Schizophrenia Flashcards
What are the two classification systems of schizophrenia and how do they differ ?
ICD 10
DSM 5
DSM 5 says one positive symptom must be present
ICD 10 two or more negative symptoms must be present
What are negative symptoms of schizophrenia?
Loss of usual abilities and experiences
- Avolition = Severe loss of motivation
- Speech poverty = Reduction in the amount and quality of speech
eg DSM emphasises speech disorganasation and poverty
What are the positive symptoms?
Additional experiences beyond those of ordinary existence
- Hallucinations - sensory experiences that have no basis in reality or distorted perceptions of real things
eg seeing people that are not there - Delusions - beliefs that have no basis in reality
eg conspiracies
What are the issues with diagnosis?
- Reliability - the extent to which the diagnosis of schizophrenia is consistent
- Validity - the extent to which diagnosis measure what they set out to measure
- Co Morbidity - occurence of 2 illnesses together which confuses diagnosis and treatment
- Symptom overlap - 2 or more conditions share symptoms, questioning the validity
A03 EVALUATION - diagnosis and classification of schizophrenia
LIMITATION - Diagnosis has low reliability
- poor interater reliability eg 1 psychiatrist diagnoses 26 using DSM and 44 using ICD/// 2nd psychiatrists diagnosed 13 with DSM and 24 with ICD
LIMITATION - Co morbidity
- buckley found 1/2 of patients also have a diagnosis of depression (50%) or substance abuse (47%)
LIMITATION - gender bias
- women are able to escape diagnosis
LIMITATION - cultural bias
- abnormalities eg hearing voices
What is the biological explanation of SZ?
- SZ runs in families
—–> genetic similarity of of family members and likelihood of both developing schizophrenia
—–> MZ twins have 48% shared risks
—–> Schizophrenia is polygenetic = each individual gene confers a small increased risk of SZ
—–>Schizophrenia is aetiologically heterogenous = different combos can lead to SZ - Dopamine Hypothesis
—–> Dopamine is involved as it is featured in the functioning of brain symptoms
—–> Hyperdopaminergia : High DA activity in subcortex associated with hallucinations and poverty of speech (excess of dopamine receptors in brocas areas)
—–> Hypodopaminergia : Low DA activity in prefrontal cortex (thinking and decision making) - Neural correlates
—–> Measurements of the structure or function of the brain that correlate with (+/-ve) symptoms
—–> Ventral striatum involved in anticipation of reward (avolition)
—–> Juckel found a negative correlation between ventral striatum and negative symptoms
—–> Allen found that patients experiencing auditory hallucinations recorded lower activation levels in the superior temporal gyrus
A03 - biological explanation of SZ?
STRENGTH - Strong evidence for genetic vulnerability
- Adoption studies show children of SZ are still at heightened risk if adopted into families without
STRENGTH - role of mutation supports genetic explanation
- sz can take place in the absence of family history of disorder (mutation of paternal dna in sperm cells)
- increased risks between paternal age and sz (0.7% in dads under 25 and 2% in fathers over 50)
LIMITATION - clear that the environment is also involved
- probability of developing SZ even if identical twin has it is less that 50%
- evidence that ebvironmental factors can also play a role
- biological and physiological approaches
LIMITATION - mixed support for dopamine hypothesis
- dopamine antogonists that increase DA can induce sz symtoms in people without
- antipsychotics can lower dopamine can also reduce symptoms
- some of the candidate genes identiifed code for the production of neurotransmitters such as glutamate
- this suggests that DA cannot provide a complete explanation for SZ
What are the psychological explanations of SZ?
- Family dsyfunction
—> Reichmans psychodynamic explanations based on patients early experiences of schizophregenic mothers (mothers who cause schizophrenia - rejecting, controlling, create a family climate of tension and secrecy —> paranoid delusions)
—> Double bind theory = Bateson described how a child may be regularly trapped in situations where they get conflicting messages about what is wrong so they fear doing wrong. They cannot express their feelings.
= When they get it wrong the child is punished with withdrawal of love - learn the world is confusing which leads to delusions
—> Expressed emotion is the level of emotion expressed towards sz patients (verbal criticism, hostility, emotional over involevement) this leads to relapse
- Cognitive explanations
—> Dysfunctional thought processing = low levels of information processing in some areas of brain suggests cognition is impaired eg reduced processing in ventral striatum associated with (-ve symptoms)
—> Metarepresentation = the cognitive ability to reflect on thoughts and behaviour which distrupts our ability to recognise our own which leads to (+ve) symptoms
—> Dysfunction of central control leads to speech poverty = central control being the cognitive ability to suppress automatic responses while performing deliberate actions = people with sz experience derailment of thoughts and spoken sentences becuase each word troggers automatic responses they cannot suppress
A03 evaluation - psychological explanations of sz?
LIMITATION - Evidence for family relationships is poor
—> Although there is plenty of evidence supporting the idea that childhood family based stress can cause SZ there is no support on theories such as schizophregenic mother and double bind
—> These theories are based on clinical observation and infromal assessment of mothers peronsality but not systematic evidence
—> Family explanations have not been able to account for the link between childhood trauma and SZ
STRENGTH - Support for different information processing
- Stirling et Al compared 30 patients with SZ to 18 w/out (control) on cognitive tasks (stroop tests (colour different to word eg purple)
- Patients took longer to surpress impulse to read word and name ink instead
- Supports friths theory of central control dysfunction
- HOWEVER it is not clear whether these faulty cognitions are the proximal cause (cause of symptom) or distal cause (origins)
LIMITATION - Evidence for family relationships is retrospective
- Read at al reviewed 42 studies and concluded 69% of all female inpatients and 59% men with SZ had history of physical/sexual abuse in childhood
- Evidence is based on information about childhood experiences but the symptoms may have distorted the patients recall of their childhood experiences
LIMITATION - Biological factors overlooked
- Psychological explanations can be hard to reconcile with biological ones
- If the biological ones are valid how do they fit with psychological ones?
- Both psych and biological factors can separately produce seperate symptoms - are both outcomes sz
- View as diathesis stress model where diathesis be biological or psychological
BIOLOGICAL THERAPIES (drugs) - What is atypical antipsychotics?
—> Target dopamine and serotonin eg CLOZAPINE
—> The drugs are used to improve effevtiveness of drigs in surpressing psychoses of sz and reduce side effects
—> CLOZAPINE acts on dopamine, glutamate and serotonin to improve mood
—> Reduces depression, anxiety and improves cognitive functioning
—> 300-450 mg
—> RISPERIDONE binds to dopamine and serotonin
—> Developed because clozapine was involved in deaths of some patients from a blood condition
—> Risperidone binds more strongly so more effective in smaller doses and smaller side effects
—> Tablet, syrup or injection
—> 4-8mg max of 12 mg
BIOLOGICAL THERAPIES (drugs) - What is typical antipsychotics?
> > > > Dopamine antogonists
—> reduce action of dopamine by working as antagonists
—> block dopamine receptors in the synapses of the brain reducing action of dopamine
—> dopamine levels build up after taking CHLORPROMAZINE but then production is reduced, which normalises neurotransmission in key areas of the brain which reduces symptoms
—-> CHLORPROMAZINE has an effect on histamine receptors which leads to sedation effect
A03 EVAL BIOLOGICAL THERAPIES
STRENGTH - Antipsychotics are moderately effective
—> Thornley reviewed data from 13 trials and found CHLORPROMAZINE was associated with better functioning and reduced symptom severity compared with placebo
—> Support for atypical antipsychotics
—> Meltzer concluded clozapine is more effective then typical antipsychotics and that it is 30-50% more effective in treatment resistant cases
LIMITATION - Antipsychotics side effects
—>dizziness, agitation, sleepiness, weight gain and long term would lead to lip smacking due to dopamine super sensitivity
—> most serious side effect is NMS caused by blocking dopamine action in hypothalamus (disrupts regulation of several body systems)
—> can put people off
LIMITATION - Doubts about true effectiveness of antipsychotics
—> data have been published multiple times exaggerating the positive effects
—> most studies only review short term effects
—> antipsychotics have powerful calming effects but may not actually reduce psychosis
—> effectiveness may be overestimated by empirical reserach
What are the the Psychological therapies ?
CBT
> This is where they help patients identify irrational thoughts and try to change them
> Patients are helped to make sense of how theur delusions and hallucinations impact on feelings and behaviour
> Helps to reduce anxiety and helps patients belief are not based on reality
Family Therapy
> improve communcation and interaction
> reduce stress and ee to ensure no relapse
> Strategies used :
1. reduce stress of caring for a relative
2. Improve ability to anticipate and solve problems
3. Reduce guilt and anger
4. Improve beliefs and behaviour towards SZ
Token Economies
> Reward systems (operant conditioning) in order to carry out desirable behaviours
> Patients need to make bed or get dressed etc to get a token
> Reinforces behaviour and reduces effect of delayed rewards
> Tokens can be swapped for sweets, a walk outside etc
> They are SECONDARY REINFORCERS becuase they only have value due to learned assocation (classical conditioning) with innate primary reinforcers
A03 EVAL psychological therapies
LIMITATION - limited benefits
- Significant but small effect on positive/negative symtoms
- One of three studies of token economies thta used random allocation showed improvement
- Pahroah reviewed effectiveness of family studies and found moderate eveidence for reduction of readmissions and some improvement to quality of life but evidence was inconsistent
LIMITATION - they help but not cure
- CBT helps them make sense of symptoms
- Family therapy reduces stress
- token economies make the behaviuor more acceptable
LIMITATION - ethical issues
- Token economies arent used with severely ill patients as they are less likely to comply with desirable behaviours
- Severyly ill patients suffer discrimnation
- CBT can challenge paranoia but also interfere woth freedom of thought
LIMITATION - alterntaives under researched
- art theroay to help those iwth sz
- not well researched so not effective
- questions the validity
What is the interactionist approach?
- The diathesis stress model
- vulnerability and stress trigger needed to develop sz - Meehls model
- the schizogene is necessary but not sufficent for development of SZ
- the gene makes them vulnerable to effects of chronic stress - Modern understanding of diatehsis
- sz due to many genes that increase vulnerability
- diathesis could not just be genetic but also things like pschologivcal trauma affecting brain development eg child abuse - Modern understanding of stress
- anything that risks triggering SZ
- eg cannabis can increase the risk upto 7 times as it interferes with dopamine system
What is the treatment according to interactionist approach?
- Antipsychotics and CBT
- cbt to relieve symptoms
- this requires an interactionst approach eg not purely due to bioligy - UK adopts more interactionst compared to US
- standard practice in uk to treat with drigs and cbt
- us there is conflict between psychological and biological models of sz and this led to slower adoption of interactionst
AO3 EVAL FOR INTERACTIONST APPROACH
STRENGTH - support for dual role of vulnerability and stress
- tienari et al studied adopted children away from sz mother and the parenting styles of adoptive parents were conpared with a control group woth no genetic risk
- high levels of criticism and comflict and low levels of empathy was implicated in development of sz bit only for children with high genetic risk
-strong support for interactionst approach - genetics and family stress combine in development
STRENGTH - usefulness of interactionst in treatment
- tarrier et al randomly allocated 315 patients to medication + cbt, medication + supportive counselling , control
- patients in the combo groups show lower symptoms that the control (only meds) but no difference in readmission in hospital
- clear advantage to adopting interactionst approach
LIMITATION - treatment causation fallacy
- combining biological and psychological therapies are more effective then either on its own does not mean the interactionist approach is correct
- the fact that drugs help does not mean that SZ is biological in origin - treatment causation fallacy
- superior outcomes of combined therapies should not be over interpreted in terms of evidence in support of interactionst
what is the management of sz?
token economies
what categories does token economies tackle?
personal care
condition related behaviour
social behaviour
what are the 2 main benefits of tackling those categories?
longer quality of life
normalisation
how does token economies work?
when a target behaviour is reached, token economies switch them out for a tangible reward
what conditioning does token economies use and why?
operant
secondary reinforcers
primary recinforces -rewards
a03 token economy
- evidence for effectiveness
–> reduced negative symptoms and unwanted behaviours
–> sample of 7 studies
COUNTER
–> 7 is too small - file drawer problem where undesirable rewards are filed away - ethical issues
–> professionals have power
–> imposing norms onto others
–> restricting behaviours to those less ill - alternatives
–> art therapy
–> high gain low risk
–> nice guidelines recommend
