2. Merriam-Webster define stress as:
A physical, chemical or emotional factor that
causes bodily or mental tension
3. Acute stress is general short-term with a
clearly defined beginning and end
Chronic stress is long-term and prolonged
stress with no clear ending
Both acute and chronic stress trigger the
physiological stress response
4. Triggering of the sympathetic nervous system
which prepares the body to deal with
perceived threat by:
◦ Increase of heart rate and blood pressure
◦ Increase of cortisol – “stress” hormone which has
anti-inflammatory and immunosuppressive
properties
◦ Decline of parasympathetic activity which regulates
“automatic” bodily functions and maintains
homestasis
5.
6. ◦ Shorter form of
the serotonin
transporter is
associated with
vulnerability to
increased
response to
stress by
developing
depressive
illness and
alcoholism
7. ◦ An allele of the monoamine oxidase A gene result
in more vulnerability to abuse in childhood,
increased risk of becoming an abuser & show
antisocial behaviors.
8. Early abuse can result in life long emotional
reactivity and stress hormone reactivity –
both associated with cognitive decline and
shorter lifespan in animal studies
9. Stress reduction in infants can be influenced
by maternal bonding through a variety of
factors
◦ Physical proximity
◦ Modeling
Early patterns “hard-wire” the stress
response –critical period during 1st nine
months
10. Males most typically mirror the fight or flight
response
Females engage fight or flight AND befriend
11. There is an inverted relationship between
learning and levels of cortisol
During acute stress, higher levels of cortisol
result in:
◦ Enhanced immunity
◦ Enhanced memory
During chronic or prolonged stress,
the increased levels of cortisol result
in:
◦ lower immune response
◦ Impaired cognitive functioning
12. The Hippocampus is
the brain structure
primarily responsible
for learning and
memory
The Hippocampus is
highly sensitive and
malleable
Cortisol decreases
and retracts the
dendritic growth in
the hippocampal area
13. Within the Hippocampus, is the dentate gyrus,
a structure which seems to play a role in the
memory of sequences of events
It has high plasticity and is constantly
producing new neurons, even throughout
adult life.
Certain types of stress suppress neurogenesis
and cell survival in the dentate gyrus
14. Cortisol inhibits long-
term potentiation – cell
sensitivity in
communication
Adolescent brain is more
receptive to long-term
potentiation without
interference
15. Repeated or chronic stress causes dendritic
shortening in the medial prefrontal cortex
The results in impairment in attention set
shifting
16. Both acute and chronic stress produce
dendritic growth in neurons in the amygdala.
The results of include:
◦ Increases anxiety
◦ Increased aggression
17. In animal research, chronic stress causes
atrophy of neurons in the hippocampus and
prefrontal cortex
and
Hypertrophy of neurons in the amygdala
Results:
◦ Decreased learning and memory
◦ Increased anxiety and aggression
18. The results from
animal studies are
mirrored in humans
through a loss of
hippocampal volume
and an increase in
amygdala volume in
MRI studies
PET scans also
demonstrate altered
patterns of activity in
the related brain areas
during stress
19. Learn stress
management – variety
of techniques
Problem-focused –
changing the stressor
Emotion focused –
changes our response
to the stressor
25. Optimism is associated with lower cortisol
production and higher heart rate variability
(showing higher parasympathetic activity)
Optimistic people are, on average, healthier
and live longer than pessimistic people
Optimistic people have higher levels of life
satisfaction
26. Poor self-esteem has
debilitating effects:
◦ Increased levels of cortisol
◦ Inability to regulate cortisol
levels under stress
◦ 12-13% loss of hippocampal
volume
27. Improve sleep quality and quantity
Have a good social support system
Maintain a positive outlook on life
Maintain a healthy diet
Avoid smoking
Regularly exercise – moderate activity
Build positive self-esteem
Learn successful stress management
28. McEwen, B.S. Protective and damaging effects
of stress mediators: central role of the brain.
New England Journal of Medicine. 1998, 338:
171-179
29. Q&A
Robin Donaldson,
rdonaldson@nationalsafeplace.org
Notes de l'éditeur
Individual differences in stress response are genetically influenced
statistical correlation between violence and the levels of MAO assayed in blood platelets. Lower MAO activity is found in violent criminals, both male and female. The gene for monoamine oxidase A (MAO-A) is located on the X chromosome and individuals with deletions and point mutations are known. Thus MAO-A defects are sex-linked. Alterations in the MAO-A gene result in marked changes in monoamine metabolism and are associated with variable cognitive deficits and behavioral changes in both humans and transgenic mice. The incidence of severe MAO-A defects is extremely low, and unlikely to account for more than a tiny proportion of criminal behavior. On the other hand, it is conceivable that the wider correlation between MAO levels and violent crime is due to genetic alterations that result in moderate reduction of monoamine oxidase activity.
Individual differences in stress responses also appear to be related to maternal care and early attachment
An important factor in all healthy coping skills is the idea of control
Researchers have studied the “belief hormonal response” triggered even with placebos and discovered that “belief” turns on endorphins
