Raquel E. Cohen MD, MPH

March 2008


            After reading Dr. Robert Sapolsky’s Why Zebras Don’t Get Ulcers[1], I could only wish this book had been written when I started helping survivors of natural disasters many years ago.  My observations of the reactions and behavioral responses of survivors and workers after natural disasters were strongly supported by the research findings on the effects of stress presented by Dr. Sapolsky, the John and Cynthia Gunn Professor at the Stanford University School of Medicine Department of Biological and Neurological Sciences. Looking back over thirty years in the field of disaster intervention, the book provided me with insights into behaviors I had noted in my interactions with survivors.


            The book motivated me to write this article to address the question “How can the findings presented in the book better help disaster assistance workers to understand survivor’s reactions?”  I believe the answer readily can be found by applying Dr. Sapolsky’s stress response “explanatory hypothesis” as a way of understanding survivors’ post-disaster behaviors.  I also hope this article will disseminate to disaster workers the contributions contained in Dr. Sapolsky’s evidence-based findings. I believe these findings can assist workers not only in understanding the psychophysiology of the stress response and coping mechanisms, but also to more effectively find modalities to better address negative responses and promote better coping behaviors in themselves and survivors.




            Dr. Sapolsky’s book presents a number of themes through which he maps the pathways of the physiology and psychology of stress systems and coping behavior.  This article will discuss those themes that apply to the responses and reaction patterns I have observed in survivors and disaster workers overwhelmed by the tragic consequences of the event..   During thirty years of working in the area of mental health intervention after a natural disaster I have documented on my web site ( many experiences that serve as supporting data to my understanding shared now in this article.  While I will not be quoting directly from Dr. Sapolsky’s text, it should be understood that all physiologic data is derived from his work, and supporting data and references can be located there.




            This paper will utilize certain chapters of the book to track post-disaster phases, which will hopefully offer workers knowledge to help them understand theirs and survivors’ reactions as time processes after the disaster. Disaster program planning normally identifies the weeks and months following the impact of the disaster as the:


·        impact phase

·        post-impact phase

·        short time post-impact

·        Long-time post-impact phase.




            During the 20th century, the study of the body’s physiological responses to stressful events has become a valid discipline. As a result, there is now much more data regarding physiological, biochemical, molecular and social information describing the health and behavior of individuals. Still lacking, however, are studies of the interaction between the systems of the stress response among survivors, which in the future will help us better understand their post-disaster behavior.


            How do our bodies adapt to the multiple trauma and emergencies that suddenly disrupt and change survivors’ lives after a tornado, earthquake or hurricane? Why do some survivors cope and eventually emerge with few troubled memories while others develop physical and psychological traumatic syndromes? Can we ameliorate or prevent these sequels if we better understand the mechanisms of stress-response on their bodies and psyches? The findings presented in Zebras begin to answer these questions.  


            One must start with an understanding of some basic physiologic systems that are balanced, directed, and controlled by the brain in seeking homeostasis of body systems.  An outside stimulus that disrupts this balance (a stressor) produces the stress response, which is the body’s attempt to reestablish homeostasis. A stressor can also be the anticipation of a future traumatic event. For example, when developing training programs before the Florida hurricane season every year and encouraging preparedness, state officials are actually elevating the stress level of some citizens, who may then be more vulnerable if a disaster occurs. However, to neglect such training and outreach might result in many more deaths and injuries. This represents a balancing act on how to prepare a population without increasing its fear and anxiety.


            A recent concept to describe this homeostatic balance refers to “allostasis”. The term is used to describe the brain’s capacity to coordinate simultaneous body-wide physiological and psychological changes in an attempt to regain homeostasis. Repeated triggering of the stress-response, or the body’s inability to regain homeostasis after a stressful event can actually cause more physical and psychological damage than the stressor itself.


            It is not surprising that the physiological effects of a stressor will be modulated by psychological factors, especially in how the same event is perceived by different survivors. This psychological distortion explains the experience I had working in a shelter after a devastating tornado. Interviewing survivors about their emotional status, I received answers that ranged from mild complaints to genuine pain at the loss of their home. I was aware that the external reality of the destruction and what I was hearing and observing in the shelter did not fit my expectation of the level of the survivors’ suffering.  After working in various settings after natural disasters, I realized that survivors appraised their losses differentially and defended with individual coping processes, from awareness of reality checks. This lesson was forcefully brought home to me when I accompanied a survivor who had appeared calm in the shelter to her destroyed house. As she contemplated the remnants of her home, she began to cry hysterically and fainted in my arms.


            This and other experiences support the data that a variety of psychological factors can modulate the stress-response in the early post-disaster phases. The ability of the disaster worker to recognize those psychological variables, understand how they will affect the stress response, and develop interventions to emphasize the beneficial variables therefore becomes a critical skill. Several such interventions are described in Dr. Sapolskly’s books. One technique is teaching survivors to relieve frustration by using imagery and imagination to attenuate the pain and tension, instead of aggressively discharging that frustration on a weaker individual, as has been observed in post-disaster situations. Perhaps one of the strongest areas of help is using and accepting the links and bonding found in social support. Many research findings attest to the fact that the better the “fit” and depth of protective relationships are in which an individual is involved, the less the pain and stress of a traumatic experience will be. I have observed this in disaster assistance programs that were sensitive to these factors, especially those programs that worked to find lost family members, such as the Red Cross bringing members of the armed forces stationed in foreign countries back to US to help elderly survivors or find lost or wounded children after an earthquake or tsunami.


            One factor that can modulate the stress-response is predictability. Being forewarned of the possibility of the stressor, its characteristics, duration, and effect, allows a modulating process to develop that prepares individuals to face the situation. The process allows the potentially affected population to strategize efforts to cope in the event the disaster occurs, and permits habituation if the stressor is repeated multiple times. This modulating factor can be seen by contrasting Florida, where hurricanes are expected and prepared for every summer, with California, where the threat of earthquakes is unpredictable. 


            Another factor in modulating the severity of the post-disaster stress response is the ability to rehearse the response through role playing, emphasizing the belief that a survivor will have some control after a disaster. Acquiring knowledge of these techniques can help authorities planning disaster programs. Unfortunately, many of the programs that are developed during the first weeks post-disaster to assist with shelter, housing, or offering psychosocial assistance are not sensitive to the survivors’ need to believe they have some control by adequately informing them about predictable bureaucratic procedures.  The book presents these issues with a caveat that stressors and coping mechanisms must be examined taking genetic factors, personality, and past experience into consideration when making the determination of the vulnerability of an individual, and predicting what illnesses or psychological disorders they may suffer. These sets of data can be used as we approach a survivor post-disaster even if we cannot be assured of their effectiveness.  I would suggest we should include this information to increase the chances that early intervention may be helpful in understanding the reactions of the survivor  and of the worker as more evidenced based data emerges.




            The short-time post-disaster phase comprises several months after the disaster, when shelters begin to close, agencies discontinue their presence in the devastated region, and early activities to rebuild the community start.   Most survivors will have been relocated and now face daily stressors of multiple varieties, which produce frustration over ambiguous outcomes, unfulfilled promises of builders and various contractors, promised government subsidies and assistance that are postponed or fail to materialize, and jobs that many times disappoint.   Also many of the mental-health disaster workers who were deployed to the disaster area finish their responsibilities and refer “cases” to the overwhelmed agencies  to follow through with the assistance.  Survivors can pay a very high emotional price for these conditions. Research findings indicate that psychologically affected survivors run the gamut of affective and post-disaster stress syndromes, with depression, loss, disappointment and stress inextricably linked. It is impossible to understand either the biology or psychology of depression of survivors without recognizing the critical role-played in the affective syndromes by loss and stress.


            In disaster where loss is a predominant component, I have observed the typical coping mechanisms expressed by survivors: disbelief followed by yearning to recoup the loss of their familiar environment, which will likely never be the same, followed by anger, despair, and depression as reality sets in, hopefully leading finally to acceptance. At a physiologic level the genetic/neurochemical disorder underlying the vegetative symptoms and psychomotor retardation, including the difficulty of returning to usual sleep and eating patterns, indicates the radical change in the survivor’s physiology. Studies of depression reveal that two independent physiologic trends tend toward collapsing into one inverse relationship with too few positive emotions and too many negative ones.


            The roller-coast events in the daily lives of survivors can prevent healing and even a moderate return to homeostasis for months. Sadness, grief, and guilt are part of this post-disaster stage as the survivors deal with their losses. Guilt often must be dealt with as survivors realize they have saved themselves, their family, or their possessions while a relative or neighbor has lost everything. One tragic example were the expressions of guilt shared with me after the destruction of Armero, Colombia after the Volcano Nevado del Ruiz buried 20,000 citizens with lava, rocks, mud, and debris. The survivors had to be plucked one by one by helicopters, saving only those residents who were able to stay in the mud up to their necks and breathe long enough. Many of these survivors told me that they could not forgive themselves for letting go of individuals who they were holding and seeing them submerged in the boiling muck. Understanding the terribly sad and painful experiences that follow the impact and post-disaster phase clarifies the fact that these difficult, painful, and frustrating experiences start the cascade of stress reactions, influencing the complex network of neurotransmitters impacting on the emotional and cognitive systems that produce depressive symptoms. 


            One question that must be investigated is why some survivors show different levels and protractedness of depressive signs. It has been clearly shown that depression has a genetic component, so the need to identify specific gene-variant DNA that codes for proteins increasing the risk for depression is equally clear. Research findings indicate that stress and glucocorticoids join in predisposing a person toward depression due to genetic influences making them more vulnerable to triggers found in traumatic environmental circumstances. One common feature of depression is an overactive stress-response, representing an inability of the brain to shut down the cascade of neurotransmitters in the presence of a strong stress signal. Stress has been shown to cause many of the changes in other neurotransmitter systems and their interaction with receptors causing abnormalities in their processes.


            Helpless behavior is shown as a response to absence of control, predictability, and an inability to express frustration resulting from a belief and perception that life is worsening. Research points to several sources of vulnerability which produce this behavioral reaction.  I have found this helplessness in several experiences post-disaster, the most dramatic exemplified by a “post-disaster village” I revisited in the region of Managua, Nicaragua several years after a major earthquake flattened that area in 1972. Many of the survivors’ modest houses had white flags in front, signaling a need for governmental assistance due to their incapacity to fare for themselves even years after the event.


            Differing levels of anxiety observed in survivors for several months post-disaster manifest another general response to stressors. Different expressions of anxiety have been labeled as generalized, acute, or phobic anxiety disorders. In disasters, survivors manifest a free-floating type of nervousness, fear, and tension that resembles anxiety. It manifests according to the aftermath quality of their surroundings during reconstruction of their lives. In situations where survivors do not have control or accurate information, where rumors continually supersede each other and expectations are endlessly frustrated, a sense of dread and foreboding is constant. In these situations, survivors are prone to overestimate risks and likelihood of a bad outcome.


            Two important research areas aid in exploring the sources of anxiety: life experiences with their learned and conditioned associations, and individual genetic/personality characteristics. Research indicates the circular effect produced by the link between the brain’s sympathetic system, composed of the amigdala and the frontal lobes. Stress and glucocorticoids impact on synapses in the amigdala, making them more excitable and proliferating the number of neurons that connect the cells to each other. This enlargement of the amigdala causes it to become more excitable and anxiety prone. One outcome of these findings is research reporting that utilizing drugs to block the sympathetic nervous system in an individual who has suffered a major trauma decreases the potential of the person consolidating a traumatic memory.




            During the post-disaster long-term phase, the region begins to acquire a rhythm and structure, and many activities revert to familiar patterns or solidify into new ones. Most survivors have been able to process the traumatic reminders and develop coping capacity. As survivors begin to return to their neighborhoods to rebuild their homes and inventory their needs, different stressors will interact with their capacity to modulate their biologic and psychological stress responses. The survivors now face a multi-tasking effort to restore their structural, social and psychological surroundings, as well as to rebuild shelter and economical stability. The sources of stress are manifold not only due to the tasks required, but also because of the bureaucratic hurdles that must be surpassed to obtain the resources needed. By now, many of the agencies that were present during the immediate post-impact phases have ceased operations, and the citizens are left to fend for themselves. Levels of stress vary depending on the amount of frustration encountered.


            One approach to lowering survivors’ stress is to increase their capacity to deal with the obstacles faced by encouraging, assisting, guiding and educating them to master the needed tasks. Helping them achieve this perception of control and self-efficacy, and allowing them to become more active and knowledgeable about the choices regarding the variety of issues they face, clearly acts to lower stress. This intervention technique should also be conveyed to all post-disaster workers and agencies that are helping survivors reconstruct their homes and neighborhoods. It is important to recognize that by this time workers in agencies, administrators of programs and other responsible government representatives have also suffered from the increase demands and critical frustration of the survivors.  I had the opportunity to observe this reaction in a head nurse with whom I was working five months after the Managua earthquake. She told me how shocked she was to feel homicidal impulses toward a looter she found rummaging through her mother’s destroyed house, and how glad she was that she did not own a gun, as she was sure she would have used it. For days after, she was surprised she could have acted on her rage, having always considered herself a caring and sensitive person.


            The psychological and physiological effects of the catastrophe are magnified in vulnerable and at risk groups. For multiple reasons, these individuals cannot overcome the effects of the disaster, displaying the gamut of chronic conditions, including Post Traumatic Stress Disorder. This condition is characterized by individuals displaying several symptoms, including an inappropriate startle reflex and problems with memory and concentration. Several brain-imaging studies of individuals suffering PTSD support the hypotheses explaining this syndrome, including findings of a smaller than average hippocampus in individuals who have experienced repeated, chronic traumas. It is suggested that the effect of physical or psychological trauma stimulates the adrenal gland to secrete large amounts of glucocorticoids that can affect the neurons of the hippocampus, resulting in shrinking or destroying the connections between its branches. It can also affect the regeneration of neurons or show  variability of sensitivity in the receptors. Further investigation is needed to look at cellular mechanisms involved in experience-induced neuronal plasticity underlying learning, anxiety and fear.[2]  This change of connections in the brain could clarify some of the symptoms in the cognitive and affective behavior following long and consistent trauma.




            The consequences on the body’s vital organs resulting from chronic releases of the multiple chemicals of the stress reaction can be severe and can lead to multiple disorders or diseases. How can a survivor, having saved himself from the impact of a destroyed home but hearing the rumble of another tremor, finding himself without water or electricity, at the mercy of looters, and surrounded by dire and terrifying rumors modulate the stress response? How does a devastated population, knowing they live in a country with few resources and a lack of emergency governmental assistance, deal with this? Sadly, this is the reality of many underdeveloped countries. Can our increased knowledge of the causes and effects of stress assist us in protecting survivors in catastrophic situations? Can we develop better methods to ameliorate the consequences of disasters? We have learned that critical modulating factors such as control, predictability, social support, and outlets for frustration can to some degree buffer survivors from the consequences of stressors. 


            This critical amount of physiological post-trauma data raises an important question: can this understanding be applied to the multifactor groupings that need help after a disaster? Can we develop common intervention techniques for these differing individuals from mostly lower socio-economic strata (individuals with sufficient resources find help for themselves), diverse health levels, and different religions, traditions, gender, and ages?  Can we be assured that if disaster workers help survivors achieve a sense of control, of predictability, of appropriate support systems, of lowering their frustrations with bureaucracy or the lack of jobs, their stress levels will be lower?  Can workers help themselves by  programs that apply these conditions? Currently, we cannot be sure this will be the case, but we can start with the assumption that stress-response manifestations can be predicted as determined by current research, while at the same time being alert, respectful and sensitive to variations in those responses. Will this amount of data suffice to convince the authorities that the effects of stressors following a disaster are a critical public health issue? Will it allow public health professionals to advocate for more effective services for survivors? Only time will tell.




            To review the phases of post-disaster processes, the event initiates acute stress reactions that prepare the survivors to identify and find ways of coping with danger. Coping capacity and processes will vary according to personal styles and different circumstances faced by the survivors. While multiple variability within the degrees of vulnerability, physical, and psychological factors make it difficult to generalize, there are some universal coping methods.  During the acute reactions in the initial post-disaster stages, intense denial and rationalization seem to be the most effective mechanisms at reducing stress. Research indicates that personality characteristics and past learned experiences are involved in successful coping. During the short-term post-disaster period when survivors are still living in shelters or being assisted by disaster workers in their neighborhoods,, we can differentiate several capacities for coping, identify stress reactions such as depression and anxiety, and note early indications of dependency and helplessness. Techniques to intervene during these first weeks are being explored to mitigate survivors’ stress responses and support their return to homeostasis.  The common denominators of such procedures include safety, support, information, connectedness, and guidance, all categorized as First Aid Assistance Intervention. These strategies are helpful in mitigating the effects of the stress response and helping the physiologic and psychological coping mechanism to return to homeostasis.  There is a consensus that these techniques do no harm and tend to mitigate negative reactions.


            With the passage of time, the needs and responses of survivors will vary according to the problems they face. Crucial variables will include shelter and economic opportunities. Stressors and stress responses are individual characteristics and will necessitate specific management as each survivor’s status is identified during the assistance efforts. What is now well understood is the fact that the post-disaster recovery phase can be as stressful as the disaster itself, and must be identified as such in order to offer survivors a possibility of recovery.




            A summary of Dr. Sapolsky’s final conclusions in the book offers a foundation based on current knowledge of the physiologic and psychological stress-response which can be used to develop helpful strategies to be applied in post-disaster assistance programs for survivors and disaster workers.


1. First, the use of denial as a coping mechanism to deal with aoverwhelming, instant trauma should be regarded as a healthy coping process. Given what we know about trauma, stressors, stress responses, and the sequelae associated with catastrophic disasters, assistance teams should extend hope balanced with a realistic assessment of the difficulties that will be encountered in the future.


2.  Helping survivors identify small components of their lives that can be controlled and then, step-by-step, furthering their capacity for self efficacy to control their future while at the same time assisting them to support uncontrollable realities.


3.   Monitor the flow of information both in timing and quantity as a way of limiting the amount of stress that knowledge about the reality of the situation will produce. Determining the capacity to deal with stress over time may be a function of post-disaster intervention.


4.  Help in finding appropriate outlets for the inevitable frustration that accompanies the aftermath of disaster consequences may mitigate the anger and rage felt by the survivor facing insurmountable barriers.


5.  Assist survivors in using all their social bonding for their benefit by helping them realize how important and beneficial such bonding is for their mental health. Connectedness and strengthening social bonding should permeate all efforts post-disaster.


 6.  Help survivor and rescue personnel become aware how their thoughts, emotions and behavior can enhance their coping capacity and assist them in mitigating the effect of the stressors produced by the impact of the disaster.


            Finally, I would like to thank Dr. Sapolsky for allowing me to use his data and the very helpful content of his books in adapting this information for the benefit of future workers in the area of disaster assistance.  


[1] Sapolsky, Robert M., Why Zebras Don’t Get Ulcers, 3rd Ed., Owl Books, New York, NY, 2004

[2] Sapolsky, Robert M., Monkeyluv, Scribner & Sons, New York, NY, 2005