The Effects of Stress on Our Brain and BodyMonday, 12 June 2017 00:00 Written by Super User
Guest blog written for ATS by Robert Avsec
Much is being written about and talked about regarding post-traumatic stress and its effect on firefighters. The job has always been physically and emotionally taxing, but an increasing awareness of the adverse effects of post-traumatic stress is "shining a light" on the difficulties that many firefighters have coping with those stresses. From behavioral changes to alcohol and substance abuse to suicide, too many firefighters are unable to cope with those pressures.
How our brain handles stress
Figure 1. Source: Your Brain on Stress and Anxiety. https://vimeo.com/78895649
The amygdala or "reptilian brain" is where the body's "fight, flight or freeze" response capacity is located. The hippocampus or "emotional brain" is where we get our ability to feel emotions, have a sense of our environment, aka, the world we live in. The prefrontal cortex or "executive brain" is where we process daily events and attempt to "find meaning for everything" 
In a firefighter's world, the amygdala remains engaged more than it does in the general population. The mere fact of being in a fire station and on-duty and ready to respond at a moment's notice to an unknown event, serves to "keep the motor running." When the alarm comes in, the amygdala unleashes a chemical wave of hormones to prepare the body for a perceived "threat":
Figure 2. Source: Rebecca Rengo. The Stress Response System. http://rebeccarengo.com/the-stress-response/
In this case, the threat at this point is emotional, not physical. The brain, however, doesn't differentiate between the two in its response .
The brain's #1 job is to keep you physically and emotionally safe and secure. To do that it's imperative that each section of the brain carries out the functions it is most capable of doing. Nature did not design the amygdala to do all the work—its sole purpose is primarily to "save" us from threats .
Figure 3. Source: http://richardshealthmusings.com/stress-is-it-friend-or-foe/
Over time, as the amygdala continues to be regularly engaged it enlarges (hypertrophy) and the hippocampus and frontal cortex both begin to diminish (hypotrophy). Eventually, the amygdala also begins to suffer hypotrophy .
These physiological changes in the brain are what contribute to a reduction in an individual's resilience, their capacity to respond and recover from stress. This breakdown of an individual's resilience is both physical and emotional due to the body constantly be awash in those hormones being released on the command of the amyhdala.
Figure 4. Source: Brain Matters March 5 In-service. https://www.slideshare.net/anoonen/brain-matters-march-5-inservice
In Figure 4 above, we see some of the manifestations of stress on these three key centers of the brain (the red box). As the amygdala stays "ramped up", we see everything "speeding up": Anxiety level, fear, neuron activity, and the depletion of dopamine. Dopamine is a key drug for maintaining proper brain function:
Dopamine is a neurotransmitter that helps control the brain's reward and pleasure centers. Dopamine also helps regulate movement and emotional responses, and it enables us not only to see rewards, but to take action to move toward them. Dopamine deficiency results in Parkinson's Disease, and people with low dopamine activity may be more prone to addiction. The presence of a certain kind of dopamine receptor is also associated with sensation-seeking people, more commonly known as "risk takers" .
Let's highlight one sentence from above, "Dopamine deficiency results in Parkinson's Disease, and people with low dopamine activity may be more prone to addiction." When the amygdala is constantly engaged—responding to physical and emotional stress—and dopamine production decreases this may be a significant factor in an individual "self-medicating" with alcohol or drugs in an effort to deal with the effects of on-the-job stress .
Effects of Stress on Decision-Making
During heightened periods of stress, stress your prefrontal cortex, where decision-making, rational thought, and reasoning occur, is temporarily shut down while your amygdala takes over (engaging your "fight, flight, or freeze" response). But since your prefrontal cortex is where your instinct and training reside, stress can basically make you dumb, or at least make bad choices. This is what the effects of stress on the brain can "look like":
Table 1. Source: Richard's Health Musings. Stress: Is it Friend or Foe? http://richardshealthmusings.com/stress-is-it-friend-or-foe/
Effects of Stress on the Body
The chemical wave unleased by the amygdala doesn't only have an effect on the brain. There are manifestations throughout the human body as shown in Figure 5 below.
Figure 5. Source: Stress: Is it Friend or Foe? http://richardshealthmusings.com/stress-is-it-friend-or-foe/
According to the Centers for Disease Control and Prevention, up to 90 per cent of all illness and disease is stress-related. Give that a minute to sink in. Because stress effects so many areas of the body, if you are living with constant stress it is possible your body is deteriorating day by day. Some signs of this negative impact of stress on the body include, but are not limited to, the following:
• Skin irritations
• Frequent infections
• Tight muscles
• Muscle twitches
In our next article, we'll discuss some of the more current strategies for coping with stress and its effect on both the mind and the body.
1. Hill, A. Presentation to Warrior Heart Honorary Board of Advisors. March 31, 2017. Bandaras, TX.
4. Richard's Health Musings. Stress: Is it Friend or Foe? [Available on-line] http://richardshealthmusings.com/stress-is-it-friend-or-foe/
5. Psychology Today. Dopamine. [Available on-line] https://www.psychologytoday.com/basics/dopamine
6. 1. Hill, A. Presentation to Warrior Heart Honorary Board of Advisors. March 31, 2017. Bandaras, TX.
7. Richard's Health Musings. Stress: Is it Friend or Foe? [Available on-line] http://richardshealthmusings.com/stress-is-it-friend-or-foe/
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Battalion Chief Robert Avsec (Ret.) served with the Chesterfield (Va.) Fire & EMS Department for 26 years. He was an active instructor for fire, EMS, and hazardous materials courses at the local, state, and federal levels, which included more than 10 years with the National Fire Academy. Chief Avsec earned his bachelor of science degree from the University of Cincinnati and his master of science degree in executive fire service leadership from Grand Canyon University. He is a 2001 graduate of the National Fire Academy's Executive Fire Officer Program. Since his retirement in 2007, he has continued to be a life-long learner working in both the private and public sectors to further develop his "management sciences mechanic" credentials. He makes his home near Charleston, W.Va.