Psychopathology Flashcards
(90 cards)
1
Q
What are the definitions of abnormality.
A
Statistical infrequency
Deviation from social norms
Failure to function adequately
Deviation from ideal mental health
2
Q
Describe statistical infrequency.
A
When an individual has a less common characteristic.
3
Q
Describe deviation from social norms.
A
Concerns behaviour that is different from the accepted standards of behaviour in a community or society.
4
Q
Evaluate statistical infrequency.
A
- real life application (diagnosing intellectual disability disorder)
- all assessment of patients with mental disorders include some kind of measurement of how severe their symptoms are compared to statistical norms. It is thus useful in clinical assessments.
- unusual characteristics can be positive and just because they’re abnormal, doesn’t necessarily mean they need to be treated. Means statistical infrequency can’t be used alone to make a diagnosis.
- labelling someone as abnormal might have a negative effect on the way others view them and the way they view themselves.
5
Q
Evaluate deviation from social norms.
A
- real-life application in the diagnosis of antisocial personality disorder.
- deviation from social norms is never the sole reason for defining abnormality.
- social norms vary from one culture and generation to another, this makes it hard to define abnormality across cultures.
- too much reliance on deviation from social norms can lead to systematic abuse of human rights. Diagnoses were really there to maintain control over minority ethnic groups and women.
6
Q
Describe failure to function adequately.
A
Occurs when someone is unable to cope with ordinary demands of day-to-day living.
7
Q
Describe deviation from ideal mental health.
A
Occurs when someone does not meet a set of criteria for good mental health.
8
Q
Evaluate failure to function adequately.
A
- includes the subjective experience of the individual, means it is a useful criterion for assessing abnormality.
- it is hard to determine whether something is failing to function adequately and whether it is a deviation from social norms.
- treating something as a failure to function adequately can limit personal freedom and can discriminate against minority groups.
- judging whether someone is failing to function is subjective and someone has the right to make a judgement that the patient may not agree with.
9
Q
Evaluate deviation from ideal mental health.
A
- covers a broad range of criteria for mental health
- some ideas in Jahoda’s criteria are culture-bound, specific to Western European and North American cultures
- sets an unrealistic standard for mental health, the criteria would see everyone as abnormal as it is near impossible to have every trait
10
Q
What is an example of statistical infrequency?
A
IQ and intellectual disability disorder.
The average IQ is set at 100, most people have an IQ between 85 and 115. Only 2% have a score below 70 and these people are classed as abnormal.
11
Q
What is an example of deviation from social norms?
A
Antisocial personality disorder.
A symptom is the absence of prosocial internal standards associated with failure to conform to lawful or culturally normative ethical behaviour. So, a psychopath is abnormal because they don’t conform to our moral standards.
12
Q
Who proposed signs that someone is failing to function adequately, and what were these?
A
David Rosenhan and Martin Seligman
- when a person no longer conforms to standard interpersonal rules.
- when a person experiences severe personal distress.
- when a person’s behaviour becomes irrational or dangerous to themselves or others.
13
Q
What is an example of failing to function adequately?
A
Intellectual disability disorder.
An individual must be failing to function adequately as well as having a statistical infrequency to be diagnosed.
14
Q
Who created the good mental health criteria and what did it entail?
A
Marie Jahoda
- we have no symptoms or distress
- we are rational and can perceive ourselves accurately
- we self-actualise (reach our potential)
- we can cope with stress
- we have a realistic view of the world
- we have good self-esteem and lack guilt
- we are independent of other people
- we can successfully work, love and enjoy our leisure
15
Q
What is a phobia?
A
An irrational fear of an object or situation.
16
Q
What is the DSM system?
A
A system used to classify and diagnose mental health problems. It stands for Diagnostic and Statistical Manual of Mental Disorder. The DSM is updated every so often as ideas about abnormality change, the current version is the 5th edition and so is thus the DSM-5.
17
Q
What are all phobias characterised by?
A
Excessive fear and anxiety, triggered by an object, place or situation. The extent of the fear is out of proportion to any real danger presented by the phobic stimulus.
18
Q
What does the DSM recognise as phobias and related anxiety disorders?
A
- specific phobia = phobia of an object or situation
- social anxiety (social phobia) = phobia of a social situation
- agoraphobia = phobia of being outside or in a public place
19
Q
What are the behavioural characteristics of phobias?
A
Panic
Avoidance
Endurance (remaining in presence of phobic stimulus but with high levels of anxiety)
20
Q
What are the emotional characteristics of phobias?
A
Anxiety (unpleasant state of high arousal, prevents relaxation and makes it difficult to experience positive emotion)
Anxiety is long term
Fear is the immediate unpleasant response from a phobic stimulus
21
Q
What are the cognitive characteristics of phobias?
A
Selective attention to the phobic stimulus
Irrational beliefs
Cognitive distortions
22
Q
What is depression?
A
A mental disorder characterised by low mood and low energy levels.
23
Q
How does the DSM recognise depression and depressive disorders?
A
- major depressive disorder = severe but often short-term depression
- persistent depressive disorder = long-term or recurring depression, including sustained major depression and what used to be called dysthymia
- disruptive mood dysregulation disorder = childhood temper tantrums
- premenstrual dysphoric disorder = disruption to mood prior to and/or during menstruation
24
Q
What are the behavioural characteristics of depression?
A
- activity levels (reduced levels of energy, has the effect of dropping out of school/ work and their social life) OR (psychomotor agitation = struggling to relax so they end up pacing up and down a room)
- disruption to sleep and eating behaviour (reduced sleep = insomnia) OR (increased need for sleep = hypersomnia)
- aggression and self-harm
25
What are the emotional characteristics of depression?
- lowered mood
- anger
- lowered self-esteem
26
What are the cognitive characteristics of depression?
| processing info about the world differently
- poor concentration
- attending to and dwelling on the negative
- absolutist thinking (when a situation is unfortunate they tend to see it as an absolute disaster)
27
What is OCD?
Obsessive - compulsive disorder
| A condition characterised by obsessions and/or compulsive behaviour
28
What are the DSM-5 categories of OCD?
Repetitive behaviour accompanied by obsessive thinking.
- OCD = obsessions (recurring thoughts/images) and/ or compulsions (repetitive behaviours)
- Trichotillomania = compulsive hair pulling
- Hoarding disorder = compulsive gathering of possessions and the inability to part with anything regardless of its value
- Excoriation disorder = compulsive skin picking
29
What are the behavioural characteristics of OCD?
- Compulsions
^ compulsions are repetitive
^ compulsions reduce anxiety
- Avoidance (attempt to reduce anxiety by keeping away from situations that trigger it)
30
What are the emotional characteristics of OCD?
- Anxiety and distress
- Accompanying depression
- Guilt and disgust
31
What are the cognitive characteristics of OCD?
- Obsessive thoughts (thoughts that recur over and over again)
- Cognitive strategies to deal with obsessions
- Insight into excessive anxiety (individuals are aware that their obsessions and compulsions are not rational but they still experience catastrophic thoughts about the worst case scenario. They tend to be hypervigilant = they maintain constant alertness and keep attention focused on potential hazards)
32
Who proposed the two-process model and what does it state?
Hobart Mowrer
The two-process model is based on the behavioural approach to phobias. It states that phobias are acquired by classical conditioning and then continue because of operant conditioning.
33
What is classical conditioning and how does it relate to phobias?
Classical conditioning is learning by association, two stimulus are repeatedly paired together (UCS and NS). The NS then produces the same response as the UCS.
With phobias we associate something we initially have no fear of (NS) with something that already triggers a fear response (UCS).
34
What is the evidence for using classical conditioning for phobias?
John Watson and Rosalie Rayner, little Albert.
Albert showed no unusual anxiety towards a white rat before the study. The experimenters tried to give him a phobia by making a loud frightening noise whenever the rat was presented.
Noise = UCS, this creates fear = UCR
Rat = NS and is presented with the noise = UCS, both of these then produce fear = UCR.
Albert then became fearful of the rat, the rat is now a CS that produces a CR.
35
What is operant conditioning and how does it relate to phobias?
Operant conditioning is learning where behaviour is shaped and maintained by its consequences. For phobias, they are often long lasting and Mowrer explained this as a result of operant conditioning. Reinforcement tends to increase the frequency of a behaviour, negative reinforcement is where an individual avoids a situation that is unpleasant.
Mowrer suggested that whenever we avoid a phobic stimulus we escape the fear and anxiety we would have suffered if we had remained. This reduction in fear reinforces the avoidance behaviour and so the phobia is maintained.
36
Evaluate the two-process model.
- strength is that the model was a step forward as it went beyond Watson and Rayner's concept.
- was important for therapies as it explains that patients need to be exposed to their feared stimulus to prevent practising their avoidance.
- not all avoidance behaviour associated with phobias are the result of anxiety reduction e.g. agoraphobia, model can't explain this.
- model is incomplete, some aspects of phobic behaviour require further explaining. e.g. Bounton, evolutionary factors.
- sometimes people develop a phobia and are not aware of having had a related bad experience, model can't explain this.
- What about the cognitive aspects of phobias? Model doesn't include these aspects.
37
What is systematic desensitisation?
It is a behavioural therapy designed to gradually reduce phobic anxiety through the principle of classical conditioning. If the sufferer can learn to relax in the presence of the phobic stimulus, they will be cured. Systematic desensitisation makes the individual learn a new response to the phobic stimulus.
38
What is counter-conditioning?
Learning a new response to a phobic stimulus, the phobic stimulus is paired with relaxation instead of anxiety.
39
What is reciprocal inhibition?
It is impossible to be afraid and relaxed at the same time, so one emotion prevents the other.
40
What are the three processes involved in SD?
| Describe them.
1. The anxiety hierarchy - this is put together by the patient and therapist, it is a list of situations related to the phobic stimulus that provoke anxiety arranged in order from least to most frightening.
2. Relaxation - the therapist teaches the patient to relax as deeply as possible e.g. breathing exercises or mental imagery techniques, meditation or by using drugs like Valium.
3. Exposure - the patient is exposed to the phobic stimulus while in a relaxed state. This takes place across several sessions, starting at the bottom of the anxiety hierarchy. When the patient can stay relaxed during the low levels on the hierarchy, they move up until staying relaxed in situations high on the hierarchy.
41
What is flooding?
A behavioural therapy in which a phobic patient is exposed to an extreme form of a phobic stimulus in order to reduce anxiety triggered by that stimulus. The exposure to the phobic stimulus is immediate. Flooding sessions are typically longer than SD sessions, one session lasting two - three hours. However, sometimes only one flooding session is needed to cure a phobia.
42
How does flooding work?
Flooding stops phobic responses very quickly, this is because without the option of avoidance, the patient quickly learns the the phobic stimulus is harmless.
In some cases the patient may achieve relaxation in the presence of the phobic stimulus because they become exhausted by their own fear response.
43
What does extinction mean in classical conditioning terms?
A learned response is extinguished when the CS is encountered without the UCS. The result is that the CS no longer produces the CR.
44
What are the ethics surrounding flooding?
Flooding is not unethical but it is an unpleasant experience so it is important that patients give full informed consent to the procedure and that they are fully prepared for the session.
An ethical problem surrounding flooding is that once the patient agrees to take part in the session, they don't have the chance to withdraw.
45
Evaluate systematic desensitisation.
- research shows that SD is effective in the treatment of specific phobias e.g. Gilroy et al.
- is it suitable for a range of people, unlike flooding.
- it is acceptable to patients and patients prefer it as it doesn't cause the same degree as trauma as flooding does.
- there are low refusal and attrition (no. of people dropping out) rates of SD.
46
Evaluate flooding.
- it's cost-effective, flooding is highly effective and quicker than alternatives.
- it is less effective for some types of phobia such as complex phobias like social phobia.
- the treatment is traumatic for patients and this often means patients are unwilling to see it through to the end. This means time and money are wasted preparing patients only to have them refuse to start the complete treatment.
47
What did Aaron Beck suggest about explaining depression?
That a cognitive approach can explain why some people are more vulnerable to depression than others. In particular it is a person's cognitions that create this vulnerability (the way they think).
48
What are the three parts to Beck's cognitive vulnerability?
- faulty information processing
- negative self-schemas
- the negative triad
49
Explain the faulty information processing.
When depressed we attend to the negative aspects of a situation and ignore positives. We also tend to blow small problems out of proportion and think in 'black and white' terms.
50
Explain negative self-schemas.
A schema is a package of ideas and information developed through experience, a self-schema is the package of information we have about ourselves. We use schemas to interpret the world, so if we have a negative self-schema we interpret all information about ourselves in a negative way.
51
Explain the negative triad.
A person develops a dysfunctional view of themselves because of three types of negative thinking that occur automatically, regardless of the reality of what is happening at the time.
a - negative view of the world
b - negative view of the future
c - negative view of the self
52
What other psychiatrist suggested a different cognitive explanation of depression and what did he propose?
Albert Ellis and he proposed that good mental health is the result of rational thinking, defined as thinking in ways that allow people to be happy and free of pain. To Ellis, conditions like anxiety and depression (poor mental health) result from irrational thoughts (any thoughts that interfere with us being happy and free of pain).
53
What is the ABC model?
How irrational thoughts affect our behaviour and emotional state.
A - activating event
B - beliefs
C - consequences
54
What is an activating event?
An external event that triggers irrational thoughts. According to Ellis, we get depressed when we experience negative events and these trigger irrational beliefs.
55
What is a belief (in ABC model)?
Irrational beliefs.
Musturbation = we must always succeed or achieve perfection.
I-can't-stand-it-itis = belief that it is a major disaster whenever something does not go smoothly.
Utopianism = belief that life is always meant to be fair.
56
What is a consequence (ABC model)?
When an activating event triggers irrational beliefs there are emotional and behavioural consequences.
57
Evaluate Beck's cognitive theory of depression.
- good supporting evidence, supports the idea that depression is associated with faulty information processing, negative self-schemas and the cognitive triad of negative automatic thinking. Grazioli and Terry assessed 65 pregnant women for cognitive vulnerability and depression before and after birth. They found that those women judged to have been high in cognitive vulnerability were most likely to suffer post-natal depression. Clark and Beck reviewed research on this topic and concluded that there was solid support for all these cognitive vulnerability factors. Critically these cognitions can be seen before depression develops, suggesting that Beck may be right about cognition causing depression, at least in some cases.
- forms the basis of a cognitive behaviour therapy (CBT), all cognitive aspects of depression can be identified and challenged in CBT like the negative triad. This is a strength because it translates well into a successful therapy.
- cannot explain why some depressed patients are deeply angry and why they have this extreme emotion. Some sufferers also suffer hallucinations and bizarre beliefs that can't be explained. Some suffer Cotard syndrome, the delusion that they are zombies (Jarret 2013).
58
Evaluate Ellis's ABC model.
- it's true that some cases of depression follow activating events (reactive depression) but this is different and Ellis can't explain different depression that arises without an obvious cause.
- it has led to a successful therapy in that by challenging irrational negative beliefs, a person can reduce their depression. This is supported by evidence (Lipsky et al). This supports the basic theory because it suggests the irrational beliefs had some role in the depression.
- It doesn't easily explain the anger associated with depression or the fact that some patients suffer hallucinations and delusions.
59
What is CBT and how does it work?
Cognitive behaviour therapy
CBT begins with an assessment where the patient and therapist clarify the patient's problems. They then identify goals for the therapy and put together a plan to achieve them. A central task is to identify where there might be negative or irrational thoughts that will benefit from challenge. CBT then works to change the negative and irrational thoughts and put more effective behaviours into place.
60
What are the two types of CBT?
Beck's cognitive therapy
| Ellis's rational emotive behaviour therapy (REBT)
61
Explain Beck's cognitive therapy.
The idea behind this therapy is to identify automatic thoughts about the world, the self and the future (negative triad), these thoughts must then be challenged. Cognitive therapy aims to help patients test the reality of their negative beliefs, the patient is the scientist and is set to investigate the reality of their negative beliefs. If the patient then provides a negative statement the therapist can then produce this evidence and prove the statement wrong.
62
Explain Ellis's rational emotive behaviour therapy.
REBT extends the ABC model to the ABCDE model, including dispute and effect. The main aim of REBT is to identify and dispute irrational thoughts. To challenge an irrational belief an argument is involved, the effect is to change the belief and break the link between the negative life event and depression.
63
What are the two types of argument used in REBT?
Empirical argument = disputing whether there is actual evidence to support the negative belief.
Logical argument = disputing whether the negative thought logically follows from the facts.
64
What is behavioural activation?
Encouraging a depressed patient to be more active and engage in enjoyable activities. This provides more evidence for the irrational nature of beliefs.
65
What are the strengths of CBT?
- there is evidence to support the effectiveness of CBT.
March et al compared the effects of CBT with antidepressants, and then with CBT mixed with antidepressants with 327 adolescents. After 36 weeks 81% of the CBT group, 81% of the antidepressant group and 86% of the CBT and antidepressant group were significantly improved. Therefore CBT is very effective.
66
What are the weaknesses of CBT?
- CBT may not work for severe cases of depression, such as those who cannot motivate themselves to engage with the therapy. If this is the case it is possible to provide medication and do CBT later, this means that CBT can't be used as the sole treatment for all cases of depression.
- Rosenzweig suggested that all psychotherapies share one essential ingredient - the relationship, success may be due to the therapist - patient relationship not then the therapy technique. Simply having someone to talk to who will listen could be what matters most.
- CBT focuses on the present and future, not the past. Some patients are aware of the link between their childhood experience and depression and so want to talk about these, they struggle to find the present focus.
- emphasis on what is happening in the mind of the individual may minimise the importance of the circumstances in which a patient is living (McCusker). CBT techniques used inappropriately can demotivate people to change their situation.
67
What approach links to each condition?
```
phobias = behavioural approach
depression = cognitive approach
OCD = biological approach
```
68
What are the forms of the biological explanation for OCD?
Genetic explanations
| Neural explanations
69
Explain the genetic explanation for OCD.
Genes are involved in the individual vulnerability to OCD. (Lewis research). What is passed on from one generation to the next is genetic vulnerability not the certainty of OCD. The diathesis-stress model states that certain genes leave some people more likely to suffer a mental disorder but it is not certain. Some environmental stress is necessary to trigger the condition.
70
Find evidence to support genetic explanations for OCD.
Lewis 1936 observed that of his OCD patients 37% had parents with OCD and 21% had siblings with OCD. This suggests OCD runs in families.
71
What are candidate genes?
Genes that create vulnerability for OCD.
Some of these genes are involved in regulating the development of the serotonin system e.g. the gene 5HT1-D beta is implicated in the efficiency of transport of serotonin across the synapse.
72
What does it mean when OCD is polygenic?
That OCD is not caused by one single gene but that several genes are involved.
Taylor analysed findings of previous studies and found evidence that up to 230 different genes may be involved in OCD. These can include those associated with the action of dopamine and serotonin. Both have a role in regulating mood.
73
What does aetiologically heterogeneous mean?
That the origin of OCD has different causes.
One group of genes may cause OCD in one person but a different group of genes may cause the disorder in another person.
There is also evidence to suggest that different types of OCD may be the result of particular genetic variations.
74
Explain the neural explanation for OCD.
That the genes associated with OCD are likely to affect the levels of key neurotransmitters as well as structures of the brain.
75
Explain the role that serotonin has in OCD.
The neurotransmitter serotonin is believed to help regulate mood, neurotransmitters are responsible for relaying information from one neuron to another. If a person has low levels of serotonin then normal transmission of mood-relevant information doesn't take place and mood and other mental processes are affected.
76
Explain the role that decision making systems have in OCD.
Some cases of OCD (in particular hoarding disorder) seem to be associated with impaired decision making. This may be associated with abnormal functioning of the lateral of the frontal lobes, the parts that are responsible for logical thinking and decision making. There is also evidence to suggest that an area called the left parahippocampal gyrus associated with processing unpleasant emotions functions abnormally in OCD.
77
Evaluate genetic explanations for OCD.
- there is evidence that some people are vulnerable to OCD as a result of their genetic make-up. This can be twin studies, Nestadt et al reviewed previous twin studies and found that 68% of identical twins shared OCD opposed to 31% of non-identical twins.
- Psychologists haven't been successful at pinning down all the genes involved (candidate genes). This is because several genes are involved and each genetic variation only increases risk of OCD by a fraction.
- environmental factors can also trigger or increase the risk of OCD (diathesis-stress model). Cromer et al found that over half the OCD patients in their sample had a traumatic experience in their past and that OCD was more severe in these. Means OCD cannot be entirely genetic in its origin.
78
Evaluate neural explanations for OCD.
- there is evidence to support the role of some neural mechanisms in OCD e.g. some antidepressants work purely on the serotonin system, increasing these levels. Such drugs are effective in reducing OCD symptoms. OCD symptoms also form part of a number of other conditions that are biological in origin e.g. Parkinson's Disease (Nestasdt et al 2010).
- research in decision making in OCD has identified that other brain systems may be involved sometimes but no system has been found that always plays a role in OCD. We cannot therefore really claim to understand the neural mechanisms involved in OCD.
- Neurotransmitters and structures of the brain not functioning normally in OCD is not the same as saying that these cause OCD. The abnormalities could be a result of OCD.
79
What is co-morbidity and how does it evaluate OCD.
Co-morbidity is having two disorders together, many people who suffer OCD become depressed. This depression may involve disruption to the serotonin system, this may mean that the serotonin system is disrupted in many patients with OCD because they are depressed as well.
80
Twin studies are used to support OCD being genetic, what is a limitation to twin studies?
They make the assumption that identical twins are only more similar that non-identical twins in terms of their genes, but overlook the fact that identical twins may also be more similar in terms of shared environments.
81
What is used to treat OCD?
Drug therapy.
82
What is drug therapy?
Treatment involving drugs, drug therapy aims to increase or decrease levels of neurotransmitters in the brain or to increase/ decrease their activity.
83
What is the main treatment for OCD symptoms?
A type of antidepressant drug called a selective serotonin reuptake inhibitor (SSRI). SSRI works on the serotonin system in the brain.
84
How do SSRIs work?
Serotonin is released by certain neurons in the brain, it is released by the presynaptic neurons and travels across a synapse. The neurotransmitter chemically conveys the signal from the presynaptic neuron to the postsynaptic neuron and then it is reabsorbed by the presynaptic neuron where it is broken down and re-used.
By preventing the re-absorption ad breakdown of serotonin, SSRIs effectively increase its levels in the synapse and thus continue to stimulate the postsynaptic neuron. This compensates for whatever is wrong with the serotonin system in OCD.
85
Describe what SSRIs are prescribed.
Dosage and other advice vary according to which SSRI is prescribed. A typical daily dose of Fluoxetine is 20mg although this may be increased if it is not benefiting the patient. The drug is available as capsules or liquid. It takes three to four months of daily use for SSRIs to have much impact on symptoms.
86
What can be combined with SSRI for treatment of OCD?
Drugs are often used alongside cognitive behavioural therapy (CBT) to treat OCD. The drugs reduce a patient's emotional symptoms and means that they can engage more effectively with the CBT.
87
What are the alternatives to SSRIs?
```
When an SSRI is not effective after three or four months the dose can be increased or it can be combined with other drugs. Sometimes other antidepressants are tried.
Tricyclics (an older type of antidepressant) are sometimes used e.g. Clomipramine. These have the same effect on the serotonin system SSRIs. Clomipramine tends to have more severe side effects than SSRIs so it is generally kept in reserve.
SNRIs (serotonin-noradrenaline reuptake inhibitors), these are a different class of antidepressant drugs that have been used to treat OCD. These are also a second line of defence for patients who don't respond to SSRIs. SNRIs increase levels of serotonin as well as another different neurotransmitter - noradrenaline.
```
88
Evaluate drug therapy in relation to treating OCD.
- there is evidence for the effectiveness of SSRIs in reducing OCD symptoms. Soomro et al reviewed studies comparing SSRIs to placebos in the treatment of OCD and concluded that all studies showed significantly better results for the SSRIs than for placebo conditions.
- Drug treatments are cheap compared to psychological treatments, using drugs is therefore good value to public health systems. SSRIs are also non-disruptive to patients' lives.
- Drugs may have side effects, indigestion, blurred vision and loss of sex drive. These are usually only temporary however reduce effectiveness because people stop taking them.
- some psychologists believe the evidence favouring drug treatments is biased because the research is sponsored by drug companies who do not report all the evidence (Goldacre 2013).
- OCD is believed to be biological and so it makes sense for treatment to be biological, but OCD can also have a range of other causes such as a response to a traumatic life event.
89
How effective are SSRIs?
Effectiveness is greatest when SSRIs are combined with psychological treatment (CBT). Typically symptoms decline significantly for around 70% of patients taking SSRIs. Of the remaining 30% alternative drug treatments or combinations of drugs and psychological treatments will be effective for some.
90
What are the side-effects of clomipramine?
Side-effects are more common and can be more serious. More than 1 in 10 patients suffer erection problems, tremors and weight gain. More than 1 in 100 become aggressive and suffer disruption to blood pressure and heart rhythm.
