Schizophrenia Flashcards
Diagnosis and classification of Schizophrenia AO1
collection of unrelated symptoms
DSM-5 one positive symptom must be present
ICD-10 two or more negative symptoms present
Positive symptoms - additional experiences
1. hallucinations - sensory experiences that are distorted perceptions of real things ie hearing voices
2. delusions - beliefs that have no basis in reality but to someone w scz ie being important
Negative symptoms - loss of usual experiences
1. avolition - loss of motivation to carry out everyday tasks
2. speech poverty - reduction in amount and quality of speech
Issues in diagnosis -
reliability - whether diagnosis is consistent
validity - whether the diagnosis measures what its designed to measure
comorbidity - two illnesses together confusing diagnosis
symptom overlap - two or more conditions sharing same symptom questions validity
Diagnosis and classification of Schizophrenia AO3
-low reliability - cheniaux et al had 2 psychiatrists independently diagnose 100 patients with dsm and icd, inter rater reliability poor - one diagnosed 26 with scz using dsm and 44 using icd and other diagnosed 13 with dsm and 24 w icd - inconsistency bw professionals and classification system
-low validity - criterion validity - do diff assessment systems arrive at same diagnosis for same patient - cheniaux et al shows more likely to diagnose using icd - scz overdiagnosed in icd or underdiagnosed in dsm - poor validity
-comorbidity - 2 illnesses together confusing diagnosis - buckley et al concluded half of patients with scz have depression or substance use - if very severe depression looks like scz vice versa it may be that it is a single condition causing confusion
-cultural bias - african americans more likely to be diagnosed with scz but rates in africa not so high so not genetic vulnerability - higher diagnosis rates in uk may be cos positive symptoms are culturally normal in africa ie hearing voices part of ancestor communication so issue in validity as ppl from diff cultures more likely to be diagnosed cos bias
Psychological explanations for schizophrenia AO1
Family dysfunction - schizophrenogenic mothers cold rejecting and controlling create tension and secrecy - leads to distrust delusions and schizophrenia
Double bind - bateson et al described child trapped in situations with fear of doing wrong but receive conflicting messages about what is wrong and cant express feelings of unfairness - when they get it wrong child is punished by withdrawal of love leading to delusions
Expressed emotion - criticism, hostility and over involvement towards patient leads to stress and relapse
Cognitive -
dysfunctional thought processing - lower levels of info processing in some parts of brain suggest cognition impaired
metarepresentation - our ability to reflect on thoughts - dysfunction disrupts ability to recognise our thoughts as our own leading to delusions and hallucinations
dysfunction of central control which leads to speech poverty
Psychological explanations for schizophrenia AO3
-biological factors overlooked - psychological explanations hard to reconcile with biological - maybe both separately produce same symptoms raising questions of whether both are really scz - diathesis stress model - diathesis biological or psychological
-cognitive explanation is direction of causality - unclear whether cognitive factors cause of neural correlates and abnormal nuerotransmitter levels ie does dysfunctional metarepresentation lower dopamine in superior temporal gyrus or is it opposite - questions validity of explaining origins of scz
-family based explanations weak evidence - poor childhood experiences can cause scz but little evidence to support schizophrenogenic mother, expressed emotion or double bind - led to blaming parents already suffering over childs symptoms and based on clinical observations which are open to interpretation - undermine appropriateness and creditibility of family based explanation
Biological therapies for schizophrenia: Drug Therapy AO1
Typical antipsychotics -
dopamine antagonists - ie chlorpromazine which acts on histamine receptors and has a sedative effect to calm anxious, reduce action of dopamine by blocking dopamine receptors in synapses reducing its action - intitially dopamine builds up but then lowers normalising neurotransmission in key areas reducing symptoms.
Atypical antipsychotics -
ie clozapine targets dopamine and serotonin, binds to dopamine receptors like chlorpromazine but also does on serotonin and glutamate too - more effective than typical reducing depression and improving cognition and mood which causes 50% of scz suicide
Risperidone is as effective as clozapine but binds more strongly and so effective in smaller doses than most antipsychotics but less side effects so safer
Biological therapies for schizophrenia: Drug Therapy AO3
-side effects - typical associated with dizziness drowsiness and long term leads to grimacing as dopamine is very sensitive - most serious neuroleptic malignant syndrome caused by blocking dopamine action in hypothalamus which disrupts regulation of many systems, atypical have less but still exist - serious limitation
-theoretical objection - tied up w dopamine hypothesis and too much dopamine in subcortex of brain but evidence proves this incorrect that dopamine levels mayb too low so antipsychotics dont work - undermined faith of ppl
-doubts of true effectiveness - healy suggests data from drug trials published multiple times overexaggerating positives and most review short term - have calming effect so postive effect but might not be acc reducing psychosis - effectiveness overestimated by empirical research
-chemical cosh - used in hospitals to calm patients and make them easier to work with than for patients - short term use to calm patients recommended by nice but seen as human rights abuse and raises ethical issues
Psychological therapies for Schizophrenia AO1
CBT - identify and change irrational thoughts, helps to understand symptoms and its effect on behaviour - offering explanation for theses symptoms reduces anxiety and helps realise belief isnt real
Family therapy - reduce expressed emotion within family by improving communicating and interaction and stress within family to reduce relapse, pharoah et al (2010) strategies for family therapists to reduce relapse ie reduce stress, guilt and improve understanding
Token economies - tokens based on operant conditioning to manage behaviour in hospitals, tokens given to those carrying out desirable behaviour which reinforces desirable behaviour which can be swapped for a reward - secondary reinforcers as they only have value due to learnt association with innate primary reinforcers
Psychological therapies for Schizophrenia AO3
-Help but dont cure - cbt helps patients make sense of symptoms, family therapy reduces stress of living with scz and token economies help to make patients behaviour more socially acceptable - shouldnt be confused with curing same with biological therapies - just reduce severity of symptoms so more desirable
-ethics - token economies controversial as ill cant get privileges as less able to comply with desirable behaviours than moderately ill so discrimination and cbt challenges paranoia - freedom of thought ie political beliefs - ethics make it controversial
-quality of evidence - small scale studies compare before and after and have positive results but lack control group or random allocation - effectiveness overestimates by evidence
-alternative therapies under researched - ie nice recommends art therapist who can work with patients but these arent well researched so unclear effectivenss - questions whether underresearched therapies made available
Interactionist approach to schizophrenia AO1
Diathesis stress model - vulnerabilty and stress trigger trigger schizophrenia
meehls model - person who has schizogene vulnerable to stress ie from schizophrenogenic mother so isnt sufficient for scz on its own, need stress too
many genes increase vulnerability, diathesis doesnt have to be genetic could be early psychological trauma affecting brain development
Antipsychotic medication and cbt - turkington et al suggests adopting interactionist approach cant adopt purely biological approach, uk more interactionist treatment than us
Interactionist approach to schizophrenia AO3
+research support - tiernari et al studied children adopted from schizophrenic mothers, adoptive parents parenting styles compared with control group of those with no genetic risk - child rearing with criticism and no empathy implicated in development of scz but only for those with genetic risk - strong support for interactionist approach, genetic vulnerability+family stress=schizophrenia
-original diathesis stress model too simple - multiple genes increase vulnerability no schizogene, stress comes in many forms - researches believe stress has biological factors ie houston et al showed sexual trauma was diathesis and cannabis a trigger - old model of diathesis being biological and stress being psychological too simple
-dont know how diathesis stress works - strong evidence to suggest vulnerability w stress leads to scz but dont understand mechanisms by which symptoms appear and how both vulnerability and stress PRODUCES IT - doesnt undermine support but we have incomplete understanding
-treatment causation - turkington et al argued biological and psychological therapy combined doesnt mean interactionist is correct - fact that drugs help doesnt mean scz is biological in origin - treatment causation fallacy - superior outcomes of combined therapies shouldnt be overinterpreted in evidence to support interactionist approach
