Data collected by the National Center for Health Statistics (NCHS) and the Census Bureau revealed that over 40 percent of the U.S. population in the third week of July 2020 exhibited symptoms of anxiety or depression disorder, which are clinical diagnoses. The comparable figure from the same survey given in the January–June 2019 time frame was 26 percent. Symptoms of anxiety or depression disorder included frequently having little interest or pleasure in doing things; feeling down, depressed, or hopeless; feeling nervous, anxious, or on edge; and not being able to stop or control worrying.

A second poll conducted by the Kaiser Family Foundation (KFF) and released on April 24, 2020, found that over half of U.S. adults (56 percent) report that worry or stress related to the coronavirus outbreak has caused them to experience at least one negative effect on their mental health and wellbeing, such as problems with sleeping or eating, increased alcohol use, or worsening chronic conditions. 40 percent report that worry or stress has led to problems with their sleep, while 15 percent had difficulty controlling their temper and 13 percent reported increases in their alcohol or drug use. (The reason that the KFF figure is higher than the Census Bureau figure is likely that the KFF was not probing for clinical diagnoses, which is a more severe condition than that measured by the KFF poll.)

The list of mental health issues below is familiar to many people during this pandemic.

• Depression. Individuals suffering from depression often lose their self-confidence and feel overly vulnerable or incapable. Sometimes, they exhibit emotional dullness or numbness. Emotions such as pride, shame, hope, grief, and gratitude are sharply attenuated, even when circumstances or events occur that would normally spark such emotions. Social companionship may become less of a priority, as individuals become more withdrawn and silent and they seek to isolate themselves. Individuals may be less talkative than usual and show limited response to jokes or cries. Personal hygiene and grooming also assume less importance, and the individual may present as more disheveled in appearance, with little professional bearing. 

• Anxiety. Anxiety is characterized as a disproportionate response to uncertainty about potential threats. People who suffer from anxiety are often fearful, restless, preoccupied with worst-case scenarios, unable to relax, or physically agitated.

• Mental distraction. People who are mentally distracted often suffer from forgetfulness and an inability to concentrate. They may have difficulty sorting out priorities or starting routine tasks. They may be excessively concerned with minor issues and exhibit a tendency to do familiar tasks and a preoccupation with familiar details. Conversely, they may have a hard time performing unfamiliar tasks. They may be restless, wandering aimlessly. Attention spans may be short, making it difficult for them to understand what others are saying. They are often unable to take the initiative in starting any activity, or they may take a long time to react to occurrences that normally require prompt attention.

• Irritability and angry outbursts. Mild irritability may include angry looks, sharp words, tears, or profanity in response to normal, everyday comments or incidents or relatively slight frustrations or provocations (e.g., the closing of a window, an accidental bumping, or just normal verbal interactions). More severe irritability may include sporadic and unpredictable explosions of aggressive or violent behavior.

• Sleep disturbances and fatigue. With sleep disturbances in play, falling asleep is difficult even when the objective situation is safe for sleep. The individual may awaken frequently and have difficulty going back to sleep. Sleep may be accompanied by nightmares or other terror dreams, involving, for example, images of oneself or one’s loved ones dying. Sleep of this nature is not restful, and the individual may wake up as tired as when that person went to sleep. Individuals may also sleep excessively—significantly more than seven to nine hours per day. When these individuals are awake, they often exhibit low energy levels when they expend a great deal of effort on only a few or minor tasks.

• Hypervigilance. Hypervigilance is characterized by excessive sensitivity (such as a fight-or-flight response) to external stimuli that might signal danger, even if that stimulus is associated with a benign object, event, or person. Hypervigilant individuals often overreact or misinterpret unexpected noise, movement, or light. They may even overreact to reassuring information, perceiving such information as threatening.

Most interesting about the list of symptoms above is that it is taken from U.S. Army manuals intended to provide leaders of combat units with information about how to identify stress resulting from combat operations. U.S. Army Manual ATP 6-22 (A Leader’s Guide to Soldier Health and Fitness) describes combat stressors as “singular incidents that have the potential to significantly impact the unit or soldiers experiencing them,” whereas operational stressors include “multiple combat stressors or prolonged exposures due to continued operations in hostile environments [emphasis added].” Sometimes, these stressors are related to multiple potentially traumatic events, which are events that are “perceived and experienced as a threat to one’s safety or to the stability of one’s world.”

Reactions to combat and operational stress are not the same as post-traumatic stress disorders (PTSDs). That said, they may well share some symptomatic similarities, and the distinction between the two are not always clear. One key difference is chronological sequencing—in PTSD, symptoms of the disorder appear after the event(s) occur, though the definition of “after” may be somewhat fuzzy given the ongoing nature of operational stress.

A personal anecdote is relevant here. Much of the period between March 2020 and the present has been spent under a shelter-in-place order of some kind. Individuals, especially those in high-risk groups (I am a member of one such group), are advised to stay home as much as possible to avoid exposure to others who may be carriers of the SARS-CoV-2 virus that causes coronavirus. However, it is also necessary to venture outside for exercise, such as walking.

I live in an urban neighborhood (San Francisco) and when I go outside for a walk, I find I am constantly scanning the streets and sidewalks for other human beings. My immediate reaction to the sighting of any human being is to react to that human as a potential threat. I consciously evaluate the threat by trying to determine if that human being is wearing a mask properly. If my answer is negative, I immediately seek ways to escape—turning around, crossing the street, or allowing the person to pass but with my back turned and holding my breath for a few seconds after the person has passed.

I used these words advisedly—an unmasked person is a threat, and an encounter with that individual could kill me if the virus is present in his or her body. Given the incidence of coronavirus where I live, the likelihood that the person is COVID-positive is low—almost certainly less than 10 percent. And the likelihood of contracting the virus from a single pass-by with another person outside is also low—probably less than one in ten thousand (more a speculative guess than anything else). But I feel threatened with bodily harm by every such person—and these are the neighbors among whom I live.

Where else can this phenomenon be seen? One can certainly imagine this phenomenon happening when soldiers on counter-insurgency missions come across a village in which two hundred villagers are probably friendly or neutral (i.e., pose no threat) and one person may be carrying a grenade underneath a shirt. The likelihood that one person in the village would want to do those soldiers bodily harm is low, but it is not zero, and soldiers learn to regard everyone in the village as a potentially lethal threat. Usually, this does not lead to open uses of force, but the sense of threat, under those circumstances, cannot be eliminated—and they have to regard every person in the village as a potential threat until shown otherwise. That is, the default assumption must be that a villager is regarded as potentially threatening until evidence disproves that assumption.

Of course, the scenario above is no one-time event. As stressful as the scenario is, it is repeated many times over a tour of duty. These then are the multiple potentially traumatic events that the soldier perceives and experiences as a threat to safety—and what leads to the symptoms of operational stress. And soldiers in combat zones have usually deployed far from home, away from the social support that usually helps people to cope with mental and emotional stress. (So too is the case with public health guidelines calling for social distancing—hugs from friends and relatives not within my shelter-in-place pod are off-limits.)

I do not pretend for a moment that what I am experiencing in my walks around town carry in any way the same significance or risk as for the combat soldier. I have never been under actual fire, even though I have been a student of national security affairs for forty-plus years. But it appears to me that living through the pandemic has some of the features, in a much less intense way, of that combat experience—and perhaps it has given me a point of departure for understanding, in a very small way, what ground soldiers on patrol in Iraq or Afghanistan must experience every day.

Certain similarities are quite striking. Foreign territories occupied by force can be hostile towards ground soldiers, and threat lurks everywhere—and with the pandemic spread of disease, viral threats lurk everywhere. Soldiers on deployment are separated from friends and family back home—and because of social distancing imperatives, citizens do not have access to the usual social mechanisms of family, friendship, and companionship that moderate the effects of stress under non-pandemic circumstances. Detailed information about the ground situation needed by soldiers to cope with daily updates of intelligence briefings—and information about how to cope with Covid-19 seems to change daily. And the uncertainties of both intelligence briefings and news-for-the-citizen should not be surprising in a situation where both analysts and scientists are trying to make sensible statements about phenomena that are not well understood. These uncertainties greatly magnify the sense of anxiety that accompanies stress responses. 

One of the most important similarities lies in the future. Just as soldiers returning from combat must be reintegrated into society in a healthy way, the nation’s citizens will have to recover from having lived through a mentally stressful experience unprecedented in most of their lifetimes. How will affected citizens—even if they never contracted coronavirus—deal with the negative mental health effects the pandemic has induced.

The Department of Defense (DoD) and the Veterans’ Administration (VA) have substantial expertise in treating psychological stress disorders induced by combat. Combat conditions are much more objectively stressful than the conditions encountered every day by ordinary citizens (excluding health care workers), but it may be the case that DoD/VA expertise has some applicability to helping the nation’s citizenry at large recover from coronavirus-related psychological stresses.

Some of the important questions to explore include: 

• What are the important similarities and differences between combat stress for soldiers and coronavirus stress for the population at large?

• How and to what extent, if any, can DoD/VA expertise in treating combat and operational stress in soldiers be applied to the larger but less intense problem of treating coronavirus stress?

• Given that treatment of combat and operational stress is most often undertaken individually or in small groups, how might DoD/VA treatment techniques be scaled to help the population at large?

• What could be the role of automation and computer-based applications in scaling treatment?

Even if effective treatments and vaccines for coronavirus become available soon, it is not too soon to start thinking about the mental health dimensions of national recovery. The DoD and VA have what is likely to be the largest national repository of expertise in dealing with mental and emotional trauma induced by stresses in the environment, and the nation should be drawing on such expertise as it looks forward to a post-coronavirus world.

Dr. Herb Lin is Hank J. Holland Fellow in Cyber Policy and Security at the Hoover Institution and senior research scholar for cyber policy and security at the Center for International Security and Cooperation, both at Stanford University.