Stress: the brain, body and performance
PS3002: Brain & Cognition
John Beech
School of Psychology
University of Leicester
1
Stress: the brain, body and performance
Introduction:
Types of stress:
1. Physiological – The SAM & HPA systems, the GAS syndrome
(Selye), effects on health, especially immunity.
2. Performance
(a) Cognitive – Yerkes-Dodson, effects on memory &
concentration.
(b) Behavioural – Absenteeism, sleep disorders
3. Emotional – physical tension, anxiety & depression
Interventions
1. Transactional stress-coping
2. Stress inoculation
3. Biofeedback
4. Social Support
5. Drugs
2
Defining stress
Stress is hard to define because it depends on the situation. Hans
Selye* (1956) suggested that stress was the rate of wear and
tear caused by life, implying that if you have a lot of stress for a
long period, your body will reflect the consequences.
Individuals vary in their responses to stress, so the extent to
which that individual’s body reacts to stress could be
considered to be what stress means to that particular person.
There are different types of effects of stress as follows…
[*pronounced Sell-yay]
3
Introduction: the effects of stress
1. Physiological effects –
•
•
•
•
•
•
the body responds:
Adrenaline & noradrenaline
released
Digestive system closes – stomach
feels queasy
Air passages in lungs expand –
respiration increases
Heart rate increases
Blood vessels constrict
Pupil dilation
2. Effects in Performance
(a) Behavioural effects
– Absenteeism increases and
work performance reduced
– Sleep disruptions
(b) Cognitive
– Easily distracted/poor
concentration
– Reduced STM capability
3. Emotional
•
•
•
Increasing psychological tension
Anxiety & depression
Increasing physical tension –
muscles ache
4
Stress: physiological effects
• Satcher (1999) “We know that 50%
of deaths are directly related to
human behaviours, and yet we
spend too little time doing research
and implementing programs related
to them” (the US Surgeon
General).
• We need to understand how our
bodies respond to stress, starting
first by looking at what happens
when we respond to danger.
5
The activation of two systems: SAM and
HPA**
Stressor  hypothalamus
Immediate effect
Activates SAM – the Sympathetic Adrenal
Medullary system. Activity in the
sympathetic part of the ANS stimulates
the adrenal medullary system*
Longer term effect (hours +): HPA**
SAM consumes resources – so
countershock to reduce damage
The hypothalamus produces corticotropinreleasing factor (CRF)
Activates anterior pituitary gland
Produces adrenaline & noradrenaline
Arouses the sympathetic branch of the ANS
& reduces activity in the
parasympathetic system.
Releases ACTH*** – stimulating the adrenal
cortex producing cortisol
Gives steady supply of glucose and
suppresses the immune system
(*part of adrenal glands)
(**hypothalamic-pituitary-adrenocortical
axis;*** ACTH = corticotropin)
6
The physiologist Walter Cannon
(1929) first suggested the term
‘flight or fight’ for our reactions
to stress.
He proposed the thalamus was the
important part that
simultaneously caused both
emotional and physiological
responses. But now the
thalamus is not considered to
be particularly important.
He also noted that these effects are
irrespective of the type of threat
(e.g. fear, trauma, a bad
incident, etc.)
Effects of stress on
health
7
Effects of stress on health
General Adaptation
Syndrome (GAS) – Hans
Selye (1907-1982)
Selye was an Hungarian-born
Canadian. He proposed 3
stages of GAS:
1. Alarm reaction – the body
prepares for ‘flight or fight’ –
this is not a sustainable
condition. The sympathetic
nervous system is increased
leading to the release of
hormones from the adrenal
gland. We have all the
physiological responses we
mentioned (e.g. to pulse
rate, breathing etc). (Like
the SAM system.)
8
Effects of stress on health
General Adaptation
Syndrome (GAS) –
Hans Selye
2. Stage of resistance
Signs of strain emerge and
we experience
increasing psychological
disorganisation. Coping
mechanisms are
intensified. But if the
stress is long-lived we
resort to inappropriate
coping techniques –
probably too rigidly. This
depletes emotional
resources further. Signs
of wear and tear appear.
This stage is known as
adaptation, and as
already described, leads
to elevated levels of
homeostasis*.
*(homeostasis = maintenance of
equilibrium by adjusting
physiological processes)
9
Effects of stress on health
General Adaptation
Syndrome (GAS) –
Hans Selye
3. Stage of exhaustion
We continue to use defence
mechanisms that are
getting more ineffective.
Some lose reality. Others
have ‘burnout’ – inability
to concentrate, delay,
irritability, nothing
worthwhile. Can turn to
alcohol, drugs, get skin
or stomach problems. If
this continues may
produce irreparable
damage.
10
Effects of stress on health - GAS
• If this third stage keeps going then this produces
‘accommodation’. Biologically this means that the
response of a biological object in the face of a constant
stimulus decreases over time. For example, the athlete’s
training for a sustained period eventually leads to a plateau
in performance. To avoid this the athlete needs to vary
training and also take some rest.
• This is a multileveled model. If there is rest from the
stimulus (the stressful experience) can allow adaptation.
This can be viewed positively if the graph is thought as a
training schedule in which the body is being physically
trained, but not so good (or even disastrous) if it is seen as
physiological responses to continuing stress.
11
Effects of stress on health - GAS
• Cortisol helps the body to come to terms with stress
during this phase. In more extreme cases of stress,
glucocorticoids are produced attempting to restore
homeostasis, but this also depresses the immune
system. (Glucocorticoids also have antiinflammatory properties.)
• Selye proposed a ‘hypothalamic-pituitary’ axis as
the key brain system and now this is referred to as
the LHPA – ‘Limbic-hypothalamic-pituitary axis’ by
many although Michael Eysenck refers to the
hypothalamic pituitary-adrenocortical axis (HPA) .
• So how can physical stress lead to health
problems?...
12
Effects of stress on health - GAS
The effects
• Stress makes the heart, lungs, nervous system and
other systems work harder. But prolonged exposure to
these systems can lead eventually to physical
disorders.
• Stress powerfully affects the immune system and
sustained stress can destroy this capability to protect
against disease. The coping behaviours of smoking,
alcohol use, overeating, not exercising further reduces
healthiness.
The evidence
There is mounting evidence for the effects on both the
brain and the body, so we will only sample some:
Cortisol (mentioned as active in the exhaustion stage) can
damage hippocampal cells and therefore affect learning
and memory (Newcomer et al. 1999; Sapolsky, 1992).
13
Effects of stress on health
The evidence for stress affecting health
(continued)
Cortisol also increases blood pressure, which weakens
the walls of blood vessels, can trigger erratic heart
beats, increase cholesterol (leading over time to
hardening of the arteries). Life stresses and social
isolation have been shown to predict subsequent
heart attacks (Ruberman et al. 1984).
The well-known ‘Type A’ personality has been shown
in several studies to predict coronary heart disease
(CHD). This type reacts with impatience, hostility to
events and is always striving. Similarly, people who
scored high on an anger scale were 2.5 times more
likely to have a heart attack (Williams et al, 2000)
But others have suggested that it is more lifestyle
(e.g. more smoking and drinking) that is important.
14
Effects of stress on health
The evidence for stress affecting health
(continued)
Bosch et al. 2001 showed how stress affected
immunity by looking at the concentration of
immunoglobins in the saliva. These are the first
line of defence that pathogens* have to cross.
They found that undergoing a timed memory task
activated this factor (increased immunity)
whereas watching a violent video weakened
immunity. So stress can have differing effects
on immunity.
(*= agents causing disease, especially bacteria.)
15
Effects of stress on health
The evidence for stress affecting
health (continued)
Even chronic low-level noise from local
traffic can potentially affect health.
Evans & Lepore, 1993 found that such
noise increased levels of stress
hormone cortisol in children (total N =
115), including slightly higher blood
pressure and raised heart rate. The
symptoms included anxiety and
nervousness. Half the children lived in
quiet areas in Austria (< 50 dB – e.g.
quiet office) and half in noisier area
(>60 dB e.g. raised voices). So
exposure to the sounds from roads
and trains can be a stressor.
16
Effects of stress on health
The evidence for stress affecting health (continued)
The effects of negativity
Peterson, Seligman & Valiant (1988) found that pessimistic men were
twice as likely to have chronic disease than their optimistic Harvard
classmates 20 years later.
Barefoot et al. (1983) found that hostility predicted heart disease and
overall mortality over 25 years.
Depression (producing long-term stress) also increases the risk of
heart disease (e.g. McCabe et al. 2000).
However, these effects are not necessarily so stark, Booth-Kewley and
Friedman (1987) in a meta-analysis found only a low correlation of
0.14 between anxiety and heart disease. Other studies have found
no association in the long term between negative affect and overall
mortality (e.g. Shekelle et al., 1981).
17
Effects of stress on health - the field of
psychoneuroimmunology (PNI)
This field examines the
interaction
between stress
versus nervous
system activity,
the immune
system and the
endocrine system.
In a later study (Cohen,
2003) it was shown
that those who’d had
a lot of positive
emotions
(relaxation,
happiness) were
less likely to get
colds.
The association between psychological stress (low =
below median and high = above median) and
symptoms of upper respiratory illness among
subjects infected with an influenza A virus. Viral
inoculation occurred at the end of day 0. SEs are
indicated.
(Cohen et al.1999 – PSS = 10-item Perceived
Stress Scale, Cohen et al 1983)
18
Effects of stress on health: the
evidence (continued)
There are many such studies, including ones already
described. An important aspect of the immune system is
two classes of white blood cells: B cells (which mature in
the bone marrow) and T cells (which mature in the thymus
– located behind the top of the breastbone/lower part of
neck).
The natural killer (NK) cell is important for detecting and
destroying precancerous cells. So if certain types of white
blood cells are killed by a stress response then infection
and tumour growth may be stimulated. So many studies
look at the number of NK cells in the blood as an index of
the immune system. Glucocorticoids released during
stress hinder the formation of white blood cells such as the
NK cells.
19
Stress and
performance
•
•
•
Researchers have often
used arousal theory as a
means of explaining stress
on performance.
In particular the YerkesDodson law has been
prominent. This suggests
that we operate best at
moderate levels of
arousal. Increasing our
arousal beyond this leads
to reduced performance.
•
An increase in stress level
by an agent (e.g. noise,
•
drugs) results in the curve
shifting to the right. This
shift may not necessarily
•
be stressful, e.g.
incentives might be used.
The Yerkes-Dodson Law was originally used in the
context of motivation (‘drive’).
Duffy(1962) proposed increasing electrocortical
states, from left to right with lowest activity in the left:
delta
theta
alpha
beta
But there have been problems in reliably showing
this by psychophysiological techniques.
20
Stress and
performance
Wilkinson (1963) provided data
relevant to the Yerkes-Dodson
hypothesis looking at the effects
of noise and sleep deprivation.
The numbers in the cells of the
table illustrate increasing levels
of arousal. So the condition of
lowest arousal (1 in the table)
would be being sleep deprived
and carrying out an experiment
without any noise. Whereas the
highest level (4) would be
people who’d had normal sleep
and who had experienced
noise.
The task was a continuous reaction
time task and accuracy of
performance was monitored.
Quiet
(low)
Noise
(higher)
Sleep
deprived
(low)
1
2
Normal
sleep
(higher)
3
4
21
22
Stress and performance
•
•
•
The results showed an inverted-U
effect with the 3rd condition (those
with nomal sleep and quiet
conditions) producing the highest
accuracy on the experimental task.
Easterbrook (1959) explained the YD law by suggesting an analogy with
an internal searchlight for the focus
of attention that narrows as arousal
goes up. This results in the
attended stimuli continuing to be
processed optimally, but irrelevant
stimuli to be rejected.
But with further increases in arousal
the focus become too narrow and
even the performance with the
attended stimuli suffers.
•
•
•
In this hypothesis, with increased
task difficulty we need a widened
focus of attention (compared to
easier tasks), but unfortunately the
focus actually narrows, leading to
poorer performance at a lower level
of arousal.
A lot of experiments generally show
that changing arousal does
influence attention between primary
and secondary sources.
There are issues: (e.g. Eysenck,
1982) (1) is this process automatic
or voluntary? and (2) it probably
can’t apply to more complex tasks,
such as when attention and memory
interact. The Y-D concept has come
under a lot of criticism overall.
23
Stress and performance
Criticisms of Yerkes-Dodson
1. Problems of measurement. There have been unsuccessful
attempts to relate arousal to measures such as pulse rate and skin
conductance, but these don’t correlate with each other. So there
appears to be no successful measurement as yet. Similarly, there
is a lack of relationship between anxiety scales and
psychophysiological measures as a means of measuring arousal.
2. There could be several arousal systems. E.g. There could be
different arousal systems for nicotine and amphetamine, which
each affect different neurotransmitter systems. There is no
consensus on how these interact.
3. Lack of consistency. When individuals are in conditions of
extreme arousal the effects are weaker than might be expected.
24
Stress and performance
Effects of stress on memory
Bremner et al. (1993) compared Vietnam veterans who had combatrelated posttraumatic stress disorder (PTSD) with matched controls and
found that the veterans had problems with immediate and delayed
recall of verbal information, but there was no difference in IQ.
In severe cases an emotional shock can cause amnesia. Treatment
initially for a traumatic event can be sedation and plenty of care. Cases
are occasionally reported in the news.
This is known as dissociative amnesia in which there is a loss of
substantial important personal information, perhaps on more than one
occasion. This is usually traumatic in origin and so can’t just be
explained by forgetting.
A rare instance of this is when an individual suddenly leaves their home
and sets off on a journey that can last hours, days or even months.
They can be confused about who they are. Related to this can be
anxiety disorders and PTSD.
Treatments – therapy is designed to restore lost memory ASAP. Hypnosis
or medication can sometimes be useful in recalling identity.
Psychotherapy would help the individual cope with the underlying
trauma.
25
Cases of
amnesia
May 16th 2005 – this appeared in the press. The mysterious “piano man”
was found wandering on the Isle of Sheppey. On the right is his sketch
he gave to hospital staff. He subsequently played melancholic music
on a piano after it was provided for several weeks – without uttering a
word. By August he was flown back to his native Germany – but there
is speculation now that it was an elaborate hoax!
Agatha Christie is a famous example when she disappeared to a hotel in
Halifax in 1926 and afterwards she said that she’d suffered amnesia.
She had checked in under the name of her husband’s mistress.
26
Cases of
amnesia
On July 3, 2003 Doug Bruce walked into a police station saying that he
didn’t know who he was. Eventually, through contact with family and
friends he found out his identity. But so far, he remembers nothing of
his past. This was featured in 2006 in a TV documentary “Unknown
White Male”.
In his case his episodic memory appears to have been wiped out, and a
lot of his semantic memory, but his procedural memory seems
relatively unaffected. For instance, he could sign his name, but it was
not legible apart from the beginning “d”. He could speak English and
French. Was it induced by stress? Possibly.
It is likely that his memory will eventually recover.
A question still remains whether this too could be a hoax case.
27
Stress and performance
Effects of stress on memory (continued)
Why should stress affect memory? In the more extreme cases there is an
over-production of cortisol, secreted by the adrenal glands. This may
prevent the establishment of new memories as well as impairing
retrieval of what is in memory.
Sapolsky (1992) has suggested that this sustained production of cortisol
actually damages the hippocampus. Cortisol stays in the system much
longer than adrenalin. In addition the hippocampus is an early
mechanism to suffer problems in ageing – possibly due to the
sustained influence of cortisol induced by stress.
Stauth & Khalsa (1999) suggest that in normal functioning the
hippocampus, more than other brain areas, secretes a hormone that
eventually switches off cortisol production. However older people have
lost 20-25% of hippocampal cells, so this feedback is impaired. The
cortisol production continues producing further damage to the
hippocampus.
28
Stress and performance
Disturbed concentration – this is the other (cognitive) symptom of
stress (the other being problems in memory). McFarlane et al.
(1993) using ERPs (event-related potentials) compared PTSD
patients with controls in a task that had to discriminate tones.
The PTSD patients had considerable difficulties selectively
attending to the target tones. McFarlane et al. proposed that
PTSD patients had a dysfunction in their noradrenaline function,
which has a crucial role in selective attention. This resulted in
slowed RTs and is probably also linked to the impairments in
memory shown in PTSD patients.
29
Stress and behavioural performance
Behavioural manifestations
As mentioned before stress can produce problems in the following
areas:
1. Absenteeism from work
2. Sleep disruption
1. Absenteeism
In 2004 in the UK a survey revealed that 52% of businesses had
had an increase in absenteeism due to stress.
30
Stress and behavioural performance
1. Absenteeism (continued)
Woo et al. (1999) compared working conditions in which there were
poor environmental stressors (e.g. uncomfortable temperature
working in a kitchen) with there were psycho-social stressors
(high workload, dysfunctional work tensions).
They found that more days were taken off for mild illnesses for
environmental stressors compared to psycho-social stressors.
On the other hand, when the psycho-social stressors were high
people were more likely to report minor illnesses, but not
actually take time off work.
So absenteeism relates to stress only in terms of the physical work
conditions. However, actual productivity is unlikely to be helped
when there are poor psycho-social conditions, if it means there
is going to be more minor illnesses while people try to keep on
working instead of taking rest.
31
Stress and behavioural performance
2. Sleep disruption
States et al. (2003) have suggested that chronic sleep disruption is the
major symptom in the PTSD patient. They further suggest that if left
untreated that this could lead to long term damage in brain physiology.
To overcome this they suggest the application of drug therapy. They
reviewed 7 clinical cases of PTSD with the treatment of Olanzapine.
As a result of such treatment all patients had improved sleep and there
was also improvement in other PTSD symptoms.
It is perhaps difficult sorting out cause-and-effect – does stress cause loss
of sleep or loss of sleep lead to stress – however…
Disturbed sleep, measured by no. of hours of sleep lost, can lead to higher
risk of heart attacks and age-related symptoms such as Type 2
diabetes. This is to to due hormonal imbalance especially in the
cortisol rhythm. Also, melatonin, produced during sleep, is an antioxidant that prevents DNA damage. Disturbed sleep reduces its effects.
32
Stress and emotional effects
Stress can lead to:
1. Anxiety and depression
2. Physical tension
1. Stress and anxiety and depression
Stress and anxiety are interrelated in that situations, or your own
thoughts, can make you frustrated or anxious. The extent to
which you have these reactions is described as stress.
The symptoms of anxiety are perspiration, trembling or twitching,
muscle tension (including headaches), dry mouth and stomach
ache. There can be accompanying physiological symptoms,
such as dizziness, diarrhoea, irritability, lack of sleep and so on.
33
Stress and emotional effects
Anxiety and depression (continued)
In the case of depression, there can be a certain
degree of circularity – stress may lead to
depression and the state of being depressed
means that one copes poorly with day-to-day
stresses.
The incidence is 1 in 4 women and 1 in 10 men
will suffer depression at some point in their
lives. It is believed that women are more prone
due to greater hormonal changes. However,
situational circumstances may be a
contributory factor as well.
From a biochemical viewpoint there appears to be
under-activity in the frontal cortex and overactivity in the limbic system. But life events
can also be a trigger. On the other hand, some
individuals appear to be more prone to
depression.
Depression
Stress
Reduced
coping
34
Stress and emotional effects
2. Stress and physical tension
Groups of muscles (in the shoulder, neck and head) tend to tighten in
response to stress, which over time becomes painful. Consequently
physical tension can be reduced by focussing on these muscle groups.
Most would agree that tension headaches are the result of continued
contraction of the pericranial muscles*. Pain is very difficult to evaluate
in these circumstances, for example, is this due to faulty posture, or is
one more sensitive to pain because of emotional state?
Carlsson et al. (1990) in Sweden compared 2 treatments for chronic
tension headaches (which had persisted on average for 9 years)
involving either acupuncture or physiotherapy. Both groups improved
for 7-12 months after treatment, with the physiotherapy group having
the edge in terms of reduction of intensity of headache and in overall
well-being.
[*muscles in the outer surface of the skull]
35
Stress and emotional effects
Stress and physical tension (continued)
In the Carlsson study the physiotherapy consisted of helping them (1) to
understand the factors leading to headaches – psychosocial stress,
muscular stress, drug overuse; (2) showing that pain can be relieved
without analgesics, instead showing them how to use relaxation, automassage, cryotherapy* and Transcutaneous** Electrical Nerve
Stimulation (TENS); (3) smoothed stretching of the contracted
muscles; (4) broader information was given on body awareness during
stress, allowing enough time for rest and sleep.
Thus although the physiotherapy was a central part, there were other
aspects that were covered too. These other aspects do not appear to
have been given to the acupuncture patients.
[*cryotherapy = using low temperature;**transcutaneous = through or by
way of the skin]
36
Stress: the brain, body and performance
Topics that have been covered
Types of stress:
1. Physiological – The SAM & HPA systems, the GAS syndrome
(Selye), effects on health, esp immunity.
2. Performance
(a) Cognitive – Yerkes-Dodson, effects on memory &
concentration.
(b) Behavioural – Absenteeism, sleep disorders
3. Emotional – physical tension, anxiety & depression
Still to be covered
Interventions
1. Transactional stress-coping
2. Stress inoculation
3. Biofeedback
4. Social Support
5. Drugs
37
Interventions to alleviate stress
There do seem to be effects of stress on
health and on performance. What
kinds of interventions would be
worthwhile for the practitioner, support
agencies or the individual to try out?
We shall look at this under 5 main
headings:
1. Transactional stress coping
2. Stress inoculation
3. Biofeedback and relaxation
4. Improving social support
5. Drugs
38
Transactional stress-coping model
Interventions to relieve
This is perhaps more a model than an
stress: transactional stressintervention that is not confined to
psychology and is used in
coping
medicine and in the social
sciences.
For example in the field of diabetes, a
patient has to cope with their own
qualities (e.g. gender, SES, age,
Person
personality) and the support that
Environmental
demands
they hope to get from others
(family, friends, social
organisations) and into the melting
pot are important life events (job
Outcome
loss, family death, divorce,
Symptoms of stress
separation, etc.)
Subsequent quality of life is an
outcome that the patient adjusts to
along with glycemic control.
A more general model is illustrated on
the right.
39
Interventions to relieve stress:
transactional stress-coping
•
•
•
Matthews (2000) suggests that a
person’s subjective response in a
situation is based on their cognitions
and the environmental demands.
If a task is seen as overloading then
this is distressing. On the other hand
tasks seen as challenging promote
engagement.
These conclusions were based on
work in which people had to
complete a stress state questionnaire
examining motivational, emotional
and cognitive responses. Stress was
equated with negative aspects of
these 3 entities: lack of motivation,
emotional tension and intrusive
thoughts.
40
Interventions to relieve stress:
transactional stress-coping
Conclusions on the transactional model
•
•
•
Such work moves the focus away from a
single dimension of arousal/stress. Instead
something like the transactional model may
be more reflective of brain structures.
Transactional theory acknowledges that the
way individuals perceive their environment is
a critical facet of any stress that they may
experience.
It may also be a way forward for practitioners
in helping people to cope with stress.
41
Interventions to alleviate stress:
stress inoculation
•
Cognitive therapy is used for anxiety
and depression whereby irrational
and negative thoughts are replaced.
• Meichenbaum (1985) suggests that
instead of applying this just to
extreme cases, it should be used
earlier. He developed stress
inoculation training to be done in 3
phases:
1. Assessment – the problem is
discussed and the person’s views
on how to get rid of it are taken into
account.
2. Reduction of stress - relaxation
techniques are learned. Self-coping
statements are learned:
2a. Preparing for a stressor –
(“Suppose X happens – what should
I do?”)
2b. Confronting a stressor (“Start deep
breathing…”)
2c. Coping with feeling overwhelmed
(“try to reduce it to manageable
level…”)
3. Application and follow through
These techniques are used in different
scenarios and perhaps used in role
play. Then used in real life.
Finally, as a technique it appears to be
an effective treatment – probably
when it can effectively transfer
easily to new situations.
42
Stress reduction training:
Meichenbaum (1977) – from Eysenck
Assessment
What’s the
Problem?
Stress reduction techniques
Relaxation
“Keep calm,
I can cope”
Self-instruction
There’s no point
in worrying”
Application and
follow-through
Imagine and role-play
Stress-reduction
techniques
Apply in real
life context
43
Interventions to alleviate
stress: biofeedback
Biofeedback – definition
A person is given ongoing
information about some aspect
of their physical functioning.
E.g. EMG (electromyograph) on
the forehead can give auditory
feedback on muscle tension.
Similarly a GSR (galvanic skin
response) can monitor and give
feedback on the degree of
perspiration due to tension.
Training is given for relaxation.
Three stages of feedback
1. Awareness – getting insight
into that physiological response
(e.g. pulse rate, tension in a
particular area).
2. Gaining control – learning in a
peaceful place how to control.
This might include rewards for
success.
3. Transfer into real life.
44
Interventions to alleviate
stress: biofeedback
•
The autonomic system controls
various aspects of our
functioning – heart rate, blood
pressure, skin temperature and
brain waves. These are all
aspects that we can’t directly
control.
• However, with biofeedback we
can exert indirect control over
these by such activities as
relaxation and deep breathing.
Evidence
On the positive side several
laboratory and clinical studies
report positive effects.
For example, a review by
Blanchard (1994) concludes
that biofeedback can reduce
blood pressure.
On the negative side:
• We don’t know why it works.
• Some effects may just be due to
relaxation training, or due to
inducing a sense of control.
• It doesn’t seem to be likely to
work for those who have a
“driven” way of living.
45
Interventions to alleviate stress:
Social support
This is a popular suggestion in magazines for combating
stress – that one needs a “social network”.
There is a distinction between structural and functional
social support. Structural support is the basic network
and functional support is about the quality of that
network.
It is functional support that appears to be important to
health and well-being. Whereas a large structural
network can have a negative effect if it is very time
consuming to maintain (Shaefer et al. 1981).
E.g. a review by Uchino et al. (1999) showed that blood
pressure was lower for those with high levels of social
support. They conclude: “Social support may
influence mortality via changes in cardiovascular,
endocrine and immune systems”.
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Interventions to alleviate stress: drugs
People going to their GP to
alleviate stress can be
prescribed a drug. Here are the
most common types:
Benzodiazepines- (e.g. Valium,
Librium) – they are effective and
are used by millions.
But they have side effects – they
can act like sedatives. Can
cause memory problems,
depression and interact with
alcohol.
Higher probability of accidents.
Dependency – of those taking for at
least 1 year, only 43% managed
to stop for at least a week.
Buspirone – has advantages over
the benzodiazepines. It helps
the effects of serotonin and
doesn’t act as a sedative or have
marked withdrawal problems.
But its side effects are
headaches and depression. It is
less effective with severe stress
as it takes 2 weeks to take
effect.
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Interventions to alleviate stress:
drugs (continued)
Beta blockers – these reduce activity in
the sympathetic nervous system by
reducing heart rate and lowering
blood pressure (helping treatment of
heart disease). This affects the
body, rather than the brain.
Lau et al. (1992) showed that they
reduced death risk by 20% for those
with heart disease.
There are no dependence problems.
Side effects include cold
extremities, hallucinations and
tiredness.
Summing up on drugs for stress clearly professionals and patients
find drugs useful for reduction of
intense stress.
But the causes of the stress are not
dealt with directly (e.g. life style,
etc.)
Also they can have side effects. E.g.
Ashton (1997) recommends that
benzodiazepines should only be
used for 4 weeks AND only to those
with severe symptoms AND only
minimal dose. Those already
dependent, should have the dose
reduced. 70% of dependent users
who are motivated, can give them
up for several years.
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Stress: the brain, body and performance
Topics that have been covered
Types of stress:
1. Physiological – The SAM & HPA systems, the GAS syndrome
(Selye), effects on health, especially immunity.
2. Performance
(a) Cognitive – Yerkes-Dodson, effects on memory &
concentration.
(b) Behavioural – Absenteeism, sleep disorders
3. Emotional – physical tension, anxiety & depression
Interventions
1. Transactional stress-coping
2. Stress inoculation
3. Biofeedback
4. Social Support
5. Drugs
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Concluding remarks
As we have seen stress is a condition that is produced by a number of
factors, and it can have serious underlying biological consequences.
Academics argue about some of the main concepts such as the inverted
U-shaped effect of performance as a function of arousal; but the clinical
manifestations of stress and anxiety are fairly clear: there is an
association between stress and many physical and mental problems.
Related to this, the immune system is implicated but there is some
ambivalence in the actual findings, suggesting that the relationship, for
instance, between type A and heart disease is not a strong one.
The impact of everyday events varies across people, but certain people
appear to be more sensitive to these stressors. Are these real or just
more exaggerated?
Various therapies have been outlined that can lead to improvements in
people’s condition. The evidence appears to suggest that there is likely
to be more long-term success if people can learn to take control of their
stresses by learning appropriate techniques and at the same time try to
wean away from a dependence on drug treatments.
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