B0038M1ADS EBOK (14 page)

HM3 J and SSgt L were experiencing reactions common during the
transition period after returning home from deployment. Medical professionals may label reactions such as startling easily, sleep disturbance,
anger, being hyperalert, and avoidance of going out as symptoms of PTSD
if they interfere with work or relationships. However, these postwar reactions can also be considered normal. It's not always clear where to draw
the line between normal and abnormal.

How the Brain Reacts to Threat

Extensive research has characterized the neural (brain) processes involved
in responses to high threat or danger. The "limbic system," the part of the
brain that acts as the alarm signal for the fight-or-flight reflex, consists of
neuronal pathways deep inside the brain (beneath the rational cerebral
cortex) that connect to the brain areas responsible for various physiological functions of the body, including heart rate, blood pressure, circulation, breathing, and hormone balance (e.g., adrenaline and the stress
hormone, cortisol). The limbic system takes over whenever there is high
threat, ensuring that the body responds rapidly. This system is critical for
ensuring that the body's reflexes will kick in when needed. The limbic
neurons trigger the release of adrenaline through the "autonomic" nervous system-the system of nerves that control unconscious physical processes in the body, including breathing and heart rate. Adrenaline tenses
muscles; increases alertness, attention, heart rate, and blood pressure; and
changes the way a person scans the environment for threats. The limbic neurons also cause the release of stress hormones, which increase endurance, as well as chemicals, similar to morphine, that dull awareness of
pain. The limbic alarm system of the brain "hijacks" the conscious rational
areas in order to ensure that the person's entire attention and focus is
directed toward survival.

The primary emotion of the limbic system is anger. Fear is also present, but warriors learn to control this by falling back on their training.
Anger helps to control fear. Emotions other than anger are generally shut
down. While the speed of processing information increases, the ability to
be self-reflective or consider things in a rational sequence diminishes. In
times of danger, a moment of reflection may make the difference between
life and death.

As an example of how the limbic system works, imagine walking
through a forest and encountering a snake just where you're going to step.
You instantly jerk your foot away to avoid stepping on it and save yourself
from being bitten. You do this without thinking. Only after this reflex has
kicked in do you notice that there was no snake in your path after all; it was
just a vine shaped like a snake. You may feel like an idiot for overreacting
to a vine, and your friends may laugh, but the bottom line is that you had
no control over your reflex. Your body did what it needed to protect you.
If there really had been a snake, you'd be very happy to have this reflex.
The reflexes honed during military training and combat are some of the
strongest reflexes that a person can ever develop-reflexes that become a
way of life for a warrior.

The limbic alarm system is regulated by another part of the brain
called the medial prefrontal cortex. The medial prefrontal cortex is front and
center, literally and figuratively. It's located in the front part of the brain
inside the midline groove separating the right from the left sides. It's an
important part of the cerebral cortex that connects with the deeper limbic
neurons involved in the fight-or-flight reflex. One of the most important
jobs of the medial prefrontal cortex is to provide control over the limbic
area. This part of the brain is what allowed SSgt L to accept the advice of
Sally's sister and cool down outside rather than make things worse. This
part dampens or controls the fight-or-flight reflex and tries to keep it from indiscriminately firing when there is no real threat. The medial prefrontal cortex is critical in planning, decision-making, and thinking through
actions. It's important for anticipating what you're going to do next and
thinking through the sequence of things.

In summary, the limbic system ensures that you can react immediately
to threat, and the medial prefrontal cortex helps to keep this in balance.

The problem for combat veterans is that the medial prefrontal cortex,
the part of the brain that helps to balance out the protective reflexes, may
not work well when there is sleep deprivation, high-intensity combat, or
other very stressful experiences. Brain-imaging studies show reduced functioning in this part of the brain as a result of both extreme stress and sleep
deprivation. This means less control of the limbic system, which means
you're more likely to overreact with anger or other fight-or-flight responses
to situations that aren't particularly dangerous. Reduced prefrontal brain
functioning as a result of combat experiences and sleep deprivation is a
common reason why veterans complain of poor concentration, memory
problems, cognitive dysfunction, and bad decision-making after returning
from deployment.

Sleep Deprivation

During continuous military operations, it's not uncommon for warriors to
go for extended periods with reduced sleep. Traditionally, military leaders
have considered four hours' sleep an acceptable level in the war zone, and
indeed, warriors can learn to adjust to this amount of sleep (sometimes
catching micro naps to compensate). Over time the cumulative loss of
sleep takes a toll on the ability to think clearly, and makes it difficult to
sleep restfully after returning home. The problem isn't only the limited
amount of sleep, but also the fact that most operations in the war zone
happen at night. Trying to catch up on sleep during the day doesn't match
with the human biological clock, known as the circadian cycle, a complex
process in the brain that's regulated by daylight and involves secretion of
the sleep hormone melatonin at night and suppression of this hormone
during the day. Melatonin helps to bring on sleep and make it restful,
which is one reason why nighttime sleep is more restful than the same amount of sleep during the day. After learning to function on less sleep
and repeated night shifts, it may be very difficult to retrain the body and
return to a normal cycle of sleeping throughout the night. Sleep deprivation, as well as combat stress, trauma, and high immediate threat to life,
can all impair the medial prefrontal cortex of the brain, which then causes
the limbic system to take over and rational thinking to be diminished. The
medial prefrontal cortex is a part of the brain particularly susceptible to
dysfunction after trauma and sleep deprivation.

Five to six nights with only four hours of sleep each night has been
shown to have the same effect on cognitive ability as a full night of no
sleep or a blood alcohol level of 0.1 percent-legally drunk. After this
level of sleep deprivation, a person doesn't have coordination problems and can still walk a straight line; however, their ability to think is
impaired. There is also a vicious cycle that veterans can fall into: Sleep
deprivation reduces the ability of the medial prefrontal cortex to keep
the limbic system under control. This can lead to feeling irritable and
revved up, which in turn causes the medial prefrontal cortex to not function well, making things even worse. Many veterans feel like they live
constantly in a state of either fight or flight, with little rest in between.
Rational thought and reason get compromised.

Studies have shown that sleep deprivation significantly increases levels
of anger, impulsivity, and aggression, as well as quicker and more forceful reactions to any provocation. The ability to be self-reflective and consider options is decreased, which causes decision-making to be impaired.
There is increased risk-taking, decreased empathy, and decreased consideration of the long-term consequences of actions. There are also important misperceptions of thinking, termed cognitive distortions, which result in
perceiving things as more threatening than they really are.

A Vicious Cycle of Prolonged Stress

For HM3 J, his body wasn't able to decompress, meaning that he stayed
revved up and reactive to loud noises and crowds. As a result, he drank more
alcohol. Although this seemed to help him calm down, it actually made
things worse. Alcohol affects the quality of sleep, and it's very common after drinking to experience very poor sleep or wake up in the middle of the
night or early morning and not be able to get back to sleep. The increased
use of alcohol and increased anger resulted in HM3 J being caught in a
vicious cycle of worsening sleep, increasing withdrawal from everyone, and
being angrier at himself-a pathway toward depression and PTSD.

In SSgt L's situation, when he mixed up his directions while driving,
he didn't have the ability to stop what he was doing, consider the options
(other than calling his fiancee), and avoid getting angry. His body was
flooded with a sudden adrenaline surge, and he became hyperalert to
threat, using all the skills he had used during deployment. He expected
his fiancee to be available, and when she wasn't, he reacted with rage. All
of this was also compounded by sleep deprivation.

Working in a combat zone, combined with sleep deprivation, results
in a number of physical changes in the body. During times of stress and
danger, the body is revved up due to adrenaline and other chemicals; the
heart rate is increased, breathing becomes more rapid and shallow, muscle tension increases, and the mind becomes hyperalert. As a result, warriors are able to maintain high situational awareness, which is a very useful
skill. This includes scanning the environment for anything that might be
a threat, using their own fear or anxiety as a warning signal, and ensuring that there are always escape routes. All of this involves activation of
stress hormones. However, if the warrior is unable to decompress after
deployment, or develops PTSD, this sustained level of stress can progress
to hypertension (high blood pressure) and cardiovascular problems. The
increased adrenaline and stress hormone levels also affect the digestive
system-stomach and intestines-causing them to slow down, which can
lead to gastroesophageal reflux disease (GERD), stomach ulcers, and feelings of queasiness or nausea. Prolonged stress can also affect the immune
system, as well as sexual function.

Anger

The prominent emotion of prolonged stress for warriors during combat is
anger. The other common emotional condition is feeling no emotion at
all, or, in warrior's terms, "emotional control." Emotional control, through numbing or detachment, is necessary under extreme stress. In combat, a
warrior learns to turn off emotions other than anger. Anger/rage is the
"fight" part of the fight-or-flight reflex, which helps the warrior neutralize
the enemy. Anger masks other emotions, such as fear or sadness, allowing
the warrior to do what needs to be done under fire. Even if a unit loses a
team member, right after the casualty is removed or the memorial service
is finished, the grief has to be put on hold when the unit goes back "outside the wire." The warrior learns to control anger itself through training,
so that anger doesn't completely take over and impair the mission. Buddies help with this, and seasoned combat warriors learn how to monitor
each other. After coming out of a combat environment, it can take a long
time before a warrior can express a full range of emotions again.

Cognitive Problems

Warriors often complain of having difficulty concentrating or problems
with memory, attention, or thinking after leaving the war zone. These
cognitive problems are some of the most common complaints of veterans after returning from war. Warriors also complain about having a hard
time concentrating and maintaining focus on one task. On a neurological
and physiological level, these problems are due to chronically elevated
adrenaline and stress hormone levels associated with overactivation of the
limbic system and reduced functioning of the medial prefrontal cortex
of the brain. However, of more immediate concern, these cognitive difficulties result from essential survival skills related to the ability of a warrior to maintain control under fire. Memory, attention, and concentration
all become oriented toward survival, and this can make it difficult to stay
focused on other things after returning home.

Control

Control is an essential survival skill. Survival in the combat zone depends
on the ability to react instantaneously with the correct sequence of combat
tasks under fire. You depend on your equipment, your training, and your
buddies, and if any one of these fails, then the mission can fail. The key
is having all your equipment in the best working order exactly where you need it, doing exactly what is required under fire based on your training,
and relying on your buddies to do exactly what is required of them. A warrior lives and breathes what they're required to do, and a good unit leader
will continuously train the unit to ensure that each team can execute combat tasks collectively without hesitation. The success of the mission and the
ability to respond on enemy contact in a flexible and effective way requires
that everyone on the team perform their tasks instantly and in the correct
way, according to their training and experience. This starts with memorizing common tasks, which after intensive training become reflexive actions.
This is how the warrior maintains control under fire.

However, after returning home, the warrior continues to utilize all
of these skills, including high situational awareness, scanning for threats,
monitoring escape routes, controlling emotions, and keeping thought
processes focused on survival, both for himself and others. This can result
in the warrior experiencing difficulty tolerating someone moving their
things unexpectedly, or difficulty with loved ones, friends, coworkers,
or anyone not following through with what they say they're going to do.
When the warrior gets stressed, which is common in daily life, his body can
suddenly feel like it's back in the war zone.