Schizophrenia 3 Flashcards
Definition
A psychotic disorder characterised by a loss of contact with reality
diagnosed by a psychiatrist from DSM
two or more positive symptoms in at least a month
Positive symtoms
Hallucinations:
unreal perceptions of environment
(auditory, visual, taste, olfactory)
Delusions:
bizarre beliefs about reality that seem real to the person with SZ but they’re not real
paranoid, involves ‘selves; inflated beliefs about their importance
Disorganised speech:
result of abnormal thought processes where the individual has difficulty organising their thoughts which shows up their speech
catatonic behaviour:
bizarre and abnormal motor movements
e.g. holding a rigid stance, moving in a frenzied way
Negative symptoms
Speech poverty:
lessening of speech fluency and productivity
thought to reflect slowing/blocked thoughts
Avolition:
reduction of, or inability and persistence in goal-directed behaviour e.g. sitting for hours everyday doing nothing
Affective flattening:
a reduction in range and intensity of emotional expression including facial expressive, eye contact and body language
Anhedonia:
loss of interest/pleasure in almost all activities or lack of reactivity to normally pleasurable stimuli
Reliability in diagnosis and classification of SZ
Test-retest
agree on diagnosis
Beck et al. - inter-rater reliablilty of psychiatrists
found 54% reliability
Issue of cultural differences in diagnosing SZ
Copeland - US and UK agree on diagnosis 1.2% of the time in diagnosing SZ
- only one positive symptom needed if ‘bizarre’ delusions; unreliable symptoms; difficult to differentiate between ‘bizarre’ and ‘non-bizarre’ delusions; senior psychiatrists asked difference and found inter-rater reliability to be as low as 0.40 correlation
Validity in diagnosis and classification of SZ
are you measuring what you’re meant to be measuring?
e.g. diagnosing SZ when its something else
issue of gender bias in diagnosing SZ
DSM and ISM geared towards diagnosing white MEN
Symptom overlap:
Ellison and Ross - people with dissociative identity disorder (DID) have more positive symptoms than SZ; different mental health disorders share symptoms; validity issue of correct diagnosis
Co-morbidity:
chance of having 2 mental health disorders at the same time e.g. depression and SZ = 50%
- consequences of co-morbidity; Weber et al. - psychiatric and behaviour-related diagnosis of hospital discharge records had 45% co-morbidity
results in lower medical care; harder to deal with
This adversely affects prognosis for SZ patients
- Differences in prognosis;
Bentall et al. - comprehensive review of symptoms, prognosis and treatments; SZ not useful scientific category, little predictive validity as big variety in prognosis, more to do with gender
Biological explanations of SZ
Genetic factors:
Family studies
Adoption studies
Twin studies
Neural correlates:
Dopamine hypothesis
Revised dopamine hypothesis - Davis and Kahn
Brain areas:
decreased grey and white matter
Genetic factors of SZ
Family studies: Gottesman - both parents with SZ 46% chance, 1% if person chosen at random
Risk increases with degree of increasing genetic relatedness
BUT siblings 9% despite same % DNA as DZ; environment
Twin studies - Gottesman - MZ twins 48% and DZ 17%
BUT not 100%; environment
and always small sample size
Adoption studies - Tienari et al. - biological mothers with SZ had concordance rates of 6.7% than parents without SZ of 2%
BUT 2% still higher than person at random 1%; environmental influences
Neural correlates explanation for SZ: Dopamine hypothesis
Abnormally high D2 receptors on receiving neurone
so more dopamine binds and more neurones fire
so high dopamine levels; linked to SZ
+ Amphetamine overdoses increase dopamine, flooding synapses and causing a drug induced psychosis, producing SZ-like symptoms
e.g. cocaine, cannabis, ecstacy
+ Parkinson’s - low dopamine levels
treatments can increase dopamine levels, if too much, SZ-like symptoms can occur
+ Leucht et al. - meta-analysis of anti-psychotics compared to placebo; significantly more effective than placebo in treating positive and negative symptoms
+ Lindstoem et al. - PET scans of SZ patients, use L-DOPA which makes dopamine more than control; has a role in SZ
Neural correlates explanation for SZ: revised dopamine hypothesis
Davis and Kahn
high levels of dopamine in the mesolymbic pathways causing positive symptoms
low levels in the mesocortex pathways causing negative symptoms of SZ
+ Wang and Deutch induced dopamine depletion in the prefrontal cortex of rats causing cognitive impairment; able to reverse using atypical antipsychotics
+ Treatment of SZ symptoms using dopamine antagonists; 60% effective. Also, more impact on positive symptoms than negative so potentially different causes for positive and negative
BUT not 100%; has an influence
Neural correlates explanation for SZ; Brain areas
Grey matter: cell bodies
SZ patients have a lower volume of grey matter in brain than control
White matter: myelin sheath
SZ patients reduced myelination of white matter pathways than control
+ Application - if scan, potential to detect SZ early so early, targeted treatment
Psychological explanations for SZ: family dysfunction
Double bind theory - Bateson et al.
abnormal communications; contradictory messages; lack of congruence
development of an internally coherent reality construction is prevented; in the long-term, manifests itself as SZ symptoms
Expressed emotion
Negative climate; family talk about the patient in a critical/hostile manner; talk more listen less
+ Linszen et al. - patients returning to high levels of EE are 4x more likely to relapse than control
leads to arousal and stress; low tolerance of environmental stimuli and emotional comments/family interactions
+ Berger - higher recall of double bind statements from mothers for SZ patients than non-SZ
BUT relies on the recall of SZ suffers; recall likely impaired so may not have an effect
+ Noll - undemanding families can help lower the use of anti-psychotic drugs
Psychological explanations for SZ: cognitive explanations
cognitive explanations of delusions:
- bias interpretations of own experiences; egocentric
- jump to conclusions and link external events inappropriately
- reality check unsuccessful; won’t admit they are wrong
- don’t recognise cognitive distortions ‘impaired insight’ so can’t substitute more realistic explanations
cognitive explanations of hallucinations:
- excessive attention to auditory stimuli
- hard to separate ideas about themselves from sensory input
- translate to ‘you are evil’ and heard as a voice
- ACTUAL input overridden
- absent reality check
+ Sarin + Wallin - delusional patients showed faulty information processing; supports idea of jumping to conclusions; faulty cognitions and impaired self monitoring
+ NICE review - CBTp more effective than anti-psychotic medication in reducing symptom severity
- Hawes + Murray - ignores other aspects e.g. neurochemicals; integrated approach may be more beneficial
Drug therapy
Typical anti-psychotics: decrease dopamine activity
only reduce positive symptoms
- Kapur et al. - 60-75% of D2 receptors blocked in mesolyombic pathways but similar number blocked in other pathways so undesirable side effects
- Ethics - likely negative cost-benefit analysis if side-effects; deaths and psychological consequences taken into account
Atypical anti-psychotics: block fewer D2 receptors
block temporarily and rapidly dissociate
reduce both positive and negative symptoms
+ Fewer side effects than typical anti-psychotics
BUT potentially lethal blood disorder
+ Leutch et al. - meta-analysis; after 1 year, relapse 37% higher for placebo than anti-psychotics
- Ross and Read - when people prescribed anti-psychotics it reinforces the idea that there is something wrong with them; prevents them from looking for solutions that may alleviate stressors e.g. current circumstances
CBT for treating SZ
Changing faulty belief systems
= Assessment; goals, motivation and dealing with distress
= Engagement; empathy and collaboration
= ABC model; irrational to rational
= Normalisation; psychosis in context
= Critical collaboration; illogical understood and reframed
= Alternative explanations; maladaptive beliefs explored
+ CBTp reduces rehospitalisation rates up to 18 months after compared to standard care alone (drugs)
+ CBTp more effective in reducing symptom severity than standard care alone
- Meta-analysis; no significant difference between CBT and standard care for outcomes related to suicide to treatment adherence
- Not suitable for all patients e.g. if too paranoid to form trusting alliances with practitioners
- Not available for all and more expensive than drug therapy
Family therapy for treating SZ
Family learn more constructive ways of communicating
Aims to reduce high levels of EE within the household; reducing chances of relapse if less hostel and overly involved families
- Pharoah et al. - meta-analysis of the effectiveness of family therapy compared to standard care alone (drugs)
= more patients complied with medication if family interventions used, patients less likely to relapse and increased social functioning
BUT main reason for effectiveness may be because of increased medication compliance rather than intervention
+ Garety - relapse rates reduced by 25% following family therapy compared to standard care alone
+ NICE review - economic benefits when used alongside standard care as lower relapse rates due to reduced rehospitalisation costs
