schizophrenia Flashcards
(16 cards)
CLASSIFICATION OF SCHIZOPHRENIA
POSITIVE/NEGATIVE SYMPTOMS:
positive: hallucinations & delusions
negative: speech poverty & avolition
MANUALS:
DSM-5: USA, 2/5 symptoms, at least 1 positive
ICD-10: international, any 2 symptoms
RELIABILITY:
Osorio assessed 180 individuals, against DSM-5
1) test-retest: +0.92
2) inter-rater: +0.97
VALIDITY:
Cheniaux assessed 100 individuals against DSM vs ICD
39 DCM, 68 ICD
Rosenhan - 12 healthy confederates faked hearing the word ‘thud’. All were admitted, spent average 19 days
ISSUES:
1) co-morbidity
Buckley 50% depression, 47% substance abuse, 23% OCD
2) symptom overlap
e.g. bipolar includes positive symptoms
3) gender bias
men diagnosed 40% more frequently
4) cultural bias
Pinto & Jones Afro-carribean 10x more likely to be diagnosed. symptoms have different meanings
BIOLOGICAL EXPLANATIONS (GENETIC & NEURAL)
Ao1
GENETIC:
family studies:
Gottesman found the more related, higher concordance
MZ twins 48%, siblings 9%, parents 6%
candidate genes:
polygenic, Ripke studied 37,000 Sz with 113,000 controls. found 108 separate genes related
paternal age:
Brown 0.7% (under 25) to over 2% (over 50)
NEURAL CORRELATES:
original hypothesis:
Seeman theorised unusually high levels of dopamine (excitatory) cause Sz. Might have abnormally high levels of D2 receptors, causing excess dopamine - e.g. in Broca’s area can cause positive symptoms
updated hypothesis:
Davis - high levels not found in all Sz, and clozapine works.
Suggests too low dopamine in PFC can explain negative symptoms
both hypo and hyperdopaminergia can cause Sz, and may even be linked
BIOLOGICAL EXPLANATIONS
Ao3
GENETIC
strengths:
- Tienari found adopted kids with Sz mother more likely to develop
-Hilker found concordance rates 33% MZ twins
limitation:
- environmental factors - birth complications, cannabis
NEURAL:
strengths:
-Curran amphetamines increase dopamine & worsen/induce Sz
-antipsychotics work on Sz.
limitation:
-role of glutamate, brain scans show consistently raised levels in Sz patients
PSYCHOLOGICAL EXPLANATIONS - FAMILY DYSFUNCTION
Ao1
1) Schizophrenogenic mother
Fromm-Reichmann suggested a cold, controlling, rejecting mother & passive father. family dynamic of tension and secrecy
2) Double-bind theory
Bateson suggested mixed messages - unable to comment on the unfairness of this. When do the ‘wrong thing’ they are punished, think world is dangerous and confusing
3) Expressed emotion
focus on relapse rather than development.
Hostility, Emotional over involvement, verbal criticism
PSYCHOLOGICAL EXPLANATIONS - FAMILY DYSFUNCTION
Ao3
STRENGTHS:
- Read found adults with Sz more likely to have type c attachment. 69% women 59% men with Sz have experienced childhood abuse
LIMITATIONS:
- poor evidence for traditional family explanations, based on informal assessments of personality
- socially sensitive, blame the mother
PSYCHOLOGICAL - COGNITIVE EXPLANATIONS
Ao1
role of mental processes - dysfunctional thought processing.
Frith identified two types:
1) meta-representation dysfunction
ability to reflect on own thoughts/behaviour and actions of others - cannot recognise thoughts caused by ourselves not anyone else. causes hallucinations/delusions
2) lack of central control
cannot suppress automatic responses while performing deliberate ones - causes disorganised speech/thoughts/behaviour
COGNITIVE EXPLANATIONS
Ao3
STRENGTH
- Stirling compared 30 Sz/controls on Stroop test. Sz took twice as long, suggesting impaired cognitive processes
LIMITATION
- only proximal explanation not distal. only focuses on current cognition/reasons for symptoms not initial cause.
BIOLOGICAL TREATMENT
Ao1
Drug therapies through antipsychotic medication. Work by reducing dopaminergic transmission.
Typical antipsychotics
link to dopamine hypothesis, block dopamine receptors. Initially leads to increase in production but is later reduced.
e.g. chlorpromazine, usually 400-800mg per day. also has sedative effect, useful
side effects: sedation, dizziness, weight gain, NMS
Atypical antipsychotics
work similarly to typical but aim to reduce side effects.
e.g. clozapine, max 450mg per day, binds to dopamine receptors. also works on serotonin and glutamate, increasing their levels. beneficial to depression comorbid patients
side effects: aranulocytosis
e.g. risperidone, 12mg max per day. binds to dopamine and serotonin. more effective, smaller doses
side effects: fewer but agitation, anxiety etc.
BIOLOGICAL TREATMENTS
Ao3
STRENGTHS
- Meltzer found clozapine effective in 30-50% of treatment resistant patients
- Gilbert meta analysis 53% relapsed within 10 months stopping meds, 16% continued meds
LIMITATIONS
- counterpoint- doesn’t treat root cause only symptoms, relapse when stop taking
- side effects, ethical issues of funding from drug companies.
PSYCHOLOGICAL TREATMENTS
Ao1
1)CBTp
(CBT psychosis) aims to identify and stop dysfunctional thought processing.
Recommends at least 16 sessions.
4 stages:
Recognising the dysfunctional thoughts
Educating/explaining - where they come from, not real
Normalising - extension of ordinary experience, no need to stress
Testing - reality test the beliefs
2) Family therapy
aims to improve quality of interactions and communication
Pharoah identified strategies:
1) reduces negative emotions (levels of EE, especially anger/guilt/stress)
2) improves family’s ability to help
agree on aims of therapy, educate towards Sz, balance help with own lives
Burbach identified 7 stages:
1) basic info sharing & support
2) identifying resources
3) mutual understanding/safety
4) identify unhelpful behaviour
5) skills training (e.g. stress man.)
6) relapse prevention training
7) maintenence for future
PSYCHOLOGICAL TREATMENTS
Ao3
CBT:
strength- Juahar meta analysis of 34 studies, found small but significant effect on positive & negative symptoms
limitation- may be palliative not curative - biological in nature
FAMILY THERAPY:
-strength: McFarlane found family therapy reduced relapse by 50-60%
-strength: benefits the whole family, strengthens ability to give support
MANAGING Sz - TOKEN ECONOMIES
Ao1
Typically used for long term hospital patients, especially maladaptive negative symptoms e.g. bad hygiene, avolition
Rationale- Matson behaviours TE can tackle:
personal care, condition-related behaviours, social behaviours
benefits:
1) improves quality of life
2) normalises behaviour, e.g. getting dressed. good for institutionalised patients
MANAGING - TOKEN ECONOMY SYSTEMS
Ao3
STRENGTH
Glowacki meta analysis showed reduction of negative symptoms/unwanted behaviours
LIMITATION
-ethical issues, imposing other peoples norms.
-hard to impose outside hospital
INTERACTIONIST APPROACH
Ao1
EXPLAINATION:
Diathesis-stress model means genetic vulnerability and stressor are required.
Meehl theorised Sz caused by a single gene, someone without could never develop. Carriers could develop when exposed to trauma.
However Ripke discredits
Modern understanding:
- multiple genes not one
physiological factors not just family
- HPA system
early trauma affects the developmental brain. HPA system becomes overactive
-Cannabis smoking (increases dopamine)
TREATMENT:
Combines drug therapy and CBT.
-Drugs given first to alleviate symptoms, calm patients.
-makes more responsive to therapy
INTERACTIONIST APPROACH
Ao3
EXPLANATION
strength- Tienari compared adoptees with Sz parents/not. Found high criticism/conflict in child rearing affected those genetically vulnerable
limitation- Meehl’s schizogene oversimplified.
TREATMENT:
strength- Tarrier allocated patients to groups of drug therapy& CBT/counselling or control. combo groups showed lower symptom levels
limitation - more commonly diagnosed in urban areas, stressors. might actually be due to better medical access
