Schizophrenia Flashcards

Question

# Biological Explanations for SZ: Dopamine Hypothesis What are the 3 Dopamine Hypothesis explanations for SZ?

Answer 1

- Neurotransmitters - Hyperdopaminergia in the subcortex - Hyperdopaminergia in the cortex

Answer 2

NTs = brain's chemical messengers - NT's appear to work differently in the brain of patients with SZ (dopamine in particular) - Dopamine is important in the fuctioning of several brain systems that may be implcated in the symptoms of SZ

Answer 3

(OLD DH) - High levels/activity of dopamine in the subcortex (central areas of the brain) may have implications for symptoms of SZ - E.g an excess of dopamine receptors in Broca's area (responsile for speech production) may be associated with speech poverty or auditory hallucinatons

Answer 4

(NEW DH) - Goldman-Rakic et al (2004): identified a role of low levels of dopamine in the prefrontal cortex (responsible for thinking and decision making) in the negative symptoms of SZ

Answer 5

1. Negative symptoms 2. Positive symptoms

Answer 6

- Avolition = loss of motivation - Motivation involves anticipation of a reward - Certian regions of the brain are believed to be associated witth this anticipation e.g the ventral striatum - Abnormaility in the VS may therefore be involved i the develoment of avolition - Juckel et al (2006) - found lower levels of activity in the VS of SZ patients in controls. They also observed a negative correlation between activity levels in the VS and severity of overall negative symptoms. Therefore, activity in the VS is a neural correlate of negative symptoms of SZ

Answer 7

- Allen et al: scanned brains of SZ patients who experience auditory hallucinations while they identified voice clips as either their own or someone else's voice. Compared to controls, the SZ patients had lower activation levels in the superior temporal gyrus (processes sound) and anterior cingulate gyrus (processes emotion) The hallucination group also made more errors than the control group. - Therefore, we can conclude that reduced activity in these 2 areas of the brain is a neural correlate of auditory halucination

Answer 8

:) Lots of evidence: Gottesman, Tienari, Ripke - SZ isnt just biological (biologically reductionist) - if concordance rates of MZ twins is less than 50%, something else must be playing a part - MZ twins encounter a more similar environment: assumes DZ and MZ share similar amounts of environment, but, as MZ twins are treated more similarly, they experience more 'identity confusion' (Joseph 2004) = So, MZ and DZ twins reflect nothing more than environemntal differences that distinguish between the 2 types of twins

Answer 9

:) Evidence from treatment: success of drug treatments that attempt to change levels of dopamine activity in the brain - Leucht et al: carried out a meta-analysis of 212 studies where all of the antipsychotic drugs tested were more effective than the placebo in the treatment of positive and negative symptoms (reduced effects of dopamine) :( Challenges to the new and old DH: Noll 2009 - strong evidence against both whereby he argues antipsychotic drugs dont alleviate hallucinations and delusions in about 1/3 of people experiencing these symptoms (also, dopamine levels normal in some and still experiencing hallucinations and delusions)

Answer 10

:( Correlation-causation problems: useful in flagging up particular brain systems that may not be workin properly but don't prove that unusual activity ina certain region of the brain causes a symptom - neural correlates tell us relatively little

Answer 11

1. Family dysfunction 2. Cognitive explanations

Answer 12

1. SZ mother 2. Double blind theory 3. Expressed emotion

Answer 13

- Fromm-Reichmann (1948) = many of her patients spoke of a particular type of patient (SZ Mother) - Characteristics of SZ Mother: cold, rejecting, controlling, creates a family climate characterised by tension and secrecy - Leads to distrust that later develops into paranoid delusions and ultimately SZ

Answer 14

- Bateson et al (1972) - emphasised the role of communication within a family as a risk factor of SZ - The child regularly finds themselves trapped in situations where they feat doing the wrong thing, but recieve mixed messages about what this is - When the child 'gets it wrong' (often), they are punished with a withdrawal of love, which leaves the child thinking the world is confusing and dangerous, and is reflected in symptoms like disorganised thinking and paranoid delusions

Answer 15

- The level of (usually negative) emotion expressed towards a patient by their carers Contains several elements: - Verbal criticism (and violence often) - Hostility (anger and rejection) - Emotional over-involvement in the life of the patient - These high levels of EE are a serious source of stress for the patient and often cause relapse in SZ patients - Could also ge te stress that triggers the onset of SZ in a;ready vulnerable people e.g those with a genetic link to SZ - Diathesis stress model

Answer 16

1. Metarepresentation 2. Central Control

Answer 17

- Focus on the role of mental processes - SZ is characterised by disruption to normal thought processing, suggesting that cognition is likely to be impaired - Frith et al (1992): identified 2 kinds of dysfunctional thought processing that could underlie some symptoms: metarepresentation and central control

Answer 18

- The cognitive ability to reflect on thoughts and behaviour - Allows us to have insight into our intentions and goals, and to interpret actions of others - Dysfunction in metarepresentation would disrupt our ability to recognise our behaviour and thoughts as our won, and not somebody else's - Explains auditory hallucinations and delusions such as one's own thought insertion (someone projecting thoughts into one's own mind)

Answer 19

- The cognitive ability to suppress automatic responses while we perform deliberate actions instead - Inability to do this may lead to disorganised speech and thought disorder - SZ sufferers tend to experience derailment of thoughts and spoken sentences because each words trigger associations, and the patient cannot suppress automatic responses to these

Answer 20

:)/:( Support for family dysfunction as a risk factor: Read et al (2005) - 69% of female and 59% of male SZ in-patients had a history of physical abuse, sexual abuse, or both during childhood. Berry et al (2008) - adults with secure attachments to their primary caregiver are more likely to have SZ. BUT, info about childhood experiences was gathered after SZ symptoms had developed, so memories may have been distorted - weakens validity :( Lack of evidence for SZ Mother and double-blind theory: both theories based on clinical observations of patients, and assessing the patients mothers for 'crazy-making characteristics' :( SZ Mother is socially sensitive: blame parents of SZ sufferers when parents are already dealing with having a child with SZ (adds unnecassary added trauma) - makes Mothers socially feel ashamed when they may not be the cause of the SZ

Answer 21

:) Strong evidence for cognitive explanations: Stirling et al (2006) - compared 30 SZ sufferers to 18 controls on the Stroop test. Patients took twice as long as controls to name the ink colours - supports central control theory (provides validity) :( can't infer causes of SZ from cognitive explanations: links between symptoms and faulty cognition are clear, but we don't kow the origins of these conditons

Answer 22

:( Don't consider biological factors: could be that both biological and psychological factors can seperately produce the same symptoms - diathesis stress model - SZ more likely due to genetic vulnerability and triggered by stress - reductionist

Answer 23

Antipsychotics

Answer 24

- Typical antispychotics (traditional) - Atypical antipsychotics (second-generation)

Answer 25

- Reduce the effects of dopamine - Act as a dopamine antagonist - they bind to dopamine but don't stimulate dopamine receptors (blocks their action) - By blocking the dopamine receptors in the synapses of the brain - reduces action of dopamine - Reduces positive symptoms - hallucinations and delusions

Answer 26

Chlorpromazine

Answer 27

- Initially, when a patient begins taking Chlorpromazine, dopamine levels build up and then its production is released - According to the dopamine hypothesis, this normalises neurotransmission in key areas of the brain - reduces symptoms like hallucinations - Also, has a sedation effect, so it's also used to calm patients

Answer 28

- The aim of developing new antipsychotics (atypical) was to improve upon the effectiveness of drugs in suppressing symptoms of psychosis (such as SZ) and also minimise the side effects - They target a range of NTs, including dopamine and serotonin (a higher affinity to serotonin) - They also block dopamine receptors but only occupy them temporarily and then rapidly dissociate to allow normal dopamine transmission (this accounts for the lower extrapyramidal side effects)

Answer 29

Clozapine Risperidone

Answer 30

- Binds to dopamine receptors but also acts on serotonin and glutamate receptors - More effective than typical antipsychotics - reduces depression and anxiety in patients and improves cognitive functioning - Also improves mood - important as 30-50% of SZ sufferers attempt suicide at some point

Answer 31

- As good but safer than Clozapine (fewer side effects) - Developed due to clozapine causing some deaths due to a blood condiiton called agranulocytosis - Risperidone also binds to dopamine receptors - Binds more strongly to dopamine receptors than Clozapine and is therefore effective in much smaller doses than most antipsychotics and has fewer side effects

Answer 32

:) Evidence of effectiveness: Thornley et al (2003) - found Chlorpromazine was associated with better overall functioning and reduced symptom severity compared to a placebo - relapse rate was lower in group taking the antipsychotic. Meltzer (2012) - Clozapine is effective in 30-50% of cases where typical antipsychotics have failed :( Serious side effects: Typical antipsychotics associated with: dizziness, agitation, sleepiness, stiff jaw, weight gain, itchy skin. Atypical antipsychotics were developed to reduce side effects, but they still exist. Overall, antipsychotics aren't a problem-free treatment :( Problems with the evidence for effectiveness: Healey (2012) - suggested that some successful traits have had their data published multiple times, exaggerating the evidence of their effectiveness - and because antipsychotics have calming effects, its easy to demonsgrate they have positive effects on ptients (not the same as reducing psychosis) :( The chemical cosh argument: chemical cosh = drugs used to subdue patients at an institution. Antipsychotics are used in hospitals to calm patients and make them easier to work with, rather than the benefit of the patients. Moncrieff (2013) - while short term use is recommended by the National Institute of Health and Clinical Excellence to calm patients, this can be seen as human rights abuse

Answer 33

- CBT - Family Therapy - Token Economies

Answer 34

- 5-20 sessions - Can occur in groups or individually - Helps patients to identify irrational thoughts and change them - Considers less-threatening possibilities of the patients belief - Won't remove symptoms of SZ but can help them to cope with them by allowing them to make sense of how their feelings are impacted - Just knowing where their symptoms come from can reduce a patients anxiety - Delusions may be challenged so the patient can learn they're not a reality

Answer 35

- Takes place within the family environment - Aims to improve communication between family members - Originally based on the idea that family is the root of the problem (EE) Stratergies: - Form a therapeutic alliance with all family members - Reduces stress of caring for a relative with SZ - Improve family's ability to anticipate and solve problems - Help family members achieve a balance between caring and maintaining their own lives - These stratergies reduce levels of EE and stress, while increasing the chances of patients complying with medication - Reduces likelihood of relapse and re-admission to hospital

Answer 36

- Reward systems used to manage patients maladaptive behaviours that have developed as a result of spending long periods of time in psychiatric hospitals e.g spending all day in pjs, bad hygiene - Doesn't cure SZ but improves quality of life, meaning patients will find it easier to live outside of a hospital setting - Tokens e.g coloured discs are given immediately to patients when they have carried out a desirable behaviour as a form of operant conditioning (immediacy is important) - Tokens have no value in themselves, but they can just be swaped later for rewards - Could be sweets, magazines, cigarettes or services e.g having room cleaned - Tokens are secondary reinforcers - only have one value once the patient has learnt that they can be exchanged for rewards

Answer 37

:) Supporting evidence for effectiveness of psychological treatments: Jauhar et al (2014) - found cbt has a small but significant effect on both positive and negative symptoms of SZ. Pharoah et al (2010) - found family therapy significantly reduces hospital readmission and improves the quality of life for patients and their famillies = both CBT and family therapy are valid ways of treating SZ :( Issues with evidence: results are inconsistent across different studies - many small-scale studies comparing patients before and after psychological treatments have found positive results but these studies often lack a control group, or patients aren't randomly allocated to their treatment condition = supporting evidence for psychological therapies is problematic :( The treatments don't cure SZ: They improve quality of life but dont cure SZ so psychological treatments are weak overall :( Token economies have ethical issues: rewards more available to those with mild symptoms, as those with severe symptoms may be unable to comply with desirable behaviours = severely ill patients are discrimated against :( CBT has ethical issues: challenging a patients paranoia can interfere with freedom of thought e.g if a patient beleived the government was highly controlling, challening this belief could easily stray into modifying their politics = therapists should be careful :( There are alternative treatments: e.g NICE recommends art theraoy as a way of distracting patients from their symptoms = less well-resarched options may be better alternatives

Answer 38

- Also known as the biosocial approach - Acknowledges there are biological, psychological and societal factors in the development of SZ Biological Factors - Genetic Vulnerability - Neurochemical and neurological abnormality Psychological Factors - Stress (life events and daily hassles)

Answer 39

- Diathesis = Vulnerability - Stress = a negative psychological experience - The diathesis stress model says that both a vulnerability to SZ and a stress-trigger that are necessary to develop SZ - One or more underlying factors make a person particularly vulnerable to developing SZ but the onset of the condition is triggered by stress

Answer 40

- Diathesis was the result of a single 'schizogene' - This led to the development of a 'schizotypic personality', a characteristic of which was a sensitivity to stress - According to Meehl, is a person doesn't have the schizogene, then no amount of stress could lead to SZ - Carriers of the gene, however, who experience chronic stress through childhood and adolescence (particularly those with a SZ Mother), could get SZ

Answer 41

- Many genes appear to increase genetic vulnerability slightly (Ripke et al 2014) - Diathesis may not just be egentic, but could include psychological trauma - Read et al (2001): Proposed a neurodevelopmental model in which early trauma alters the developing brain - Early and severe enough trauma e.g child abuse can seriously affect brain development e.g the hypothalamic-pituitary-adrenal (HPA) system can become over0-active, maing the individual more vulnerable to later stress

Answer 42

- A modern definition of stress includes anything that risks triggering SZ A lot of research has considered cannabis use as a trigger for SZ - Cannabis is a stressor because it increases SZ risk by up to 7x (likely because cannabis interferes with the dopamine system) - However, most people who smoke cannabis don't develop SZ, so there must be one or more vulnerability factors

Answer 43

- As the interactionist approach acknowledges both biological and psychological factors in SZ, it's compatible with both biological and psychological treatments - Most common combination: antipsychotics and CBT - Unusual to treat SZ with psychological therapies alone, all 3 of the are usually accompanied by antipsychotics

Answer 44

:) Support for the effectiveness of combinations of treatments: Turkington et al (2006): not possible to use combinations of treatments without adopting an interactioist approach. Tarrier et al (2004): 315 patients randomly allocated to a medication and CBT group, medication and supportive councelling group, or a control group (medication only). Patients in the 2 combination groups showed lower symptom levels than those in the control group. :( We don't know how diathesis and stress work: strong evidence to suggest that some sort of underlying vulnerability coupled with stress can lead to SZ - However, we dont yet fully understand the mechanisms by which the symptoms of SZ appear and how both vulnerability and stress produce them = intercationist approach is incomplete :( The original diathesis-stress model is oversimple (single schizogene and schizophrenic parenting style as the major source of stress): multiple genes increase vulnerability to SZ, each having a small effect on its own; there is no single schizogene - furthermore, stress can come in many different forms

Schizophrenia Flashcards

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