schizophrenia Flashcards
what are positive symptoms?
additional experiences to those of a ordinary person
- hallucination and delusions
what are negative symptoms?
the loss of usual abilities and experiences
- avolition
- speech poverty
what are hallucinations?
sensory experiences
- hearing voices
- seeing things that arent there
what are delusions?
irrational beliefs
- e.g. thinking you’re related to a famous historical figure
- make people behave in ways that seem normal to them but bizarre to others
what is avolition?
finding it difficult to begin or keep up with goal directed activity
Lack of motivation
- e.g in hygiene or grooming
what is speech poverty?
a reduction in the amount or quality of speech in a person
what is a strength of diagnosis and classification?
it has high reliability
- high inter rater reliability (+97)
- high test retest reliability (+92)
what are limitations of diagnosis and classification?
Co-morbidity
- Buckley et al found that around half of those diagnosed with Sz also had depression or substance abuse
Gender Bias
- Men more likely to get diagnosed to women - 1.4:1 ratio
- women may not be getting diagnosed or the treatment necessary
Culture Bias
- British African-Caribbean 10x more likely to get diagnosed with Sz
- Haitians believe hearing voices are their ancestors
what are the genetic explanations for Sz?
- Family studies
- Candidate genes
- Role of mutation
what is family studies?
having a family member with Sz increase the chance of developing it
- 43% for identical twin
- 9% for sibling
what is candidate genes?
how faulty genes could cause schizophrenia
- most likely genes coding for Dopamine
- Ripke et al found 108 genetic combinations increasing vulnerability to Sz
what is the role of mutation?
a mutation in parental DNA can cause Sz
- can come from radiation, poison or viral infection
- evidence comes from correlation of Paternal age and Risk of Schizophrenia
Strength of Genetic Approach
Evidence
- Gottesman large scale family study found someone with an Sz aunt has a 2% chance, Sz sibling 9%, Sz identical twin 43%…
- Tienari et al found that biological children of a parent with Sz still have a high chance even when growing up with adoptive family
- Hilke et al found a correlation of 33% in identical twins and 7% in non-identical twins
Limitations of Genetic approach
Environmental factors
- risks in birth complications (Morgan et al)
- Cannabis smoking in teenage years (Di Forti et al)
- Childhood trauma - 67% correlation (Morkved)
what is Neural explanations to Sz?
- original dopamine hypothesis
- updated dopamine hypothesis
what is the original dopamine hypothesis?
- drugs treating Sz caused symptoms similar to Parkinsons - a condition associated with low DA levels
- Schizophrenia may be due to high DA levels in subcortical areas of the brain (hyperdopaminergia)
- e.g. high levels of DA receptors in Brocas area causing auditory hallucinations
what is the updated dopamine hypothesis
Davis proposed the idea of abnormally low DA receptors in the brain (hypodopaminergia)
- it has been suggested that Cortical hypodopaminergia leads to Subcortical hyperdopaminergia
- abnormal DA function origins in genetic variation and early experiences of stress (Howes)
strength of the neural explaination
Evidence supporting
- Amphetamines increase DA Amphetamines worsen symptoms of those with Sz and can induce it in those without (Curran et al)
- Antipsychotics reduce DA and also reduce intensity of symptoms (Tauscher et al)
limitation of the neural explaination
Glutamate
- post mortem brain scans have shown high levels of glutamate in those with Sz
- suggests the role of other neurotransmitters
what is Family Dysfunction?
- the Schizophrenogenic Mother
- Double-bind Theory
- Expressed Emotion
what is the Schizophrenogenic mother?
- Fromm-Reichmann proposed idea
- meaning schizophrenia causing mother
- many of their patients talked of a particular type of parent
- the mother is cold, controlling and rejecting - leading to family climate of tensions and secrecy
- leads to distrust - develops in delusions and ultimately schizophrenia
what is Double-Bind theory?
- Bateson suggested if a developing child often find themselves trapped in situations where they fear doing the wrong thing, but receive mixed messages and can comment on the unfairness or seek clarification
- When they get it ‘wrong’ they are punished by the withdrawal of love
- Makes world seem confusing and dangerous
- often leads to dysfunctional thinking and paranoid delusions
what is Expressed Emotion?
the level of emotion expressed to a person with Sz by their carers
- verbal criticism often accompanied by violence
- hostility - e.g. anger and rejection
- Emotional over involvement - e.g. needless self-sacrifice
this causes stress in the individual and is often a cause of relapse but can also be a trigger for a vulnerable person
Strength of Family Dysfunction
Research Support
- Read et al found that those with Sz are disproportionately more likely to have insecure attachments (usually type C or D)
- Read et al also found 69% of men and 59% of women with Sz have a history of physical or sexual abuse
- Morkved et al also found that 67% of people with Sz had childhood trauma
Limitations of Family Dysfunction
Lack of Support
- although there is plenty of evidence for childhood family-based stress correlating with adult Sz, there is almost none for traditional family based theories
- Schizophrenogenic Mother and Double Bind are both based on clinical observation of people with Sz but lack systematic evidence
what are the cognitive explainations?
- Dysfunctional thinking
- Metarepresentation dysfunction
- Central control dysfunction
what is Dysfunctional thinking?
- Reduced thought processing in the Ventral Striatum is associated with negative symptoms
- Reduced processing in the Temporal and Cingulate Gyri is associated with Hallucinations
what is Metarepresentation dysfunction?
Frith identified metarepresentation
- the cognitive ability to reflect on thoughts and behaviours
- dysfunction would disrupt our ability recognise our own actions and thoughts as being our own
- this would explain hallucinations like hearing voices
what is Central Control Dysfunction?
Frith also identified issues with our cognitive ability to suppress Automatic while we perform Deliberate Actions
- Speech poverty and Thought Disorder could result from the inability to suppress automatic thoughts and speech triggered by other thoughts
Strength for the cognitive explanation?
Research support
- Stirling et al compared 30 people with Sz to a 30 person control group on cognitive tasks
- in the Stroop task (naming the font colour of word colours) people with Sz took more than 2x as long on average
Limitation of Cognitive Explanation
Proximal Explanation
- only explain what is happening now to produce symptoms
- possible distal explanations are Genetic and Family Dysfunction
- cognitive theory may only provide partial explanation
what are Typical Antipsychotics?
- Developed 1950’s
- e.g. Chlorpromazine
- work as an antagonist in the dopamine system
- block dopamine receptors
- reduces symptoms of hallucinations
- also has sedative properties
what are Atypical Antipsychotics?
- Developed 1970’s
- made to improve effectiveness and reduce side effects
- Clozapine
- Risperidone
what is Clozapine?
- Atypical antipsychotic
- binds to receptors sites of Dopamine, Serotonin and Glutamate
- improves mood, reduces depression and increases cognitive function
- often prescribed to those at risk of suicide
what is Risperidone?
- Atypical Antipsychotic
- binds to receptors sites of Dopamine, Serotonin and Glutamate
- binds to Dopamine receptors more strongly than Clozapine
- can be taken in smaller doses to reduce side effects
Strength of Antipsychotics
Evidence for Effectiveness
- Herbert Meltzer found that clozapine is the more effective than other atypical and typical antipsychotics
- was effective in 30-50% of treatment resistant cases where typical antipsychotics wouldve failed
Limitations of Antipsychotics
Side Effects
- Tardive Dyskinesia (caused by dopamine supersensitivity) causes involuntary facial movements: grimicing, blinking and lipsmacking
- Neuroleptic Malignant Syndrome (caused by dopamine blocked in Hypothalimus) causes: high temp, delirium, coma and even fatality
Partial Understanding
- the understanding of antipsychotics is based on the Original Dopamine Hypothesis
- We know the Original Dopamine Hypothesis is not a proper explanation for Sz
what is Cognitive Behaviour Therapy in Schizophrenia?
- helps patients make sense of their irrational cognitions (hallucinations and delusions)
- understanding where their symptoms come from can be hugely helpful
- although it does not eliminate the condition its helps people cope with them
- people hearing voices can be told that they are experiencing an extension to ordinary thinking in words - this is Normalisation
Strength of CBT in schizophrenia
Evidence for Effectiveness
- Jauhar et al reviewed 34 studies of CBT on Sz - found clear evidence for small but significant effect on both positive and negative symptoms
- Maria Pontillo et al found a decrease in frequency and severity of auditory hallucinations
Limitations of CBT in schizophrenia
CBT Doesn’t Cure
- only helps patient cope with symptoms
- largely biological syndrome so CBT cant fully cure
Quality of Evidence
- Thomas suggests different studies have involved the use of different CBT techniques and combination of people with positive and negative symptoms
- benefits could be different for each technique or symptoms
what is Family Therapy?
- takes place with family as well as the identified patient
- aims to improve the communication and interaction of family
what was suggested for structuring Family Therapy?
Burbach proposed a model for working with families with Sz
- begins with sharing basic information and providing support
- Phase 2 involves identifying resources that family member can offer
- Phase 3 encourages mutual understanding
- Phase 4 identifies unhelpful patterns of interaction
- Phase 5 is about skills training
How does Family therapy help?
Pharoah identified strategies that family therapists use
- reduces levels of Expressed Emotion (especially negative emotion) - reduces likelihood of relapse
- Encourages family to form a therapeutic alliance to improve beliefs and behaviours about Sz
Strengths of Family therapy
Evidence for Effectiveness
- McFarlane concluded that it was the most effective treatment
- relapse rate reduced by 50-60%
- NICE recommends family therapy for anyone with Sz
Benefits to Whole Family
- Lobban and Barrowclough found family therapy lessens the negative effects of Sz on the family members and improves support
what is Token Economies in Sz?
rewards systems used to manage the behaviour of those with Sz who have adopted maladaptive behaviour from prolonged time in psychiatric hospitals
Tokens provide an immediate reward for target behaviour
- important because delayed rewards are less effective
how do Token Economies work in Sz?
Ayllon and Azrin
- token economy in ward full of women
- every time patients carried out a task such as making their bed or cleaning up they were given a token
- these token could be swapped for ward privileges
- the number of tasks done Increased Significantly
What is the Rationale for Token Economies?
people in institutions often develop bad habits (e.g. bad hygeine)
Matson developed 3 catagories of institution behaviour countered by token economies
- personal care
- condition-related behaviour
- social behaviour
what are the benefits of token economies of behaviour in institution?
- Improves person’s quality of life within hospital setting
- normalises behaviour for those who have spent a long time in hospitals to adapt back to normal life (e.g. getting dressed)
what is the Theoretical understanding of Token Economies?
The tokens are a Secondary Reinforcer in Behaviour Modification
- The Primary Reinforcers are the Meaningful Rewards
strength of Token Economies
Evidence of Effectiveness
- Glowaki et al identified 7 studies that examined token economies for people with chronic mental health issues
- all the studies showed a decrease in negative symptoms and reduced frequency of unwanted behaviours
Limitations of Token Economies
Ethical Issues
- gives professionals power over the patients behaviours - problem of imposing one persons norms onto others
- restricting the pleasures of distressed and ill people may make it worse
Other Approaches
- Chiang concluded Art Therapy may be a good alternative
- is a high-gain low-risk approach
- recommended by NICE guidelines
What is the interactionist approach in Schizophrenia?
the combination of Biological and Psychological factors causing Sz
- Biological - genetic vulnerability, neurochemical abnormality and neurological abnormality
- Psychological - Stress (e.g. life events or family dysfunction)
What is Meehl’s diathesis stress model in Schizophrenia?
- diathesis (vulnerability) was due to a ‘Schizogene’ - a characteristic of this is vulnerability to stress
- chronic stress through childhood and adolescence (especially Schizophrenogenic mother) leads to Sz
What is the modern understanding of Diathesis in Schizophrenia?
- multiple genes contribute to Sz not just the one ‘Schizogene’
- There are more factors affecting Diathesis than just genetics (such as psychological trauma)
- Read et al said childhood trauma can affect brain development (E.g. HPA system becomes hyperactive causing vulnerability to stress)
What is the modern understanding of Stress in Schizophrenia?
- Stress is now anything that could trigger Sz
- an Example of this is Cannabis use as it has been said to increase risk of Sz by up to 7x (due to interfering with dopamine receptors)
What is Treatment for Schizophrenia in the Interactionist Model?
Combining the use of Antipsychotics and CBT
- this is standard practice in Britain
- The use of just medication is more common in the US
Strengths for Interactionist approach to Schizophrenia
Support for Vulnerabilities and Triggers
- Tienari et al followed 19,000 Finnish children whose biological mothers were diagnosed with Sz
- This high genetic risk group were compared to adoptees with low genetic risk
- Adoptive parents were assessed for Child-rearing styles and found that high criticism, hostility and low empathy resulted in Schizophrenia in the high genetic risk group
Real World Application
- Tarrier et al randomly allocated Sz people to 1) Medication + CBT, 2) Medication and Counselling, 3) Medication Only
- The participants in the combination groups showed lower symptoms than the just medication group
Limitations of Interactionist approach to Schizophrenia
Oversimplication
- Meehl’s model only has one ‘Schizogene’ as a predisposed vulnerability
- We know this is not true
- Oversimplification of causes of Sz undermines its usefulness as an explanation
