explainations

• What re the possible explanations of schizophrenia

  - Biological

  --> genetic

  --> neural

  - Psychological

  --> cognitive

  --> family dysfunction
• What are the genetic explanations for schizophrenia?

  - The role of candidate genes

  - Family studies

  - Twin studies

  - Adoption studies
• What are the main ideas of the genetic explanation for schizophrenia

  - Not just from 1 gene, but lots of genes potentially impacting it

  - different combinations of genes can make schizophrenia more likely

  - Passed down through family
• How are family studies used as a genetic explanation of schizophrenia

  - scz is more common in relatives of people with schizophrenia

  - closer degree/ greater genetic relatedness increases risk
• Research support for family studies and schizophrenia

  - Gottesman

  --> children with 2 schizophrenic parents had a 46% chance/ concordance rate for developing schizophrenia

  
  

  --> 1 schizophrenic parent has a 13% increased chance/ concordance rate

  
  

  --> concordance rate for those with a sibling with schizophrenia had a 9% chance/ concordance rates of developing schizophrenia
• How are twin studies used as a genetic explanation of schizophrenia

  - suggests similarity in diagnosis is due to genetics

  
  

  - In twin studies by joseph et al (2004) found:

  --> meta analysis

  --> MZ twins had a concordance rate of 40.4%

  --> DZ twins had a concordance rate of 7.4%

  
  

  (showing genetic link due to MZ having higher concordance, however not 100% showing other factors may be at play)
• How are adoption studies used as a genetic explanation of schizophrenia

  - Genetically similar or identical, but grow apart (role of environment)

  
  

  - Tierari (2000)

  --> 164 adopties with a biological mother with schizophrenia

  --> 197 control adoptees with non schizophrenic mothers)

  --> 11 (6.7%) of these adoptees were also diagnosed with schizophrenia

  --> only 4 (2%) adoptees in the control groups with no schizophrenic biological mother were diagnosed

  --> shows that a liability to schizophrenia due to genetics can be "decisively confirmed"
• What evidence is there fore schizophrenia being polygenic and the role of candidate genes?

  - Ripke et al (2014)

  --> identifies 108 genes that can help to increase risks of schizophrenia

  
  

  - Sekar et al (2016) (follow up of Ripke group)

  --> CC4 gene was associated with a higher risk of schizophrenia

  --> CC4 gene linked to synaptic pruning, so the greater the CC4 expression the greater pruning of connections, increasing the schizophrenia risk

  
  

  - Singh et al (2016)

  --> identifies SETD1A gene

  --> neural communication, regulation of other genes

  --> as "strong linked" with schizophrenia
• What are candidate genes?

  A number of genes that may give a small increased risk or vulnerability to schizophrenia
• Support for the genetic explainations

  Real world application

  + candidate genes can be useful for health care professionals

  
  

  Research support

  - family studies

  - twin studies

  - adoption studies

  - Genetic studies
• Limitations of genetic explanations

  - Lacks predictive validity as genes do not always result in schizophrenia

  
  

  Anxiety

  - Can make patients more anxious if they know that they have certain genes that could predispose them, however they will not know how high the risk is and there will be uncertainty, which could result in increased anxiety

  
  

  Determinist

  
  

  Socially sensitive

  
  

  Can lead to genetic screening which can have ethical implications with embryo screening

  
  

  Hard to untangle nature and nurture
• What are the neural explanations of schizophrenia?

  - Neural correlates

  - The dopamine hypothesis
• What are neural correlates?

  - A measure of the structure or function of the brain

  - This correlates with an experiences

  - and can cause both positive and negative symptoms
• What neural correlates cause negative (-) symptoms of schizophrenia

  - The Ventral Striatum (mid brain) is associates with anticipation and reward

  - this therefore causes negative symptoms of schizophrenia such as avolition as this is a loss of motivation due to the neural changes
• What neural correlates cause positive (+) symptoms of schizophrenia

  - The Superior Temporal Gyrus

  - The Anterior Cingulate Gyrus

  - Both associated with hallucinations, mostly auditory

  - Shows how they can help to contribute to positive symptoms of schizophrenia
• What are the two pathways of the dopamine hypothesis?

  - The Mesolimbic pathway (+)

  - The Mesocortical pathway (-)
• Explain the mesolimbic pathway in the dopamine hypothesis and explaining SCZ

  - excess dopamine

  - Positive symptoms

  - in the mid brain through to the limbic system (NAcc)

  - involves the reward circuit (addiction and motivation)

  - 'the subcortex
• What symptoms are associated with the mesolimbic pathway?

  + positive
• Explain the mesocortical pathway in the dopamine hypothesis and explaining SCZ

  - Low dopamine

  - negative symptoms

  - in the midbrain and pre frontal cortex (frontal lobes)

  - involves executive function (attention, control, language)
• What symptoms are associated with the mesocortical pathway?

  - negative
• Support for neural explanations of schizophrenia

  The effectiveness of drug treatments

  + Leucht et al (2013), meta-analysis

  --> Drugs shown to be better than placebos

  --> 2 groups

  ----> group 1 = antipsychotic (27% relapse rates) (73% effective)

  ----> group 2 = placebo (64% relapse rates) (36% effective)

  
  

  + shows evidence for a biological cause due to biological treatments bing effective

  - However placebos were seen to be 36% effective, and so this decreased the validity and credibility of the study

  - Also could be prone to publication bias

  
  

  Research support

  + Drugs increasing dopamine increase symptoms

  + and this induces hallucinations and other negative symptoms

  
  

  + Wang & Deutch (2008)

  --> animal research

  --> increased dopamine depletion in the pre-frontal cortex of rats

  --> resulted in cognitive impairment and negative symptoms

  --> this was fixed with drugs

  
  

  - But this is animal research and so should/ can animal findings be generalised to humans
• Limitations of neural explanations of schizophrenia

  Post-mortem evidence

  - no abnormalities in dopamine in the brains of those with schizophrenia

  
  

  Noll (2009)

  - medication does not improve symptoms such as hallucinations and delusions in 1/3 of people

  - some people have delusions and hallucinations are present without abnormal dopamine levels

  - Challenges validity

  - suggests another factor may be at play and causing symptoms of schizophrenia
• What are the types of psychological explanations are there for schizophrenia?

  - Cognitive

  - Family dysfunction
• What was the historical explanation of schizophrenia?

  The schizophrenogenic mother
• What was the schizophrenogenic mother?

  - Psychological explanation of schizophrenia

  - Psychodynamic, based on upbringing

  - When a mother is cold, rejecting and controlling, and contradictory

  - The family climate is tense, untrusting, and relies on secrecy

  - This distrust leads to paranoia leading to schizophrenia

  
  

  Problems:

  - places blame on the mother
• What principles and theories are involved in family dysfunction?

  - Double bind theory

  - Expressed emotion

  (schizophrenic mothers)
• What are the key ideas of the double bind theory

  - When parents used mixed/ contradictory messages

  - Believes schizophrenia is a result of the environment
• What is the double bind theory?

  - mixed messages

  - impacts developing a coherent sense of reality

  - confusing environment

  - cant win, emotionally punished if right or wrong

  - children learn to question everything

  - explains symptoms such as disorganised speech and thinking
• What is the key idea of expressed emotion?


  - where family and parents emphasise their sacrifice and guilt

  - typically acts as a trigger
• Overview of expressed emotion

  - Verbal criticisms

  - can get abusive and violent

  - hostile environment

  - guilt and sacrifice

  - over-involvement

  - stress

  - explains relapse

  - explains a trigger for biological predisposition
• support for the family dysfunctions theory


  Effective therapies

  +family therapy has been shown to be effective at reducing symptoms of schizophrenia

  
  

  Research support

  + Berger (1965)

  --> people with scz reported higher recall of double bind statements from their mothers compared to people without scz

  - however this is self-report data it is unreliable, those with scz may interpret things differently or incorrectly

  
  

  The importance of the nature of a family relationship

  + Tienari (1994)

  --> adoption study

  --> children with bio parent with scz more likely to develop this than children without parents with scz

  --> difference emerged only in situations where adopted family were disturbed according to psychologists

  --> suggests scz occurs under certain environmental conditions and that genetics are not completely responsible
• Limitations of the family dysfunction theory

  individual differences with expressed emotion

  - Altorfer et al (1998)

  --> found 1/4 of patients studies showed no physiological responses to stressful comments from their relatives

  
  

  Vulnerability to EE may be physiologically based

  - Lebell et al (1993)

  --> claimed how patients. behaviour of their relatives is important

  --> In cases where high EE behaviours are not perceived as being negative and stressful

  - patients can do well regardless of the family environment
• What are the 5 cognitive aspects of the psychological explanations of schizophrenia?

  - Metarepresentation

  - Central control

  - Egocentric bias

  - reality testing

  - sensory hypervigilance
• Which cognitive aspects do people with schizophrenia lack?

  - Metarepresentation

  - Central control

  - reality testing
• What is (a lack of) metarepresentation?


  - The ability to reflect and recognise our own thoughts and behaviour

  - people with schizophrenia have a lack of metarepresentation

  - This helps to explain hallucinations and delusions

  - Helps us to interpret behaviour of ourselves and others

  
• What is (a lack of) central control?

  - The ability to suppress automatic thoughts

  - people with schizophrenia have a lack of central control

  - This helps to explain disorganised speech, this is because those with schizophrenia cannot suppress thoughts and associations for certain words and phrases in conversation, as certain things can act as triggers

  - Supported by the Stroop test

  
• What is (a lack of) reality testing?


  - Where people cannot interpret what is real and what is not

  - Inability to recognise distorted or irrational behaviour

  - This can explain delusions and paranoia

  - Cannot perceive what is realistic and what is not
• Which cognitive aspects do people with schizophrenia have to experience?

  - Egocentric bias

  - sensory hypervigilance
• What is an egocentric bias?

  - Where people perceive themselves as the central component in events causing people with schizophrenia to jump to incorrect conclusions of external events

  - people relate irrelevant events to make false conclusions

  - Linked to and can help to explain delusions
• What is sensory hypervigilance?

  - where people with schizophrenia pay attention and are very aware and focuses on excessive sensory information

  - mainly auditory (e.g police noises may make them think they are coming to them)

  - This helps to explain hallucinations