders that have been improperly categorized as distinct disorders by our current diagnostic schema.

Psychological trauma can lead to more than the development of specific psychiatric disorders. It can have a major impact on our total way of viewing the world and ourselves that transcends a specific disorder. We all have an illusion that the world is a safe and just place that we cherish. That's because we need it in order to survive. The world would be a terrible place if we could foresee the future, if we knew everything that was going to happen to us. We wouldn't be able to survive, we would become trembling and terrified infants who were afraid to take a single step on our own. It is our ignorance of the true nature of the world that keeps us sane. Traumatized patients with the diagnosis often do not see the world as a safe place. A woman who has a child snatched from her arms by a kidnapper will forever after live with the knowledge that anyone at anytime could suddenly take another one of her children from her. Someone who was taken hostage will never feel safe walking down a city street. In a sense it is as if they are the ones who see things clearly, who know the truth. And yet knowing the truth makes it impossible for them to live in the world.

It hasn't only been in the 20th century that mankind has experienced psychological trauma. In many ways we are safer now than we have ever been in human history. In ancient times it was not unusual when a city was conquered by neighboring city, that all of the buildings to be razed to the ground, the men were slaughtered, the women were raped and they and their children were sold into slavery, if they were lucky. We take for granted the fact that an enemy will not suddenly ride into our towns, burn down our houses and kill our family. The security we have from such things happening is only a recent thing and represents a small portion of the whole of human history.

In fact psychological trauma has been with us for as long as we have existed as a species. Of course our first experience of psychological trauma was our vulnerability to predators, the natural elements, and our marginal ability to obtain enough food to stay alive and to provide a rudimentary shelter. It was not until man learned how to cultivate the ground and raise food for their own consumption that acts of violence began to be perpetrated by one human being against another. Not until 10,000 years before Christ did mankind develop agriculture, which made possible the collection of food stores in advance, making possible the stockpiling of food and other material goods which could potentially be stolen and plundered from other weaker groups. It is no accident that the rise of socialized man living in organized towns and cities and working together in a collective way to ensure the production of food took place in parallel with the advent of warfare and the wholesale slaughter of peoples. In the beginnings of agricultural society lie the rudimentary elements of what one would call civilization. Agriculture first began in ancient Sumeria in the old cities that emerged between the Tigris and Euphrates rivers. One the earliest activities in these ancient states was the development of irrigation which permitted much larger areas of land to be cultivated over time. When one group of peoples began to acquire more wealth than their neighbors, this led to the desire to take what wasn't theirs, with continuous efforts to attack cities, slaughter the men, and take into captivity the women and children. In fact, most of our history over the last few years has been characterized by this continuous effort to destroy other cities and collect the spoils of war. In the ancient world there were sedentary cities with more established cultures living in the flat and fertile valleys adjacent to rivers, such as Mesopotamia or the Nile Delta, who were conquered periodically by more primitive nomadic groups of Hunter warriors who descended from the North to plunder these cities.

The continued stress of warfare, rape and plunder, and the continuous uncertainty associated with this pattern of living, must have taken a terrible toll on the people who lived in these cities and in these times. However one of the most interesting aspects of the literature of these times is that there are few descriptions of the psychological impact of the experience of combat or other stressors. Most of the emphasis is on the actions of the individual in combat scenarios, stressing aspects such as courage and agility, with a view of the Warrior as hero whose honor comes from performing great deeds in battle, and whose desire is to die gloriously in battle rather than to survive and continue living without land or city. The Warrior Hero actually relied on a continuous state of warfare in order to provide the opportunity to perform great deeds of combat which we help to further his name as a Warrior. Descriptions of the details of combat rarely take the point of view of women and children, other than summary details of their invariably dismal fate, which are presented without any emotional or psychological commentary.

Any descriptions that had to do with the mental life of the Warrior focused on aspects of mental state that were relevant to whether or not the Hero would perform acts on the battlefield that would increase his reputation, such courage or bravery. The literature of Warrior as Hero dealt with mental phenomenon such as matters of character that may affect whether or not the Warrior Hero was able to endure severe hardship during individual combat or tests of endurance. Inherent in this outlook was of course the assumption that members of the Warrior classagriculture would be able to show the necessary strength of character and endurance that was required to prevail in combat or triumph over adverse conditions. It was assumed that members of the lower classes did not have the strength of character or courage to prevail in combat.

In spite of the emphasis on the Warrior, there still are some hints in ancient literature of the negative effects of traumatic stress on the individual. Jonathan Shay has written about similarities between descriptions of the effects of combat on Achilles in the Iliad and the effects of combat that he saw in his veterans of the Vietnam War. Warriors across the centuries had in common a loss of the sense of meaning or order in the universe. The stress of combat and the loss of his friend led Achilles to go beserk in battle and no longer care about his own survival. Achilles felt alienated from those around him and felt like he had lost the sense of meaning in the battle between the Achaeans and Troy.

An emphasis on the Warrior Hero had a beneficial effect for primitive societies. The strong individual who placed greatest emphasis on the success in combat was more useful than someone who focused on internal reflection and self-examination. In fact excessive reflection or sensitivity to others could be detrimental, in that it inhibits decisive action, and the resolution to commit bold and destructive acts of war. It was only in the relative security of fifth century Athens that self reflection could take place to such a degree as to allow the development of philosophers such as Socrates. And this was only a temporary phenomenon that was quickly snuffed out in the ensuing advance of chaos and anarchy that swept up the ancient world and that lasted up until relatively recent times.

It was only with the advent of the 20^th Century that we were able to develop more fully the concept of the life of the mind. This was originally based in the Age of Reason during the 18^th Century which saw the development of scientific thinking in our modern era, stemming from the thinking of the French philosophers Rousseau and Voltaire. Perhaps Rousseau could be thought of as the first psychologist, for he was unique in devoting an entire book to an honest description of his mental state and a description of his thoughts, fears, and motivations, both good and bad, in his work Confessions. This was the harbinger of an increased emphasis on self reflection - and led to an expansion of interest in mental life which ultimately resulted in an examination of mental disorders in the late nineteenth century in the field of medicine.

An important crossroads between mind and brain, psychology and biology lies in the mental health consequences of stress. For the past two centuries scientists and clinicians have been struggling with the potential consequences on mind, brain and body of things that we see, hear, feel, and experience. An important clinical area related to stress is the effects of extreme stressors, such as war, on the individual. During the American Civil War DaCosta¹ first described a syndrome involving symptoms of exhaustion and increased physiological responsivity ("Soldier's Heart" or "DaCosta's Syndrome") seen in soldiers exposed to the stress of war. DaCosta felt that this syndrome was a physical disorder involving the cardiovascular system that was caused by the extreme stress of war. DaCosta's approach was similar to theories of the time advanced by Kraepelin², a Swiss psychiatrist from the late 19^th Century, who also believed that schizophrenia had its basis in the constitution, leading to abnormalities in the brain and physiology. Brain-based explanations of psychiatric disorders left the scene at the turn of the century with the development of psychoanalysis.

The crossroads between the mind and medicine in the late 19^th Century lay in a disease called hysteria. The French physician Charcot brought the description, study and treatment of hysteria into the medical mainstream. Charcot described hysteria as a condition involving symptoms of a loss of feeling and function in a particular part of the body not due to a definable neurological condition that affected women more often than men. Charcot and his colleagues treated hysteria with a new technique called hypnosis. Following up the work of Charcot was a young Viennese neurologist named Sigmund Freud, who felt that mental disorders such as hysteria could be described using the new physical sciences such as physics, which may represent a model for understanding the basis of these disorders in the brain. Much of the physics-based language of what was essentially a pseudoscience would become incorporated into the new discipline of psychoanalysis that was advanced by Freud. The study and treatment of hysteria similarly represented an important foundation for the development of the new science of the mind, which galvanized a new interest in the psychological content of the patients under the treatment of the proponent of this new science, which led to the development of what would be called the talking cure, which we know today as psychotherapy.

Freud working with Eugene Bleuler looked for the causes of hysteria in childhood sexuality. In Freud's first book he described the famous case study of Anna O., who was suffering from hysterical symptoms that appeared to be related to the witnessing of sexual events as a child. Freud originally believed that Anna O. was a victim of exposure to traumatic sexual experiences in childhood. Following this initial observation, he noticed an increasing number of women in his practice who reported exposure to sexual events in childhood. Could it be that Vienna was suffering from an epidemic of childhood sexual abuse? At the time, childhood sexual abuse was considered to be a rare phenomenon. Freud changed his views into the theory that fantasies of childhood sexuality were leading to neurotic behavior in his patients, rather than the reality of childhood sexual abuse. His final formulation of psychodynamic theory did not incorporate environmental events such as traumatic stress in the development of mental disorders.

In retrospect we now know that much of this was probably wrong, that it is highly probable that many of these patients actually were sexually abused, perhaps including Freud's most famous patient Anna O. This is not to detract however from the unique contribution that Freud has made. Freud's greatest contribution was opening up our awareness of the life of the mind, and making us aware of the fact that many of the most important events of mental life are taking place below the surface of the water, in the domain of the unconscious, which is not readily available to conscious reflection. Modern science has in fact proven that the unconscious mind exists, and plays a very important and perhaps dominant role in mental life, thus validating Freud's idea of the unconscious mind. The other major contribution of Freud was to solidify the importance of mental life or psychology as a suitable object of discussion or scientific investigation. Up until that time we were largely operating according to the principles of the warrior class in which action was paramount, and the reflections of the individual were never really part of the common discussion of our culture. This outlook led to the complete exclusion of the possibility of a basis for the brain in behavior any relationship between the brain and the body, for example a connection between mental life and diseases such as heart disease. This view of psychological life as being essentially separated from the brain and the body dominated American psychiatry for the greater part of the century. In many ways psychoanalysis became like a religion that was not challenged by the usual methods of scientific practice, including the requirement to obtain empirical data to support or refute hypotheses. Psychoanalysis became more like a belief system than a scientific theory. In order to be able to provide an authoritative opinion about psychoanalysis it was necessary to become properly trained in this area, which included long years of scientific training, including completion of medical school, psychiatric residency training, followed by psychoanalytic training with a training analysis. Much of the latter part of this training was ostensibly outside of the usual pattern of scientific training so that trainees were no longer able to reenter into the mainstream of the scientific dialogue. As one of my colleagues once told me, "psychiatric training ruins the capacity for logical thought." Freud the neuroscientist would surely have flipped in his grave.

Freud's era of psychoanalysis ushered in a new development in human culture which I call the advent of the Post-Warrior Man. Most of the 20^th Century psychiatry was dominated by the emphasis of psychoanalytic theory on the workings of the mind, to the exclusion of the actions of the individual, even to the perverse extreme of subverting the actions of the individual to a reductionistic analysis based on speculations related to psychological life, encompassed by the term "acting out". This term came from psychiatry and referred to the acting out of mental events in behavior, implying that actions had no real meaning in themselves. Perhaps the supreme embodiment of this figure would be the French philosopher John Pierce Sartre, author of Being and Nothingness and other works. For Sartre and other existentialist philosophers the life of the mind is the only object of serious inquiry and the life of action is not even worthy of discussion. However, civilization never really makes a clear transition from one era to the next. Our current society is not a discrete reflection of either the warrior man or the post warrior man. One only has to turn on the television to see a quick example of the warrior man in action. He does not pause to reflect or be troubled by self doubts or criticisms that could get in the way of doing what is required. We do also have examples of the Post-Warrior man, who is reflected in theater and the novel, and other "higher" forms of our culture. It is safe to say that our current society is a mixture of the two, post warrior man and warrior man, in the same way that many people still believe that the earth is flat, or the sun revolves around the earth, several centuries after we had supposedly been enlightened on these issues by Galileo and Copernicus.

It was only when we began to think about the life of the mind and psychology that we could accept the idea that stress could have a detrimental effect on mental life. However, even with the advent of Freudian psychoanalysis the field of psychological trauma continued to emphasize the mental over environmental events, which continued to be relegated to the back seat of the field of psychiatry. With the advent of the First World War the large number of psychiatric casualties of combat temporally forced attention on the effects of the stress of war and led to the description of "combat fatigue"⁴. Psychiatrists described phenomena such as amnesia on the battlefield, where soldiers forgot their name or who they were. After the war, however, the effects of combat stress on the mind were soon forgotten. With World War II interest in the mental health effects of the stress of war was revived. Again psychiatrists described amnesia and other dissociative responses to trauma^5,6. Internment in German concentration camps was noted to result in symptoms in the survivors including recurrent memories of the camps, feelings of detachment and estrangement from others, sleep disturbance and hyperarousal, as well as problems with memory and concentration⁷.

The experience of the Second World War was still fresh in the minds of psychiatrists when the first edition of the Diagnostic and Statistical Manual (DSM-I) was formulated in 1952. This led to the addition of Gross Stress Reaction in the DSM-I. Gross Stress Reaction described a series of stress-related symptoms in response to an extreme stressor that would be traumatic for almost anyone. This may have stemmed from the experience of military psychiatrists in WWII, who observed during the war that many normal men were having mental breakdowns in the face of combat. However, Gross Stress Reaction specified that the individual must have a normal pre-stressor personality, and that the symptoms should naturally resolve with time. This disorder did not take into account the fact that individuals with a pre-existing psychiatric disorders may develop a new disorder that is specifically related to the stressor, or that acute responses to stress can translate into long-term pathology. It is as if Gross Stress Reaction was a response to the reality that extreme stressors such as war can lead to psychiatric outcomes that are not secondary to "bad personalities" (military psychiatrists in WWII had tried in vain to find pre-military personality traits that would help them predict who was most vulnerable to the stress of combat). Embodied in Gross Stress Reaction was the ambivalence that has pervaded psychiatry until the current time about whether stress has merely transient effects, or whether it can lead to permanent psychopathology.

It was perhaps the forgetting of the horrors of WWII that resulted in Gross Stress Reaction being dropped from the DSMII in 1968. It wasn't until another major conflict, the Vietnam War, that mental disorders related to traumatic stress were once again recognized by psychiatrists. This time, however, there was a greater recognition for the lasting effects of traumatic stress on the mind. Researchers such as Charles Figley⁸ argued that the stress of war in and of itself led to psychopathology as opposed to factors such as "bad character" (preceding the war). This was the background leading to the inclusion of PTSD (with both acute and chronic types) as a disorder in the DSMIII in 1980. With DSMIII-based PTSD we finally had a diagnosis that recognized the lasting pathological effects of traumatic stress. Because of the specific way in which PTSD developed, it is unique amongst psychiatric disorders in requiring exposure to an extreme stressor. Acute Stress Disorder (ASD) was introduced as part of DSMIV in 1994. This reversed the trend of DSMIIIR, which did not include Acute PTSD or any acute stress response diagnosis, and harkened back to the Acute PTSD in DSMIII. ASD is of duration of less than one month, and (like PTSD) requires exposure to acute threat to life with fear, helplessness or horror. In addition, ASD requires three dissociative symptoms (numbing, derealization, depersonalization, amnesia, or being "in a daze"), one or more of each of the PTSD reexperiencing, avoidance, and hyperarousal symptoms, and functional disturbance (as in DSMIV PTSD).

The dominance of American psychiatry by Freud's theories lasted until the advance of biological approaches to psychiatry, which have become increasingly prominent over the past 30 years. Biological psychiatrists aimed to replace Freud's theories of psychopathology (based on ideas of imbalances of psychological forces) with what they felt was a more scientific approach. In their view, psychopathology was secondary to disruptions of physiology that had their foundation in genetic vulnerability. This framework placed great emphasis on genetic abnormalities leading to physiological changes, with their phenomenological expression in psychiatric disorders. In the early phase of biological psychiatry, there was a great emphasis on finding the genetic basis for psychiatric disorders, and little emphasis on the role of environment in the genesis of psychopathology. As is often true in the history of the development of ideas, the biological psychiatrists effectively leaped backward over 50 years of psychoanalysis to psychiatrists such as Kraepelin (1919). He also believed that psychiatric disorders had their basis in constitutional abnormalities that had their expression in the brain, and performed neuroanatomical studies of the brains of schizophrenics in order to find a lesion to explain their illness.

The biological psychiatrists who used this model, however, were really not much different from the psychoanalysts who preceded them. Both groups gave little or no credence to the role that environment could play in the development of psychiatric illness. Biological psychiatry emphasized the deterministic effects of genetics, while psychoanalysts focused on unconscious mechanisms upon which the environment had little impact (e.g. at one time the idea that children should be observed in order to understand their internal psychology was considered radical). Thirty years after the start of the biological revolution in psychiatry, we still haven't found the gene for schizophrenia or mania. It is clear that genetic factors do play an important role in psychiatric disorders. Most likely, a combination of genetic and environmental factors, of nature and nurture, is involved in the development of psychopathology. In terms of possible environmental causes of psychopathology, stress is a good candidate.

One of the most important brain areas that mediates, and in turn is affected by, the stress response is the hippocampus. The hippocampus plays an important role in new learning and memory (Zola-Morgan and Squire 1990). This function is critical to the stress response, for example in assessing potential threat during a life-threatening situation, as occurs with exposure to a predator. Alterations in memory form an important part of the clinical presentation of patients with stress-related psychopathology. PTSD patients demonstrate a variety of memory problems including deficits in declarative memory (remembering facts or lists, as reviewed below), and fragmentation of memories (both autobiographical and trauma-related). PTSD is also associated with alterations in non-declarative memory (i.e. types of memory that cannot be willfully brought up into the conscious mind, including motor memory such as how to ride a bicycle). These types of non-declarative memories include conditioned responses and abnormal reliving of traumatic memories following exposure to situationally appropriate cues (Brewin et al 1996).

Recent findings that environmental events such as stress can lead to long-term changes in brain areas such as the hippocampus has potentially radical implications for how we think about mind, brain, and questions of mental health. The concept that what you see, think, and feel may change brain function and even structure could force us to rethink many issues of mental health. Perhaps it is time to think of victims of psychological trauma not as people with bad characters or bad luck, or subjects of our pity or charity, but rather as individuals with neurological disorders that have been caused by their life experiences, in much the same way that, for examples, many people with epilepsy have brain lesions that cause their disease. In fact, using the example of epilepsy, in the past century this disorder was felt to be related to bad spirits, and it was only with advances in medicine and neuroscience that we were able to find the cause. We may be at a similar threshold with regard to mental disorders, in the initial stages of identifying a neurological basis for disorders we previously thought of as purely "psychological". Recognizing that environmental events can lead to neurological disorders is in many ways a return to the original ideas of Freud. As Freud started out doing, I now propose to describe mental disorders as alterations in physical phenomena (which he described using the terms of 19^th century physics, and we now describe with neuroscience and neuroanatomy). Like Freud's believed originally, in this book I propose that early childhood trauma is an important determinant of many mental disorders. I will also propose that dynamic mental life plays a role in "real" mental disorders (thoughts, feelings, meaning of events) as opposed to mental disorders being primarily fixed predetermined conditions.

The requirement of exposure to a traumatic stressor for the diagnosis has led to an odd dichotomy over the years between PTSD and other psychiatric disorders. There are other disorders that are strongly linked to trauma, most notably Dissociative Disorders, Borderline Personality Disorder, alcoholism and substance abuse, somatic disorders, eating disorders, anxiety, and depression. However, the relationship between trauma (especially in early childhood) and development of these disorders has been repeatedly documented. There is also considerable overlap in symptoms and so-called "co-morbidity", e.g. between PTSD and dissociative disorders, or between PTSD and alcohol/substance dependence and depression. These findings raise the question about whether these are in fact separate disorders, or whether they are part of a spectrum of psychiatric disorders.

In this book I in fact argue that these disorders are part of a trauma-spectrum group of disorders that all have a relationship to a common stress-induced neurological deficit. This idea is based on several pieces of evidence. For instance, all of these disorders mentioned above which I include as "trauma spectrum" have in common a high association with exposure to traumatic stress, especially childhood abuse. PTSD requires for its diagnosis exposure to traumatic stress, and essentially all patients with severed Dissociative Disorders such as Dissociative Identity Disorder have been abused in childhood. Eighty percent of patients with Borderline Personality Disorder have a history of childhood abuse, and other studies have found elevated rates of childhood abuse in patients with alcohol or substance abuse or dependence, or panic disorder and depression.

There also is considerable overlap in the actual symptoms listed under the trauma spectrum disorder. For instance, many symptoms of depression are equivalent to symptoms of PTSD. Psychomotor agitation can be rephrased as hyperarousal, and hopelessness as a sense of foreshortened future. Other symptoms that are identical in the criteria for depression and PTSD include decreased sleep, decreased concentration, and feelings of being cut off from others. In fact the only symptom of depression that is not included in the criteria for PTSD is depressed mood, and on a clinical basis feelings of depression are common in patients with PTSD. The only symptoms of PTSD that are not part of depression are increased startle, feeling on guard, flashbacks and amnesia. There are also important overlaps between PTSD and other disorders. For example, flashbacks and amnesia are essentially dissociative phenomena. Dissociative responses to trauma have been linked to both long-term dissociative disorders as well as PTSD. Some studies have shown that flashbacks in almost all cases meet criteria for a panic attack, and depersonalization and derealization (dissociative symptoms) are in fact listed in the criteria for a panic attack. Disturbances of identity are relevant to borderline personality disorder, and dissociative responses are common in patients with this disorder, often leading to self-injurious behavior, which patient claim "breaks" dissociative states.

[diagram of "pizza slide"]

Another disorder which should definitely be included in the trauma spectrum disorders is Acute Stress Disorder (ASD). The development of ASD in the DSM has an odd history of its own which is partially related to the abandonment in earlier versions of DSM of a diagnosis to capture the acute trauma response. I would propose that ASD and PTSD should be considered to be closely related, if not identical, disorders. Their criteria should therefore be made to be consistent with one another. Considering the important role of dissociation in the acute stress response, and the relationship between ASD as currently configured and PTSD, inclusion of dissociative symptoms in the diagnosis of PTSD should be considered. In addition, based on the propensity of PTSD patients to have dissociative responses to subsequent traumas and even minor stressors (i.e. amnesia, depersonalization and derealization), it makes sense to create a similar dissociative cluster for chronic PTSD. This cluster would also include symptoms such as emotional numbing. With incorporation of amnesia, depersonalization and derealization into chronic PTSD, these could be dropped as separate diagnoses in the Dissociative Disorders that are theoretically unconnected to trauma. Dissociative Identity Disorder, a more extreme response to stress, could be maintained as a separate disorder.

An accurate description of psychiatric responses to trauma might be served by the development of a new category of Trauma Spectrum Disorders. This would include both acute PTSD (the current ASD) and chronic PTSD (using revised criteria to be in line with ASD), Dissociative Identity Disorder, conversion disorder, adjustment disorders, and possibly Borderline Personality Disorder or other proposed disorders such as Traumatic Grief. Other disorders linked to stress, such as depression, panic disorder, eating disorders, anxiety, and alcohol/substance abuse, may not fit as neatly into the Trauma Spectrum Disorders since there are obviously some patients with these disorders who do not have a history of trauma.

The development of a Trauma Spectrum Disorder approach would represent an obvious divergence from the thrust of psychiatric diagnosis, at least in America, over the past 20 years. Much of the recent history of psychiatry has represented an emphasis on the evaluation of psychiatric diagnosis, with the assumption that psychiatric diagnoses represent discrete entities, much as medical disorders represent discrete disorders. If there is an increased overlap between different psychiatric disorders, it is assumed that patients have "co-morbidity" rather than that the diagnostic schema is not adequate to describe the phenomena. However the absurd rates of "co-morbidity" force us to the realization that many psychiatric disorders, especially the Trauma Spectrum disorders, may not represent discrete disorder, but rather are aspects of an array of psychiatric outcomes that have historically been artificially divided into discrete disorders.

Stress-induced neurological disorders may underlie Trauma Spectrum Disorders. A common neurological deficit may be the cause of the considerable overlap between these supposedly discreet disorders. According to this idea, stress-induced deficits in specific brain areas, such as hippocampus and possibly prefrontal cortex, is the neurological basis of the disorder. Why some individuals develop depression and others PTSD may be related to severity of the injury, interaction with genetically determined personality traits, developmental epoch when the trauma occurred, or some combination of all of the above. In this book I will explore the critical question, does stress damage the brain? And I will outline the possible implications a stress-induced neurological deficit may have for psychiatric diagnosis and treatment, most notably the idea of a unifying group of psychiatric disorders under the umbrella of the Trauma Spectrum Disorders. But before I go further on this topic I will lay the groundwork for a discussion of the idea that stress can cause brain damage by reviewing the background behind the incredible revolution that has taken place in the science of the brain over the past two decades. In particular, I will highlight two important areas, namely genetics and brain imaging, that have provided important tools that have greatly expanded our knowledge of psychiatric disorders.

About the Author

J. Douglas Bremner, M.D., is Director of the Emory Center for Positron Emission Tomography at Emory University Hospital, Director of Mental Health Research at the Atlanta Veterans Administration Medical Center, and is the editor of Trauma, Memory, and Dissociation and Posttraumatic Stress Disorder.

ISBN: 0-393-70474-2
April, 2005
Paperback, 311 pages