Schizophrenia

define schizophrenia

define schizophrenia

severe mental illness where contact with reality and insight are impaired

• effects about 1% of the population

• more commonly diagnosed in men than women

• higher diagnosis rates in urban areas

• more common in WC than MC

define ‘positive symptom’

atypical symptoms experienced in addition to normal experiences.

define ‘negative symptom’

atypical symptoms that represent the loss of a usual experience.

what are the positive symptoms of schizophrenia?

• hallucinations

• delusions

what are the negative symptoms of schizophrenia?

• avolition

• speech poverty

define hallucinations as a positive symptoms of schizophrenia

unusual sensory experiences with no basis in reality - can be experienced through any sense

define delusions as a positive symptom of schizophrenia

beliefs that have no basis in reality - often experienced as paranoia and can take a range of forms

define avolition as a negative symptom of schizophrenia

loss of motivation to carry out tasks - apathy

Andreason (1982) -

• poor hygiene

• lack of persistence in work or education

• lack of energy

define speech poverty as a ‘negative symptom’ of schizophrenia

changes in patterns of speech

reduction in both amount and quality of speech

also characterised by disorganisation in which speech becomes incoherent

list issues in diagnosis and classification of schizophrenia

• different definitions of symptoms (+ve vs -ve)

• different diagnostic tools - ICD(11) vs DSM(5)

• interrater reliability

• co-morbidity

• symptom overlap

• gender and cultural bias in diagnosis

outline the problems caused by different diagnosis tools for the consistent diagnosis of schizophrenia

• ICD(11) recognises different subtypes of schizophrenia - more than DSM(5)

  • may not receive a diagnosis that you otherwise would’ve if you lived somewhere else

• ICD(11) will diagnose if you only have -ve or +ve symptoms but DSM(5) requires both +ve and -ve

outline the problem of interrater reliability in the diagnosis of scz

Cheniaux - two psychiatrists independently diagnosed 100 patients using both DSM and ICD characteristic

• interrater reliability was v low

  • one diagnosed 26 according to DSM and 44 according to ICD

  • one diagnosed 13 according to DSM and 24 according to ICD

• likelihood of receiving a scz diagnosis = partially dependent on who is diagnosing you

outline the issue of co-morbidity and symptom overlap in diagnosing scz

two or more conditions occur together

• this can call into question the validity of their diagnosis

• Peter Buckley (2009)

  • 50% of patients w a scz diagnosis also have depression

  • 29% comorbid w PTSD

  • 23% comorbid w OCD

• maybe we’re just bad at telling the difference between the two conditions

• considerable symptom overlap between scz and other mental illnesses like bipolar disorder

  • diagnosis becomes confusing and less valid

outline the issue of gender bias in diagnosing scz

• men are consistently diagnosed more

  • this could simply be because they’re more genetically vulnerable

  • or could be gender bias

• Cotton et al (2009) - female patients function better than men

  • more likely to work and have good relationships

  • symptoms are either completely masked or appear not to be severe enough to warrant a diagnosis

outline the issue of cultural bias in diagnosing scz

• diagnosis rates are highest among African-Americans and British people of Afro-Caribbean origin

  • this is not paralleled by particularly high rates of scz in Africa

• explanations could be:

  • +ve symptoms - hearing voices - are more accepted in African cultures, potentially thought of as communication w ancestors

    • psychiatrists in the Western world interpret this differently

  • Escobar (2012) - white psychiatrists tend to overinterpret symptoms and distrust the honesty of black people during diagnosis.

three biological explanations for schizophrenia

• genetic basis

• dopamine hypothesis

• neural correlates

outline the genetic basis of scz

• runs in families - supported by Gottesman’s research

• the closer the genetic similarity to a relative w scz, the more likely an individual is to also have scz

• candidate genes - individual genes believed to be associated with risk of inheritance

  • polygenic

  • aetiologically heterogenous

outline the dopamine hypothesis

• brains chemical messengers appear to work differently in scz patients

  • in particular, dopamine is believed to be involved

• hyperdopaminergia in the subcortex- high levels of dopamine, may be associated w poverty of speech and/or auditory hallucinations

• hypodopaminergia in the cortex - abnormal levels in cortex

  • low levels have possible role in negative symptoms of scz

outline neural correlates as a biological explanation for scz

• patterns of structure or activity in the brain that occur in conjunction with an experience and may be implicated in its origins

• neural correlates for positive symptoms -

  • Allen (2007) - low activation levels in superior temporal gyrus and anterior cingulate gyrus = higher likelihood of experiencing hallucinations

• neural correlates for negative symptoms -

  • Juckel (2006) - abnormality in ventral striatum believed to be involved in the development of avolition

give three weaknesses of biological explanations for schizophrenia

• research is mostly correlational - calls into question the validity of the assumption that these factors are causative

  • it may not be that ventral striatum damage causes -ve symptoms but that -ve symptoms or another factor cause ventral striatum damage

• role of environment - MZ twins in Gottesman’s study did not share 100% inheritance of scz despite sharing 100% of their genes - DZ twins have higher rates than siblings despite sharing the same amount of DNA -environment must have some role

• scz can occur without a family history of it - mutation.

list the psychological explanations for scz

• family dysfunction/family systems theory

  • schizophrenogenic mother

  • double-bind theory

  • expressed emotion

• cognitive explanations

  • dysfunctional thought processing

    • central control

    • metarepresentation

outline the schizophrenogenic mother as a psychological explanation of scz

• Fromm-Reichman (1948)

• interviewed patient of scz about their childhoods

• found that many of them spoke of a particular type of parent - the schizophrenogenic mother

  • cold and rejecting

  • controlling

  • creates a family climate characterised by tension and secrecy

• leads to distrust that later develops into paranoid delusions

outline double-bind theory as a psychological explanation of scz

• Bateson (1972)

• family climate is important - emphasises the role of communication

• developing child finds themselves in situations where they fear doing the wrong thing but receive mixed messages as to what the wrong thing is

• when they get it wrong - the child is punished by withdrawal of love :(

• leaves the child with an understanding of the world as confusing and dangerous

  • leads to symptoms like disorganised thinking and paranoid delusions

• not a main cause - just a risk factor

outline expressed emotion as a psychological explanation of scz

• level of emotion expressed towards a patient by their carers

• consists of 3 elements

  • verbal criticism of the patient - sometimes accompanied by violence

  • hostility towards the patient - anger and rejection

  • emotional over-involvement in the life of the patient - including needless self-sacrifice

• these are a serious source of stress for the patient

  • primarily an explanation for relapse

  • has been suggested it could trigger the onset of scz in someone who is already genetically vulnerable

outline the cognitive psychological explanations for scz

• Frith (1992) - dysfunctional thought processing

  • meta representation - cognitive ability to reflect on thoughts and behaviour. This allows us insight into our own intentions and goals.

    • dysfunction = inability to recognise our own actions as being carried out by ourselves - can explain hallucinations of voices and delusions like thought insertion

  • central control - ability to supress automatic responses and perform deliberate actions instead

    • dysfunction could lead to symptoms like disorganised speech and thought disorder

give three weaknesses of psychological explanations for schizophrenia

• socially sensitive - blame parents for condition, especially mothers

• correlation does not equal causation

• evidence for biological factors not adequately considered

what’s the biological treatment for scz?

drug therapy - antipsychotics

define antipsychotic

drugs used to reduce the intensity of symptoms, in particular, the positive ones of psychotic conditions like schizophrenia

define typical antipsychotic and give an example

first generation antipsychotics - used since 1950s, work as dopamine antagonists

Chlorpromazine

define atypical antipsychotic and give two examples

drugs for scz developed after typical antipsychs, target a range of neurotransmitters

Clozapine, Risperidone

outline the characteristics of Chlorpromazine and how it works

• typical

• taken as a tablet most often - can be an injection or syrup

• dopamine antagonist - decreases activity

  • blocks receptors

  • initially increases levels and then decreases

  • normalises neurotransmission - decreases symptoms like hallucination

• also has uses as a sedative - most effective at this in syrup form

outline the characteristics of Clozapine and how it works

• atypical

• has potentially fatal side effect in a blood disorder - therefore not available as an injection

• binds to dopamine receptors just like chlorpromazine but also targets other neurotransmitters - serotonin and glutamate

  • helps depression and anxiety too

• often prescribed for patients considered to have a high suicide risk

  • 30-50% of scz patients attempt suicide at least once

Outline the characteristics of risperidone and how it works

• typical antipsychotic

• developed in an attempt to produce a rug as effective as Clozapine but without the serious side effects

• can be taken as tablets, syrup, or injection

• starts as a low dose and is gradually increased

• works in same way as clozapine but binds to dopamine receptors even better

  • some evidence to suggest this leads to fewer side effects

give 1 strength and 3 weaknesses of the biological treatment for schizophrenia

• research support

  • typical - Thornley et al: reviewed studies comparing chlorpromazine to a placebo, comprised of 1121 participants. Found that chlorpromazine was associated with overall better functioning and relapse rate was lower

  • atypical - Meltzer: concludes that Clozapine is more effective than typical antipsychotics - effective in 30-50% of treatment resistant cases

• serious side effects

  • dizziness, agitation, sleepiness, weight gain, itchy skin …

  • tardive dyskinesia - caused by dopamine super sensitivity, grimacing, blinking, lip-smacking

  • neuroleptic malignant syndrome - blocks dopamine action in hypothalamus (associated with regulation of a number of body systems) - leads to serious, potentially fatal condition - delirium and coma

• chemical cosh argument

  • some believe they can be used to calm patients making them easier for staff to work with not for the patient’s benefit

  • this is recommended short term by the NICE but some view it as a human rights abuse

  • Germany has banned the use of them for ‘coercive treatment’

• theoretical issue of dopamine hypothesis - if the dopamine hypothesis doesn’t work then neither do antipsychotics

list the three types of psychological therapy for schizophrenia

• CBT

• Family therapy

• Token economies

outline the use of CBT to treat schizophrenia

• helps patients identify irrational thoughts

• doesn’t get rid of symptoms but better equips patients to cope with them

• patients can be helped to make sense of their delusions and hallucinations- giving psychological reasons for frightening experiences

• delusions can also be challenged so patient can learn that they aren’t based on reality

• Turkington et al - example

  • P - the mafia are observing me, deciding how to kill me

  • T - you are obviously frightened, there must be a good reason for this

  • P - do you think it’s the mafia?

  • T - it’s a possibility, but there could be other explanations. How do you know it’s the mafia?

outline the use of family therapy to treat schizophrenia

• improves the quality of communication and interaction between family members

• inline with family systems theory

• Pharoah et al - range of strategies by which family therapists aim to improve the functioning of a family with a schizophrenic member

  • therapeutic alliance with all members

  • reducing the stress of caring for an individual with schizophrenia

  • improving ability of family to anticipate and solve members

  • reduction of anger and guilt in family members

  • helping family member maintain caring/life balance

  • improving families beliefs about and behaviour towards schizophrenia

• these strategies work by reducing levels of stress and expressed emotion whilst increasing the chances of patients complying with medicine

• this = lower relapse rates and a lower likelihood of being re-admitted

outline the use of token economies to treat schizophrenia

• type of therapy based on behaviourist principle of operant conditioning

• reward systems use to manage the behaviour of scz patients who have developed maladaptive patterns of behaviour from spending extended periods of time in psychiatric hospital

  • development of bad hygiene

  • remaining in pyjamas all day

• doesn’t cure schizophrenia but improves patient’s quality of life

• tokens - often in form of coloured disks are given immediately to patients when they carry out a behaviour that has been targeted for behaviour - immediacy of reward prevents ‘delay discounting’ - the reduced effect of a delayed reward. secondary reinforcers

• rewards - tokens can be swapped for more tangible rewards, material or privilege

give three evaluation points for psychological treatments for schizophrenia

• evidence for effectiveness

  • CBT - Jauhar et al

    • reviewed results of 34 studies - CBT has a significant (but fairly small) effect on both positive and negative symptoms

  • Family therapy - Pharoah et al

    • reviewed evidence to support

    • was effective but findings over different studies were inconsistent

  • token economies - Sultana et al

    • found only 3 studies where participants were randomly allocated, only one of these 3 showed improvement in symptoms and none yielded useful information about behaviour change

• improve quality of life but do not cure

• alternative psychological treatments - like art therapy (recommended by NICE)

define the interactionist approach to schizophrenia

a broad approach to explaining schizophrenia, which acknowledges that a range of factors, including biological and psychological, are involved in the development of schizophrenia

outline the key arguments of the interactionist approach

• diathesis stress

  • Meehl’s model - diathesis = entirely genetic - if the person does not have the ‘schizogene’ then no amount of stress would lead to schizophrenia

  • Ripke: modern understanding of diathesis - there is no single ‘schizogene’, other things can serve as diathesis like psychological trauma

  • modern understandings of stress - stress was originally seen as solely psychological in nature but can now be considered to be anything that risks triggering scz

• treatment

  • combination of anti-psychotics and and psychological therapies like CBT

  • Turkington et al - it is perfectly possible to believe in biological causes, and still prescribe psychological treatment in order to decrease symptoms

  • increasingly standard practice in the UK

give two strengths and two weaknesses of the interactionist approach to explaining schizophrenia

• research support for effectiveness of combinations of treatments

  • Tarrier (2004) - 315 patients were randomly allocated to a medication + CBT group, a medication + supportive counselling group, or a control (medication only). Patients in the combination groups showed greater decrease in symptoms than those only being treated by medication

• research support for role of vulnerability and triggers

  • children adopted from 19,000 Finish mothers with schizophrenia compared to a control with no genetic risk

  • adoptive parents assessed for child rearing style

  • child rearing styles from adoptive parents characterised by high levels of criticism and conflict was implicated in the development of schizophrenia but only in the children that were already at a genetic predisposition to it

• original model over simple

  • but resolved by newer ideas

• treatment-causation fallacy

  • just because the treatments are more effective together than individually doesn’t mean the the interactionist approach is correct