Schizophrenia

paper 3

classification methods of schizophrenia

international classifications of disease (ICD-10)

diagnostic and statistical manual (DSM-5)

→ dropped inconsistent subtypes and no 1 defining characteristic

stats about schizophrenia

1% of population

25% improve after one episode

50-65% improve but have relapses

remainder have persistent difficulties

positive symptoms of schizophrenia

• hallucinations

• delusions

additional experiences beyond ordinary experience

hallucinations: auditory and visual involving distorted perception e.g. unusual sensory experiences like hearing voices that are not there or seeing, smelling, tasting.

delusions: irrational beliefs that make sense to them but are bizarre to others.

• paranoid delusions: someone/something deliberately trying to mislead, manipulate or hurt them

• delusions of grandeur: individual beliefs with some imaginary power or authority e.g. can fly, secret agent

negative symptoms of schizophrenia

• speech poverty

• avolition

loss of usual abilities and experiences

speech poverty: reduction in amount and quality of speech including delay or incoherent responses

avolition: finding it difficult to begin or do an activty with a goal due to lack of motivation e.g. lack of energy, persistence in education, poor hygiene and grooming

evaluating classification and diagnosis of schizophrenia

good reliability in the diagnosis of schizophrenia. classification systems have been updated helping different clinicians to reach the same diagnosis and same clinician on 2 occasions. DSM-5 pairs had inter-reliability of .97 and test rests of .92. common language leads to better understanding.

low validity- concern over assessing what we are trying to assess. cheniaux- 2 psychiatrists independently assess same 100 patients using both DSM and ICD-10.

1. 26 DSM + 44 ICD 2. 13 DSM +24 ICD

→ poor between classification systems and psychiatrists meaning schizophrenia may be under or over diagnosed.

comorbidity with other conditions. if other conditions occur together a lot of the time this questions the validity of their diagnosis as may actually be single condition. commonly diagnosed with other conditions like OCD, substance abuse so schizophrenia may not exist as a distinct condition.

has symptom overlap with other conditions e.g. both schizophrenia and bipolar have delusions and avolition meaning diagnosis is hard to distinguish and classification issues as may be variants of the same condition.

existence of gender bias. 1.4:1 men:women. may be women being less vulnerable genetically. likely women are underdiagnosed as function better due to closer relationships and more support. may not receive beneficial treatments.

existence of cultural bias. some symptoms e.g. hearing voices have different meanings in different cultures. british people of african Caribbean origin are up to 9% as likely to receive diagnosis as white british people, but not those in these countries so therefore not a genetic vulnerability. suggests validity of diagnosis is poor as confounded by cultural beliefs and behaviours or racial distrust of black patients.

family studies, schizophrenia

confirm that the risk of sz increases with genetic similarity to a relative with the disorder

GOTTESMAN

identical twins- 48%

siblings= 9%

cousins = 2%

• if both parents suffer, 46% chance of also developing

twin studies, sz

help researchers to work out whether nature or nurture has greatest influence

GOTTESMAN AND SHIELD: concordance rate for sz in mz twins =48% but 17% for dz twins

adoption studies, sz

prevalence when biological - 15%, when adopted- 2% (genetic connection)

mutation in genes, sz

due to radiation, poison and viral infection

fathers under 25: 0.7%

fathers over 50: 2%

increased risk of sperm mutation

candidate genes, sz

sz is polygenic as number of different genes involved

Ripke: compared genetics of 37,00 people with sz to 113,00 controls. found 108 separate genetic variations had slightly increased risk e.g. those coding for neurotransmitters like dopmane

aetiologically heterogeneous: different combinations of factors

diathesis stress model

genes/abnormality (creates the vulnerability) + stress (e.g. trauma, abuse) = disorder

neural correlates, the dopamine hypothesis

antipsychotics that reduce dopamine help to reduce symptoms

dopamine instrumental in regulating emotions and attention so having excess amounts may lead to problems with attention, perception and thought → cause sz

neurons that transmit dopamine firing too often or too easily are in high levels in subcortical areas- subcortical hyperdopaminergia- positive symptoms

cortical hypodopaminergia- abnormally low dopamine in prefrontal cortex- negative symptoms

→ high and low levels in different brain regions

evaluating neural correlates, the dopamine hypothesis

evidence for dopamine as antipsychotic drugs that reduce dopamine also reduce the intensity of symptoms. shows dopamine is involved in symptoms of schizophrenia

other neurotransmitters like glutamate found in post-mortem and live scanning studies of people with sz, and candidate genes also involved in glutamate production or processing. dopamine hypothesis overly simplistic as there are other neurotransmitters.

→ post mortems and PET scans found higher than normal levels of D2 receptors in brains of sz

→ cause and effect cannot be established as may be predisposing sz or onset of symptoms causing changes

evaluating genetic biological explanations for sz

monozygotic twins share 100% genetics and there are higher concordance rates between mz than dz showing a genetic cause

→ but concordance rates not 100% which we would expect if causation was completely genetic therefore may be due to environmental factors.

→ although 7/12 twins raised apart were concordant for sz

lack of population validity as samples were small in number and twins not representative of population so lacks generalisability

adoption studies separate out the effects of environmental and genetic factors. higher concordance rates between biological parents and children given away showing genetic link. risk of sz now increased among couples who adopted sz so environment factors not as significant.

research shows diathesis stress model due to environmental factors. genetic risk of sz increased significantly by communication deviance, birth complications, childhood trauma, smoking cannabis. but genetic factors not complete explanation (but less deterministic)

if genetic there should be able to be a gene that is linked to the development of the disorder yet no gene identified.

methodological explanations with research from Gottesman. may have been biased by knowledge of other family members who may have been diagnosed as not blind diagnosis.

→ reductionist in attempting to explain complex multi-faced disorder at levels of cells, genes and chemicals.

Typical antipsychotics (how they work, Kapur)

dopamine antagonists: reduce the amount of dopamine by blocking dopamine receptors in the synapses of the brain so reduce the action of dopamine.

Kapur: 60-75% of dopamine receptors have to be blocked for drugs to be effective meaning too many get blocked leading to side effects

eliminates hallucinations and delusions (positive symptoms)

chlorpromazine, example of typical antipsychotic

tablets (up to 1000mg), syrup or injection although initially doses are much smaller

also an effective sedative used to calm individuals especially when they are first admitted to hospital and anxious.

atypical antipsychotics (how they work)

aim to suppress both positive and negative symptoms of psychosis

block serotonin receptors as well as dopamine receptors

have fewer side effects because they don’t permanently block the dopamine action but bind only temporarily then rapidly dissociate

clozapine and risperidone, atypical antipsychotics

clozapine: withdrawn for a while due to deaths of some patients from blood condition called agranulocytosis. more effective than typical antipsychotics so used along with regular blood test. (typical dosage 300-450mg)

• acting on serotonin and glutamate helps improve mood, reduce depression and anxiety- prescribed especially for suicidal patients.

risperidone: tablets, syrups, injection (up to 12mg). binds more to dopamine receptors so effective in smaller doses leading to fewer side effects.

evaluating drug therapy

evidence to support effectiveness of typical and atypical antipsychotics in tackling symptoms.

• THORNLEY: reviewed studies comparing effects of chlorpromazine to control conditions. data from 13 trials with 1121 participants showed association with better overall functioning and reduce symptom severity as compared to placebo.

• MELTZER: clozapine more effective in 40% of cases where typical antipsychotics have failed

→ serious flaws with this effectiveness as most studies are of short term effects only and data published multiple times exaggerating the positive effects. may not actually reduce severity of psychosis just have powerful calming effects making it easier for staff not people themselves.

likelihood of side effects. typical antipsychotics lead to dizziness, agitation, sleepiness, stiff jaw, weight gain, itchy skin.

• tardive dyskinesia: involuntary facial movements like grimacing, blinking, lip smacking.

• neuroleptic malignant syndrome: when drug blocks dopamine action of the hypothalamus which regulates body leading to high temperature, delirium and coma which can be fatal.

• sufferers may be liable to relapse when drugs discontinued or become too dependent.

• 50% stop taking them in 1st year

do not understand why some antipsychotics work. strongly related to the dopamine hypothesis (high levels of dopamine lead to symptoms) not a complete explanation for schizophrenia as dopamine levels can be also too low which would not be effected by antipsychotics so not understood why some work. may not be best treatment, also focused on treating symptoms not cause.

Family dysfunction, schizophrenogenic mother (bit of AO3)

Fromm Reichman

• cold, rejecting and controlling creating a family climate characterised by tension and secrecy

• distrust → schizophrenia (paranoid delusions)

lack of control group

many with sz don’t have these mothers

Family dysfunction, Double bind theory

• emphasises role of communication style

• developing child regularly finds themselves in situations where they fear doing the wrong thing but receive mixed messages about what is and feel unable to get clarification.

• ‘get it wrong’ often leading to withdrawal of love so understand world as confusing and dangerous reflected in symptoms like disorganised thinking and paranoid delusions (risk factor)

family dysfunction, expressed emotion

particularly negative expressed emotion can lead to relapse and onset (part of diathesis stress model)

verbal criticism, hostility, emotional overinvolvement → violence, anger, rejection becomes a serious source of stress for those with schizophrenia

cognitive explanations, dysfunctional thinking

• sz characterised by disruption to normal thought processing

• evidence of reduced thought processing in ventral striatum, temporal and angulate gyri

cognitive explanations, meta representations

• ability to reflect on behaviour and thoughts allows insight into intentions and goals and interpret other’s actions.

• dysfunction means recognise own thoughts and actions as being carried out by someone else. own thoughts are attributed to outside world, actually just hearing inner speech but symptom of hallucination

cognitive explanations, central control

• issues with cognitive ability to suppress automatic responses

• e.g. experience derailment of thoughts as each word triggers associations and person cannot sppress automatic responses

Evaluating psychological explanations for sz

evidence linking family dysfunction to sz

• READ: adults with Sz are disproportionately likely to have insecure attachment and exposure to childhood trauma e.g. abuse
  - 69% of women and 59% of men with sz have a history of abuse

• family dysfunction makes people more vulnerable to sz

Brown: people recovering from sz and discharged from hospital followed up in 9 month period.

• families with high EE levels → 58% people relapsed (only 10% for lower level families)

Poor evidence base for schizophrenogenic mother and double blind. Based on clinical observation and informal assessment which are open to interpretation rather than systematic evidence. Also highly socially sensitive because it can lead to parent blaming (especially mothers) who already have to care for child and watch them suffer, blaming is not helpful.

Evidence for dysfunctional thought processing. Stirling: compared performance on range of cognitive tak in 30 sz Ps and 30 controls. e.g. Stroop- Ps name font colours of colour words so suppress tendency to read words aloud. Those with sz on average take 2x as long showing cognitive processes are impaired

only explains what is happening now (proximal) to produce symptoms rather than explaining initial causes (distal). does not further understanding of why problems with cognitive abilities are caused, so only a partial explanation.

cognitive behaviour therapy for sz

• duration

• aim

• ways of challenging

takes place over a period of 5-20 sessions

Helps to make sense of the impact of irrational cognitions on feelings and behaviours (and tackle resulting anxiety and depression)

Challenges the evidence of delusions: so know they cannot be hurt reducing feelings of distress therefore increasing function.

1. explaining biological processes e.g. hearing voices is a result of malfunctioning speech centre

2. normalises symptoms e.g. ordinary experience of thinking just heard

3. reality testing: jointly examine the likelihood that beliefs are true through designing arguments to test experiences.

example of reality testing

client: the mafia are observing me to decide how to kill me

therapist: you are obviously very frightened… there must be a good reason for this.

client: do you think it is the mafia

therapist: it’s a possibility but there could be other explanations. how do you know it is the mafia?

evaluating cbt for sz

evidence for effectiveness

JAUHAR: reviewed 34 studies of using CBT with sz concluding that there is clear evidence for small but significant effects on both positive and negative symptoms.

PONTILLO: reductions in frequency and severity of auditory hallucinations.

→ NICE recommends CBT for SZ

There is a wide range of techniques and symptoms included in studies so techniques and symptoms vary so much. Therefore a wide variety of effects of different techniques on different symptoms so hard to say how effective CBT would be for a particular person with Sz.

challenging paranoia may begin to interfere with individuals’ freedom of thought leading to ethical issues.

family therapies

• negative symptoms

• ability to help

• benefits

takes place with families as well as patient aiming to improve communication and interactions between family members.

negative symptoms: reduce levels of expressed emotions such as negative emotions like anger and guilt which lead to stress. therefore reduce the chance of relapsing.

improve the family’s ability to help: encourages family members to all agree on aims of the therapy and to improve families’ beliefs about and behaviour towards sz. achieve a balance between caring for the individual and maintaining their own lives.

→ warmer atmosphere → ability to anticipate and solve problems → better progress

model of practice, Burbach (family therapies)

1. sharing information and providing emotional and practical support

2. identifying resources/ what the family can offer

3. encourage mutual understanding, create a safe space for everyone to express feelings.

4. identify unhelpful patterns of interactions

5. skills training, stress management techniques

6. relapse prevention training

7. maintenance for the future

evaluating family therapies

evidence for effectiveness

• McFarlane concluded that family therapy was one of the most consistently effective treatments.
  - 50-60% reduction in relapse rates

• Pharaoh: also improved quality of life for patients and families

→ NICE recommends for all who have a diagnosis.

Benefits for all family members. Lobbam and Barrowclough: concluded that this is important as families provide the bulk of care. strengthening the function of a family lessens the negative impact of sz and strengthens ability to support as a family.

token economy systems- managing sz

• purpose

• method

• 3 aims

• results

manage behaviour of sz, particularly those who have developed maladaptive behaviour through long periods in hospitals.

Allyon and Azrin: trialled a token economy system in a ward of women with a diagnosis of sz. identify appropriate target behaviours using primary and secondary reinforcers. (operant conditioning)

making bet, cleaning up → token → film

institutionalisation: due to prolonger hospitalisation led to bad habits e.g. lack of good hygiene, lack of socialising with adults

• personal care

• condition related behaviours e.g. apathy

• social behaviours

→ improves quality of life within setting

→ normalises behaviour so that people can adapt to life outside hospital in the community.

evaluating token economy systems and sz

evidence for their effectiveness, GLOWACKI

• identified 7 high quality studies that examined the effectiveness of token economies for those with mental health issues like sz

• all the studies showed a reduction in unwanted behaviours

→ small evidence base to support the effectiveness of a technique. file drawer problem- bias towards positive, published findings as undesirable results are filed away questions the evidence of effectiveness.

ethical issues: gives professionals considerable power to control the behaviour of people in the role of patient. e.g. curtailing personal freedoms as just imposes institutions norms. restricting the availability of pleasures like going outside, watching a film to people who do not behave as desired. means seriously ill people who already are distressed have worse time.

there exists more pleasant and ethical alternatives.

• other approaches with a comparable evidence base that do not raise the same ethical issues.

• Chiang, art therapy: evidence is limited but shows art therapy has a high gain low risk approach to managing sz → recommended by NICE.

difficult to continue outside a hospital setting as target behaviours cannot be monitored closely and tokens cannot be administered immediately- not how the real world works.

Diathesis stress model, interactionist approach

Diathesis (one or more vulnerabilities) + stress (a negative experience which acts as a trigger) leads to schizophrenia

Meehl’s original diathesis stress model

diathesis: this vulnerability was entirely genetic from one schizogene which led to a schizotypic personality.

stress: usually childhood stress like a schizogenophrenic mother which would then trigger sz

without the gene no amount of stress would lead to sz

Diathesis (modern understanding)

• sz is polygenic so there are lots of genes which increase vulnerability

• diathesis is also not just genetic e.g. a psychological trauma may make you more vulnerable

READ: early trauma alters the developing brain. severe enough trauma like child abuse can affect the hypothalamic-pituitary-adrenal system (fight or flight) leading to a vulnerability.

stress (modern understanding)

anything that risks triggering sz

e.g. psychological stress from a parenting style. cannabis (increases risk 7x as interferes with the dopamine system).

Interactionist approach- therapies

Based off the modern diathesis stress model, a combination of biological and psychological treatments are used and are standard practice in the UK.

evaluating the interactionist approach

evidence supporting the role of both vulnerability and triggers, TIERANI

• followed 19,00 Finnish children whose biological mothers had been diagnosed with sz

• this high genetic risk group was compared with a control group of adoptees who did not have a family history of sz

• parents were assessed for child rearing styles (e.g. high levels of criticism, hostility and low levels of empathy)

• only children who received this and were in the high genetic risk group developed sz showing the combination increases risk.

combination of biological and psychological treatments was effective TARRIER

• randomly allocated 315 Ps to:

1. medication and CBT

2. medication and counselling

3. control: medication

• ps in 2 combination groups showed lower symptom levels though no difference in hospital readmission

• clear practical advantage in adopting an interactionist approach in terms of treatment outcomes.

the original diathesis stress model is oversimple.

• too simplistic to say schizogene and schizogenophrenic mother lead to sz

• stress comes in many forms and sz is also polygenic, and the diathesis can be psychological

HOUSTON: childhood sexual abuse (underlying vulnerability) and cannabis (trigger)

supports the modern understanding of diathesis and stress.