Schizophrenia Flashcards
(19 cards)
Biological Explanations - Genetic Basis
- Knowledge
- family studies - the risk of schizophrenia increases with the genetic similarity of a relative who has the disorder
- for example someone with an aunt who has schiz has a 2% chance of also having it, this increases to 9% for a sibling and 485 if they are an identical twin
- although family members share aspects of the environment so there is a correlation between both, family studies show strong support for the role of genes in schiz. - candidate genes - there are several different genes involved in schizophrenia making it polygenic
- the most likely ones are those which code for neurotransmitters such as dopamine
- there has been a study done by ripke et al which compared all previous data of genome wide studies of schiz, he compared the genetic make up of 37,000 people w it and a control group of 113,000 people
- he found that there was 108 different genetic variations associated with the risk of schiz
- this makes it aetiologically heterogenous - role of mutation - even with the absence of the disorder in ones family history, there can still be genetic origins
- this can be explained by mutation in parental dna caused by infections and radiation etc
- there is a positive correlation between paternal age and the risk of schiz increasing from 0.7% for fathers under 25 and over 2% for fathers aged 50+
Biological Explanations - Genetic Basis
- Evaluation
- research support - family studies such as Gottesman show the risk increases in genetic similarity of a family member who has schiz
- adoption studies such as Tinari’s show that biological children of parents who have schiz have heightened risk of also having it, regardless of whether they grew up in an adoptive family
- twin studies show a concordance rate of 33% for MZ twins and 7% for DZ twins
- shows that people are more vulnerable due to their genetic make up - environmental factors - limitation
- these can include biological and psychological factors
B - include birth complications or smoking THC-rich cannabis in teenage years
P - includes childhood trauma which leaves people more vulnerable to adult mental health problems in general
- specific link to schiz is shown in the study done by Morkved showing that 68% of people with schiz reported at least 1 childhood trauma compared to 38% of a matched control group w/o schiz
- so genetic factors alone cannot explain schiz
Biological Explanations - Neural Correlates
- Knowledge
- dopamine hypothesis
- based on the discovery that drugs used to treat schiz have caused symptoms similar to those in patients with parkinsons which is associated with too little DA levels
- so schiz might be caused by too high DA levels in subcortical areas of the brain
- for example, excess DA receptors in pathways from the subcortex to brocas area can cause symptoms such as speech poverty - updated version of the DA hypothesis
- Davis et al found that different parts of the brain such as the PFC have too little DA (hypodopamingeria) and in other deeper brain regions
- this causes symptoms such as delusions and hallucinations
- so essentially schiz is caused by too little or too much DA levels in diff brain regions
- so cortical hypodopamingeria can lead to hyperdopamingeria and result in cognitive problems and psychotic symptoms
- these imbalances of DA can be explained by genetics or early life experiences.
Biological Explanations - Neural Correlates
- Evaluation
- evidence for dopamine - strength
- anphetamines can increase DA, worsen the symptoms of people w schiz and induce symptoms into people w/o schiz
- antipsychotics lower DA activity and decreases the intensity of symptoms of schiz
- candidate genes act on production of DA receptors
- strongly suggests that doapmine is involved in symptoms of schiz - glutamate - limitation
- live scanning studies and post mortems have shown there is an increase in levels of glutamate in several brain regions of those w schiz
- candidate genes are involved in glutamate prodcution
- makes an equally strong case for other neurotransmitters having an affect on schiz symptoms
Psychological Explanations - Family
- Knowledge
- Schizophregenic Mother
- Proposed by Reichman and based on patient reports of a particular type of parent
- this is known as the schizophregenic mother and can be chatacerised by being cold, rejecting or controlling
- this leads to a family climate of tension and secrecy
- can then lead to distrust, paranoia and delusions in the child and ultimately schiz - double-blind theory
- proposed by bateson, emphasis on communication style in families
- focuses on mixed messages by parents to their children who feel trapped or confused
- they are often punished for doing the wrong thing without actually knowing what this is and not having clear rules
- then punished with the withdrawal of love and leaves children feeling confused about the world and thinking its dangerous
- this leads to them having symptoms such as paranoia and disorganised thinking
- however it has been made clear that this is just a risk factor, not a direct cause of schiz - expressed emotion (ee)
- high levels of negative emotion expressed by family members to someone with schiz
- includes things like verbal criticsm often with violence, hostility like anger and rejection and emotional over-involvement
- these high levels of ee cause stress and can lead to the onset of schiz in someone who is already vulnerable due to their genetic makeup or can worsen it and cause a relapse in someone recovering from it
Psychological Explanations - Family
- Evaluation
- research support
- studies do link childhood trauma and abuse, insecure attachment to schiz
- for example those who have schiz are disproportionately more likely to have insecure attachment, particularly type c or d
- also a study done by read et al has shown that 69% of women and 59% of men with schiz have had a history of abuse
- Morkved et al also has shown that adults with schiz have reported at least 1 childhood trauma in their life - shows a strong risk factor
- therefore, shows that family dysfunctional environments can contribute to schiz - explanations lack support
- there is poor evidence for theories like the schizophregenic mother and double blind
- this is because they are based on clinical observations and informal assessments rather than systematic evidence
- there is a poor link and these family explanations cannot account for the link between childhood trauma and schiz.
Psychological Explanations - Cognitive
- Knowledge
- dysfunctional thinking
- schiz is linked with dysfunctional though processing
- ventral striatum dysfunction can be linked to negative symptoms
- temporal and cingulate gyri dysfunction can be linked to hallucinations
- reduced though processing in both of these areas can lead to cognitive impairments
frith et al came up with 2 dysfunctional though processes :
- metarepresentation (ms) dysfunction
- ms allows us to self reflect and understand our own actions as well as others and insight into our own intentions and goals
- dysfunction to this can disrupt the ability to recognise our own thoughts as being carried out by ourselves rather than others
- this can lead to hallucinations and delusions such as though insertions ( thinking thoughts are implanted by others ) - central control dysfunction
- cc allows us to supress automatic responses when we perform actions
- dysfunction of this can lead to speech derailment and thoughts being triggered uncontrollaby and people with schiz cannot supress their thoughts and speech triggered by other thoughts
- they cant filter their thoughts which can also lead to disorganised thinking
Psychological Explanations - Cognitive
- Evaluation
- research support
- evidence shows support for dysfunctional thought processing
- john stirling et al did a study where he compared performance of a cognitive task in 30 people with schiz and 30 people w/o it
- he used the stroop task where ppts had to name the font-colour of colour words while supressing the urge to read them aloud
- it was found that people w schiz took twice as long to read the font colours out
- supports friths idea of central control theory - cognitive processes in people w schiz is impaired - proximal explanation
- cognitive theories only explain proximal causes so what is happening now to cause the symptoms rather than distal explanations such as what is the original cause of the disorder such as genetics or family dysfunction origins
- hard to see how childhood trauma or genetics links to metarepresenation or central conrol issues
- cognitive theories alone only provide a partial explanation for schiz.
Biological Therapy - Typical Antipsychotics
- Knowledge
- Drug Therapy
- main treatment for schiz is drugs known as antipsychotics
- they can be used to reduce symptoms like hallucinations or delusions
- they can be used short term or long term depending on the severity of the patient
- two types are typical antipsychotics and atypical antipsychotics - typical antipsychotics
- produced in the 1950s - example is chlorpromazine
- acts as a dopamine antagonist and blocks DA receptors and reduces neurotransmitter action
- initially, the DA levels build up but this production is reduced overtime
- links to the DA hypothesis - reduced DA levels normalises key brain areas and reduces symptoms such as hallucinations
- have a sedative affect
- chlorpromazine is known to have a calming affect and so is used in agitated patients in hospitals
- believed to have an affect on histamine receptors which causes sedation
- can be used alongside other treatments, not just schiz
Biological Therapy - Atypical Antipsychotics
- Knowledge
- Introduced in the 1970’s aimed to be more effective than typical ones with fewer side affects
- variety of these exist but their exact mechanisms are not fully understood
Clozapine :
- Developed in 1960’s, reintroduced in 1970s because of their effectiveness and then withdrawn because they caused risk of a fatal blood condition but introduced again because they were more effective than other antipsychotics
- Target dopamine, serotonin and glutamate and decreases depression and anxiety in schiz
- Lowers the suicide risk which is important as 30-50 % of schiz patients commit
- Only to be taken via injection or be closely monitored due to their serious side effects
Risperidone :
- Made as an alternative to Clozapine, to be as effective but have less serious side effects
- Also bind to da and serotonin receptors but they bind more strongly than clozapine so a smaller dosage can be used
- Evidence to suggest that there is a lower risk of serious side effects by taking these instead
Biological Therapy
- Evaluation
- Research support for effectiveness
- there is much research to support the effectivness of atypical and typical antipsychotics
- for example - Ben Thornley did a review of 13 trials which showed that chlorpromazine improved overall functioning and reduced symptom severity compared to a control group
- herbert meltzer also found that atypical antipsychotics such as clozapine was effective in 30-50 % of treatment-resistant cases where other drugs had failed
- so antipsychotics are effective, but it can vary
- however, a counterpoint of this is that Davis et al found that these research studies may overestimate their effectiveness
- this is because the have flaws such as only showing the short term effects, selective data publishing and exaggerating positive outcomes
- antipsychotics also have a very sedative calming affect meaning they make patients appear better than actually reducing their symptoms
- so their effectiveness is weaker than originally appeared
- serious side effects
- both atypical and typical AS have side effects such as dizziness, weight gain and sleep issues
- they can cause things like tardive dyskeneisa which is involuntary facial movements due to dopamine sensitivity
- also things like neuroleptic malignant disorder (NMS) - rare but fatal condition which can lead to comas, delirium and high fever
- clozapine can also affect the immune system and cause infections
- therefore, these side effects may cause patients to want to stop treatment and reduce their effectiveness - mechanisms are unclear
- how AS works are still unclear
- we have a link to the original DA hypothesis suggesting schiz is because of overactive DA, new research challenges this
- if dopamine isnt the only cause, then blocking it may not be the best treatment
- so uncertainty about their works raises doubts about how and who they work for.
Psychological Therapy - CBT
- Knowledge
Cognitive Behaviour Therapy :
- Helps patients under and cope with their symptoms
- Encourages patients to challenge their irrational beliefs and thoughts
- Doesnt fully eliminate their symptoms but allows them to cope better and function better
- Reality testing - helps them to question their delusions and misinterpretations
- Reduces symptoms of anxiety and depression in those with schiz
Psychological Therapy
- Evaluation
- Evidence for effectiveness
- Sameer Jahaur reviewed 34 studies of CBT on Schiz and found that there was small but significant effects on both positive and negative symptoms
- Maria Pontillo - Also found that effectiveness of cbt reduced the frequency and severity of auditory hallucinations
- NICE also has recommended CBT based on research and clincal observations - Quality of evidence - cbt methods and symptoms of schiz vary widely between cases
- Neil Thomas found that different case studies used different cbt methods for different symptom combinations
- therefore it is hard to determine whether cbt is effective for individual patients
Psychological Therapy - Family
- Knowledge
Family Therapy :
- involves family members and the identified patient
- aims to reduce stress and improve family communication style to prevent relapse
- links w earlier theories of schiz mother and double blind
- pharoah et al identified key benefits :
- reduces stress and negative emotions
- improves the family ability to help and encourages balanced problem solving and support
- enhances communication and reduces expressed emotions and therefore reduces relapse risk
Frank Burbach proposed a model of support :
1. Basic support
2. Identify resources
3. Mutual understanding
4. Address issues
5. Skills training
6. Relapse preventing
7. Long term prevention
Psychological Therapy - Family
- Evaluation
- evidence for effectiveness
- william mcfarlane found that family therapy is one of the most effective treatments for schiz
- it reduced relapse rates by 50-60%
- it is even more beneficial when mental health starts to decline
- NICE also recommends it for anyone diagnosed w schiz
- can be used and effective in early stages and in severe cases - benefits the whole family
- not just for identified patient, benefits other family members
- fiona labbon and christine barrowclough found that family support is most crucial as they provide the most care
- improves family functioning as it reduces the negative impacts of schiz on other members
- so overall strengthens families ability to help patient
- has wider benefits
Management of Schizophrenia
- Knowledge
-2. token economies for schiz :
- used as a reward system to promote positive behaviours
- Ayllon and Azrin used a token economy for women w schiz in a hospital :
- tokens were given for tasks such as cleaning etc
- these tokens could then be exchanged for rewards such as watching films etc
- it was found that the completion of the tasks increased significantlly
- however the use declined as psychiatric hopsitals closed and there were ethical concerns aroud restricting freedoms for people w mental illnesses
- rationale for token economies
- institutionalisation can cause things such as poor hygenie or social withdrawl due to prolonged hospital stays
- johnny mateson found 3 instituional behaviours : - personal care
- condition related behaviours
- social behaviour
- modifiying these w token economies can help to improve the quality of life for those in hospitals and also help normalise behaviurs and reintegrate those back into society
- what is token economies ? :
- type of behaviour modification - operant conditioning
- they are coloured disks given immediately after desired behaviour is portrayed
- target behaviours are tailored to each individual
- these tokens have no actual value but can then be exhcnaged for tangible rewards
- they are primary reinforcers and then secondary reinforcers because of their association with the rewards
- but rewards MUST be meaningful for the patient in order for the system to be effective.
Management of Schizophrenia
- Evaluation
- evidence for effectiveness
- Krista Glowacki reviewed 7 high quality studies of token economies on people w schiz in hospitals
- found a reduction in negative symptoms and unwanted behaviours
- supports the idea that TE is valuable in managing schiz
- COUNTERPOINT : - limited sample size, so a smaller sample base as it is only 7 studies
- file drawer problem - positive results published, negative ones hidden and so creates bias
- creates serious doubts about the claims of TE helping w schiz - reliability - ethical concerns
- raised concerns over control - give professionals power over patients behaviour
- imposing one persons norms onto others and also not identifiying target behaviours sensitively is problematic
- may cause more distress to those who are already struggling
- due to ethical concerns about this the use of it has decreased
- therefore, their benefits may be outweighed by the freedom restrictions and short term quality of life reductions - alternative approaches
- there are more ethical and less controversial methods to manage schiz
- these studies do have some methodological issues and less consistent evidence, however they suggest positive effects.
for example Michael Chiang suggested art therapy as it is high gain and low risk of side effects, abuse etc
- NICE also recommends this as a way to manage
Interactionist approach to schiz
- Knowledge
- Diathesis-stress model
- this suggests that vulnerability so a diathesis and stress are needed to develop schiz
- other factors alone such as biological predispositions cannot account for it - stress will be what triggers the onset
- meehl’s model :
- originally it was thought that schiz is completely genetic and there was a “schizogene” which later developed into a schizotypic personality
- meehl suggests that carrying this gene and also a chonric stress such as trauma will lead to developing schiz
- he says that without the gene, no amount of stress will trigger schizophrenia
modern understanding of diathesis :
- we now know that there are other factors influencing schiz such as multiple genes and things like psychological trauma
- the trauma is now the diathesis rather than the stressor
- john read suggests a neurodevelopmental model stating that the earlier and more severe the trauma, the more affect it will have on the developing brain
- so these early developmental issues can lead to more vulnerability to stress later in life
modern understanding of stress :
- oringally stress was referred to by parenting style
- modern defintion is anything that can trigger schiz such as psychological trauma, early stressors and environmental factors
- one includes smoking cannabis which leads to higher risk of schiz due to its affect on dopamine - causes dysregulation
treatments according to this approach :
- interactionist combines both biological and psychological treatments
- most combine kind is antipsychotics + cbt
- douglas turkington points out that biological causes of schiz can be accepted as long as they are treated w cbt for psychological symtpoms
- has interactionist approach and accpets both perspectives
- in uk it is more common to use both medication and therapy together whereas in the us it is more common to just use medication
Interactionist approach to schiz
- Evaluation
- support for vulnerability and triggers
- Tienari did a study where he studied genetic vulnerability and psychological triggers
- followed 19,000 finish adoptees whos biological mothers all had schiz
- found that those who had a higher genetic risk + dysfunctional parenting had more chance / risk of schiz than those with high genetic risk but a healthy family
- so genetic vulnerability and family stress increases risk of schiz - diathesis and stress are too complex
- original model was way too simplistic
- we now know that many other genes contribute to vulnerability
- also stress can come in many different forms such as biological ( dopamine dysregulation due to cannabis use) or psychological like childhood trauma
- shown in study by james houseton who found that childhood sexual abuse emerged as an influence for vulnerbaility to schiz and cannabis as a major trigger
- so both biological and psycholgical factors influence schiz - real world application
- interactionist approach supports the combination of biological and psychological treatments
- practical advantage as combining medication and therapy improves effectiveness
- study done by tarrier who supports this - randomly assigned 315 patients to diff treatment groups - medication + cbt
- medication + counselling
- medication only (control)
- found that combination groups had more reduced symptoms than medication only
- so therefore, interactionist approach is more effective than single-treatment methods.
