Schizophrenia Flashcards
(17 cards)
DSM-5 classification
at least 1 postive symptom
ICD-11 classification
two or more negative symptoms
positive symptoms
hallucinations: unusually sensory experiences
delusions: irrational beliefs
negative symptoms
avolition:feeling demotivated known as ‘apathy’
speech poverty:reduction in quality and amount of speech
evaluation of diagnosis
- reliability:Cheniaux et al:2 psychiatrists independently diagnosed 100 patients and results were different.Means that it isn’t accurate enough
- Co-morbidity:Buckley et al-50% of patients also have depression
- symptom overlap:bipolar and Schizophrenia share similar symptoms
- gender bias:women aren’t as diagnosed as much as men due to different criteria
- culture bias:African americans are more likely to be diagnosed than whites people
Biological explanation (1)-genetic
Genetic vulnerability:genetic component to SZ which predisposes people to illness
It’s polygenic:not just 1 gene but a few-Ripke et al-found 108 genes-means little predictive power
It’s aetiologically heterogeneous:certain genes may cause it people but other genes in other people
Family studies-genetic-include evaluation
Gottesman:found the more similar the genetic DNA, the
probability of sharing SZ.48% for MZ and 17% for DZ
evaluation:environmental factors needed to be factors as not 100%
Twin studies-genetic-includes evaluation
Joseph:concordance rate of 40.4% for MZ and 7.4% for DZ
evaluation:environmental factors could also play a part as concordance rate isn’t 100%
Adoption studies-genetic
Tienari et al:studied 19,000 children adopted away from SZ mothers.Compared parenting styles of adoptive mothers with control group with children with no genetic risk.
6.7% of children who’s mother had SZ developed SZ compared to 2% who weren’t.
Biological explanation (2)-dopamine hypothesis
neurotransmitters:brain chemical messengers work differently with patients with mental illness
Dopamine:involved in SZ
-hyperdopaminergia:too much dopamine in the subcortex-linked to hallucinations
hypodopaminergia:low levels of dopamine in frontal cortex
evaluation:
-mixed evidence for the role of dopamine-Ripke et al found 108 candidate genes for SZ,but not all linked to dopamine gluteamate as well
-recductionist,very simplistic explanation
-support- Antipsychotic drugs bring down dopamine levels and it reduces symptoms
Biological explanation(3)- neural correlates
measurements of the structure/function of the brain that correlate with an experience
negative symptoms:activity in the ventral striatum is linked to avoiltion which results in lack of motivation
positive symptoms:reduced activity in the superior tempoeral gyrus is linked to hallucinations
evaluation:
correlation not causation-SZ could cause this problem or a 3rd factor affects both
Biological treatments for SZ
Antipsychotic drugs(tablets syrup or injection)
-Typical antipsychotics eg:chlorpromazine,400-800mg,effective sedative
-Atypical antipsychotics:Clozapine 300-450mg-bind to dopamine receptors+also effects serotonin transmission.Improves mood but risk of blood disease
-Atypical (recent):risperdone,has less side effects but just as effective,4-8mg,binds to dopamine receptors+effects transmission of dopamine
evaluation:
+research support-Thornely et al found that chlorpromazine was more effective than placebos
-bias-funded by drug companies therefore may lack validity in findings
-side effects-effects quality of life
+time and cost
Psychological treatments for SZ
CBT:
-talking therapy which identifies irrational thoughts
-helps patient understands their symptoms
Family therapy:
-aims to reduce expressed emotion and improve communication.Within families not individuals
-improves family functioning by helping them to solve problems,reduces anger+guilt
Token economies:
-based on operant conditioning techniques and used to manage behaviour
-tokens given to reinforce ‘target’ behaviour
-tokens have no value but can be swapped later for rewards eg sweets
evaluation:
+March et al found CBT and drug therapies are 81% effetive on their own but together 86% effective
-ethical issues of token economies-discriminate against ill patients who aren’t able to do this
-helps but doesn’t cure-biological therpies help symptons where’s CBT helps people make sense of their symptoms
interactionsist approach
diathesis stress model
Diathesis (vulnerability) + stress (trigger) =SZ
Meehls model:
-SZ is the result of a combination of a schizogene and stress in their childhood EG-schizophregenic mother
-gene leads to development of schizotypic personality, one characteristic of which is vulnerable to stress.Stressful events in life may trigger SZ in genetically vulnerable people
MODERN APPROACH:
-diathesis is not due to a single schizogene but due to a range of genes each increasing vulnerability a little bit (polygenic)
-early psychological trauma affects brain development EG-child abuse can affect the HPA system so becomes over reactive->vulnerable to stress
-drugs make you more vulnerable stress (cannabis).7 times more likely
TREATMENT:
-combination of treatment is used.Biological (drugs) and psychological (CBT).Turkingtom et al says it’s possible to believe SZ is biological and still use psychological treatments to reduce symptoms.As long as you accept interactionist approach
-In britain it is standard to use a combination of therapies
Psychological explanations for SZ-family dysfunction
family dysfunction:
-SZ is due to family experiences of conflict,communication,criticisms and control
1.Schizophrenigenic mother:
-mothers who are cold,rejecting and controlling.Father is passive creates a family characterised by tension
-leads to distrust and stress which leads to paranoid delusions and SZ
2.Double blind
-child receives mixed messages about how to behave in different situations or parent emotions
-feel unable to comment on the unfairness of it
-learn the world is confusing and dangerous
-leads to delusions,speech poverty and avoilition
3.High EE (expressed emotion)
- high levels of emotion expressed to the patient usually family communication style involves:
critical
hostility
emotion over involvement
evaluation:
+Tienarie et al-adopted children from SZ mothers.Adoptive parenting style assessed and compared with control group.Conflict and criticism implicated SZ
-weak evidence-based on oberservation
-social sensitive-blame parents for SZ
Psychological explanation for SZ-cognitive
cognitive
-focus on the role of mental processes
1.mental representation
-ability to reflect thoughts and behaviour allowing insight into our own intentions and goals
-SZ patients have a dysfunction in mental representation because they fail to recognise there own thoughts and actions as being carried out by themselves
2.central control
-cognitive ability to suppress automatic response while we perform deliberate actions instead
-why SZ patients have disorganised speech, each word they say triggers an association
-normally people can suppress these thoughts and continue with conversation
evaluation
+-reductionist doesn’t account for other factors eg biological
+can be used for therapy
+stirling et al:30 SZ patients vs 18 controls on cognitive tasks(stroop test)SZ patients were 2x slower to suppress impulse to read the world->central control dysfunction
Evaluation of diatheis stress model
+support for dual role
Tienari et al studied adopted children away from SZ mothers.Adoptive parents parenting styles were assessed and compared with a control of adopted children with no genetic risk.High EE was implicated in the development of SZ for those with genetic risk
+real world application
Tarrier et al:found that a combination of treatments worked the best for patients rather than solo treatments
-treatment causation fallacy
Turkington et al:superior treatments does not mean interactionist model for SZ
