22 February 2020 | New Scientist | 35damaging to our well-being that one in three of
these people had been left feeling suicidal, and
one in six had self-harmed.
Yet, stress is also an essential physiological
response that allows us to quickly adapt to
the world around us. What we call stress is
actually a chemical reaction that begins in our
brain, specifically the amygdala, which is on
constant surveillance for any potential threat.
The amygdala combines sensory information
with memories of similar situations to judge
whether an emergency response is required.
If alarm bells ring, a distress signal is sent to
the hypothalamus – a small nodule near the
base of the brain – which activates two
major pathways. The first triggers our ancient
fight-or-flight system, which pumps out
adrenaline, making us more alert by increasing
our heartbeat and the efficiency of our
breathing and forcing more blood into our
muscles. The second prompts the release
of other hormones, including cortisol. This
keeps the stress response active and releases
stored glucose to give us more energy. It
also suppresses our digestion, immune system
and inflammation, to focus resources on the
immediate threat. When the threat has passed,
cortisol levels drop, helping to bring all these
chemicals back to their original levels.Runaway response
This is all very handy when you are facing a
poisonous snake or an oncoming vehicle
because it enables you to start taking evasive
action before you have even registered the
threat. It also allows you to concentrate on
your work as a deadline looms, and focuses
your thoughts when speaking in front of an
audience. But sometimes the stress response
kicks in unnecessarily or is so powerful it
overwhelms us. Sudden or severe stress can
result in PTSD and depression. And low-level,
chronic stress creates a slew of health
problems. With no let up, raised levels of
adrenaline can damage blood vessels and
increase the risk of heart attack and stroke.
Cortisol can cause digestive problems,
weight gain and diabetes. And constant
modulation of the immune system can lead to
fatigue and physical and mental health issues.
Whether stress has positive or negative
consequences often depends on how we
deal with it. Your reaction to stress and how
quickly you return to normal when the
stressor has passed is called resilience.
This is what varies significantly between
individuals. But what makes some of us so
resilient while others struggle to cope?Y
OU know that person. The one who
uses a delayed train as an excuse to get
stuck into a good book. The one who can
make a joke 10 seconds after breaking their
ankle. The one who loves giving presentations
and never falters under pressure. They seem to
float through life unfazed by the stress that can
overwhelm the rest of us. What’s their secret?
Are they blessed with stress-resistant genes?
Did their upbringing make them exceptionally
resilient? Have they learned specific ways
of coping with life’s challenges? Or do they
just know how to avoid stress altogether?
To answer these questions, researchers have
been examining how humans and animals
react and adapt to adversity, identifying those
who are particularly resilient to stress and
teasing apart the factors that contribute to this
ability. It is a journey that has taken them from
orphanages in Romania and interrogation
chambers in North Carolina to fire stations in
Indianapolis and humour classes in Austria.
This work is helping the military recruit
candidates for high-stress jobs. It has also led
to the first human trial of a “stress vaccine”,
with the potential to inoculate us against its
devastating effects, from post-traumatic stress
disorder (PTSD) to depression. But there is
a bigger pay-off to understanding the secret
of stress-free living. Knowing why some
people handle stress better than others, and
the things we might all do to improve our
resilience, won’t just help all of us manage life’s
daily struggles better, it might also teach us
how to use stress to our advantage.
One thing is for certain: whether you are
running late for an interview or coping with a
personal loss, stress is unavoidable. In 2018, the
largest known study of stress levels in the UK
showed that three-quarters of people had been
so stressed in the past year that they had felt
overwhelmed or unable to cope. It can be so >