Schizophrenia evaluation

• schizophrenia

  a psychotic disorder
• positive symptoms of schizophrenia

  hallucinations

  -auditory (hearing)

  -visual (seeing)

  -olfactory (smelling things)

  -tactile (feeling)

  
  

  delusions

  -of grandeur (thinking they are special and different from everyone else, the idea that they are napoleon or Jesus Christ)

  -persecution (thinking they are being tracked or followed by secret agencies)

  
  

  disordered thinking (thoughts are being interfered with

  -broadcast

  -insertion

  -withdrawals
• negative symptoms

  Anhedonia- when tasks that usually excite you no longer do

  
  

  Avolition- when a person cannot strive towards goal orienated behaviour

  
  

  Alogia (speech poverty) - when a person is unable to speak fluently and is very disjointed, usually having no coherent point

  
  

  Flattening of affect- when a person no longer cares or shows emotions, such as using eye contact, body language, smiling.
• how do we classify schizophrenia

  using the diagnostics and statistical manual of mental disorder(DSM)

  
  

  DSM-5 says that you must have at least one positive symptom and must last at least a month
• problems with using the DSM

  Reliability

  inter-rater reliability- when two different people get the same result using the same test, this is measured using the kappa score

  a score of 1 means there is a lot of agreement

  0 means no agreement

  
  

  Regier- schizophrenia only had a 0.46 score on the kappa score
• Rosenhan and reliability

  wanted to test the reliability of the diagnosis of schizophrenia

  
  

  He tested if "normal" mentally stable people would be diagnosed as schizophrenic

  
  

  8 people were asked to act as "schizophrenics" by saying they could hear and see things.

  
  

  8 people were called pseudo patients

  
  

  The pseudo patients tried to get admission to various hospitals in the US.

  
  

  All were admitted and 7/8 were diagnosed as schizophrenic

  
  

  When in the hospital they all behaved normally and attempted to be released

  
  

  It took them 7-50 days to be released

  
  

  The medical staff had no clue that they weren't mentally ill but the schizophrenics thought they were there to check up on the hospital.
• Rosenhan study critique


  Observational field experiment so it had high ecological validity

  
  

  But they used an old version of the DSM (DSM-II)
• Cultural differences in reliability of diagnosing

  schizophrenia

  
  

  Copeland


  Copeland gave psychiatrists in the U.K. and US a description of a patient.

  
  

  69% of US diagnosed them as a schizo

  2% of UK diagnosed them as a schizo
• Luhrmann et al and HEARING VOICES


  Compared the types of voices that were heard from Ghana India and US

  
  

  The African and Indian people heard positive voices while the Americans heard negative voices.

  
  

  So hearing voices may not be an inevitable feature of schizo
• Is the diagnosis of schizophrenia valid?

  Gender bias

  Co morbidity

  Symptom overlap
• Co morbidity

  Swets

  This is when two disorders are present at the same time

  
  

  Depression

  Anxiety

  Substance abuse

  Ptsd

  OCD

  
  

  Swets found that 12% of schizophrenics also had OCD.
• Gender differences ( gender bias)

  Goldstein


  Men are more likely to be prematurely diagnosed with schizophrenia than women

  
  

  Women are seen to be more functioning when having schizophrenia than men

  
  

  Goldstein found that men are more likely to be involuntarily hospitalised due to risks of socially deviant behaviour.

  
  

  Women are more likely to voluntarily go to the hospital.
• Gender bias

  Loring and Powell

  290 psychiatrists were asked to diagnose a man or a woman

  
  

  When male 56% diagnosed

  When female only 20% diagnosed

  
  

  Also depending on the gender of the psychiatrist, the diagnosis varied
• Symptom overlap

  Ellason and Ross

  Read

  Some of the symptoms of schizophrenia are also present in other disorders such as depression and bipolar disorder

  
  

  Ellason and Ross found that people with Dissosiative identity disorder showed more signs of schizophrenia than actual schizophrenics.

  
  

  Read argues that most schizophrenics have enough symptoms to be diagnosed with another disorder such as depression
• Evaluation of validity

  Weber (co-morbidity)

  Weber did a large study on 6 million hospital records to look at co morbidity rates.

  
  

  Psychiatric diagnoses accounted for 45% of co morbidity.

  
  

  There were also co morbid non psychiatric disorders.

  
  

  Schizo and asthma, type 2 diabetes, and hypothyroidism have been linked
• Evaluating reliability Mojtabi and Nicholson


  Psychiatrists were asked to differentiate between bizzare and non bizzare as this was on of the main symptoms for Shizo

  
  

  Inter rater reliability was only 0.40

  
  

  Therefore has a low reliability
• Biological explanations for schizophrenia

  Genetic causes

  Brain areas

  Neural correlates (neurotransmitters)
• Family studies (genetic basis)

  Gottesman


  Schizophrenia is more common when a biological relative also has schizophrenia.

  
  

  Closer the genetic relatedness the higher the likeliness.

  
  

  Gottesmans study- children with two schizophrenic parents had a concordance rate of 46%

  
  

  Children with one schizophrenic had a rate of 13%

  
  

  With a brother or sister = 9%
• Twin studies and schizophrenia

  Gottesman


  Monozygotic and dizygotic twins (100% and 50% of genes)

  
  

  40 twin studies

  
  

  Identical twins (monozygotic) = 48% concordance rate

  
  

  Non identical (dizygotic) = 17%
• Adoption studies and schizophrenia

  Tienari


  Observe the effects of genes with a different environment

  
  

  Tienari study in Finland- 164 adoptees

  
  

  Mothers with schizo =6.7% had schizo

  
  

  Compared to the control group

  
  

  In which 2% had shizo
• Evaluation of genetics

  Joseph

  Gottesman and Shields


  Never a 100% concordance rate so there must be other factors at play

  
  

  Joseph- those monozygotic twins are more likely to be treated similarly, do things together and be confused as each the other twin, so it is more an affect of environmental factors.

  
  

  Gottesman and Shields- both genes and environment are important in development of schizo
• Biological approach


  Brain Areas
• Brain areas

  Ventricular enlargement

  Damage to dorsolateral prefrontal cortex

  Occipital lobe

  "Where" system in Wernickes area
• dorsolateral prefrontal cortex

  Gur et al

  Ito et al


  Damage to this area reduces the ability to solve problems and organise thoughts

  
  

  Also be involved in the perception of lies and deception (Ito)
• Occipital lobe

  Jibiki et al


  Visual info messed up

  
  

  Leads to misreading of facial expressions and emotions which could further lead to deluded thinking
• Wernickes area

  Plaze et al


  The where system allows us to differentiate between internal and external voices, this is one of the key aspects of auditory hallucinations

  
  

  ( why are the audio hallucinations bad)

  Combine it with the previous point about the deluded thinking.
• Neurotransmitters

  Dopamine hypothesis

  Started with amphetamines and cocaine which affect the dopamine release

  
  

  Also schizophrenics had high numbers of D2 receptors

  
  

  These are called dopamine agonists as they release excess dopamine and this also leads to schizo type symptoms

  
  

  Also L-dopa raises dopamine (its given to people with Parkinson's) this also lead to schizo type symptoms (Grilly)

  
  

  Also drugs that decrease dopamine transmission lead to a reduction in symptoms

  (Dopamine antagonists)
• Revised dopamine hypothesis

  Davis and Kahn

  (Patel support)

  Positive symptoms are due to an excess in the mesolyombic pathway

  
  

  Negative symptoms are due to a lack of dopamine in mesocortical pathways

  
  

  Patel used pet scans to assess levels of dopamine in the dorsolateral prefrontal cortex ( schizophrenic people had lower levels)
• Evaluation of the dopamine hypothesis

  Leucht et al


  Leucht meta analysed 212 studies that analyses the effectiveness of antipsychotics and placebos.

  
  

  All the drugs had a higher effectiveness than placebo (treated the positive and negative symptoms)
• Evaluation of dopamine hypothesis

  Moncrieff (negative)


  Cocaine and amphetamines affect dopamines as well as many other neurotransmitters.

  
  

  Dopamine levels in post mortem studies have been negative ( goes against the hypothesis)
• Evaluation of dopamine hypothesis

  Noll


  In 1/3 of cases the antipsychotic drugs do not reduce the symptoms.

  
  

  Regardless of the levels of dopamine the symptoms were present.
• Psychological explanations for schizo

  Cognitive explanations

  Family Dysfunction
• Double bind theory

  Bateson


  Double bind theory is the view that parents that exert conflicting messages such as saying I love you to their child then turning away in disgust will lead to schizophrenia.

  
  

  May lead to future "flattening of affect" and "social withdrawal"
• Expressed emotion

  Brown et al

  Kuiper et al

  Lidz and Lidz


  Expressed emotion is the idea that a hostile environment may lead to relapse, for example parents always shouting and the individual and being disappointed and never showing love.

  
  

  Brown et al found that many schizophrenics experienced a lot of expressed emotions at home

  
  

  Kuiper et al- high EE relatives talk more and listen less. High levels of expressed emotion may lead relapse - a patient returning to a high EE home is 4 times more likely to relapse than a low EE.

  
  

  Lidz and Lidz- a mother who micromanages her child and doesn't acknowledge their independence
• Support for family dysfunction

  Tienari


  Those adopted children who had schizo biological parents were more likely to become ill themselves than those with non schizo biological parents.

  
  

  This difference only emerged when the adopted parents were rated as disturbed (only under the right environmental conditions the schizo arose)
• Support for double bind theory

  Berger


  Schizophrenics reported higher levels of double bind comments from their mothers than non schizo.

  
  

  However this could be unreliable as the schizo could be affecting their memory
• Negative criticism for double bind

  Liem


  Liem measured patterns of parental communication in families with schizophrenic child and non schizo and found no difference.
• Negative for EE

  Altorfer

  Lebell


  Not all patients with high EE relapse and not all with low EE avoid relapse.

  
  

  Altorfer sound that 1/4 of patients he studied showed no response to stressful comments from their parents.

  
  

  ( so may just depend on their individual vulnerability to EE) -Lebell
• Psychological explanations


  Cognitive explanations
• Cognitive explanations

  Perceptual deficits

  Memory issues