madeleines and the writers who write about them.
At its root, PTSD is a memory disorder. Brain scans of people
suffering PTSD show cellular and volume changes in the
hippocampus, a region that helps process memories and sits very
close to the amygdala. In frightened lab animals, the fear hormones—
glucocorticoids like cortisol, norepinephrine or adrenaline—flood
receptors on the hippocampus and impair memory. It appears that
persistent trauma memories shrink the hippocampus, and it’s well
established that PTSD leads to emotional as well as cognitive
problems, such as poor focus and short-term memory deficits.
Physiologically, chronic, heightened stress looks like this: higher
blood pressure, cellular inflammation, and a higher risk for cardiac
disease. Longitudinal studies show that veterans with PTSD are
sicker, in more pain, and die younger than their non-PTSD peers.
They are also 4.5 times more likely to have substance abuse issues.
Veterans are twice as likely to be divorced, and female veterans
commit suicide at nearly six times the rate of other women.
Groups like Higher Ground—and there are many, from those
offering surfing and fly-fishing programs for vets to a hospital in Los
Angeles that promotes bonding between humans and abused parrots
with symptoms resembling PTSD—believe that engaging with nature
or wildlife can reduce trauma symptoms. Adventure sports like
kayaking provide a laser focus for an unfocused mind, as well as a
welcome distraction from unwelcome thoughts. The physical exertion
often leads to better sleep, and, as we’ve seen in previous chapters,
the sensory elements of nature can calm the nervous system.
Even knowing all this, I couldn’t help but worry a bit about these
women in such an uncontrolled environment. What if they got pinned
on a rock or had a bad swim? One of the kayakers was Marsha
Anderson, who’d been a ski racer in her youth in Wyoming. Now she
had nerve damage in an arm and a leg from an explosion in
Afghanistan in 2009, and she hurt all the time. After her injury, she