biological - structural abnormalities

• What did Kraeplin classify scz as?

  an organic brain disease, that was partly biological due to brain scanning technologies identifying scz.
• what are enlarged ventricles?

  - are cavities that produce and transport cerebrospinal fluid

  
  

  - cerebrospinal fluid is important as it provides protection/bouncy for the brain and spine

  
  

  - believed that large ventricles are a sign of scz
• how many ventricles are in the brain? and where?

  - left and right ventricles (frontal lobe)

  
  

  - third ventricle is situated between the left and right thalamus

  
  

  - the fourth ventricle which lies between the pons and medulla oblongata
• what did Daniel Weinberger do and find?

  do

  
  

  - used CAT scans and reported that ventricular size was greater in a group of 58 individuals with chronic scz than in the 56 controls who had no symptoms of scz
• what did Nancy Andreasen do and find?

  - studied MRI scans of people with/without scz

  
  

  - found that those with scz had ventricles which were 20% to 50% larger than in controls
• what is an additional finding for enlarged ventricles and scz?

  it didn't matter for how long they'd suffer from scz, nor was it related to the type of medication they were taking
• what do you think might explain larger ventricle size in patients with scz?

  - brain ventricles enlarge when damage occurs (neurons are destroyed, ventricles enlarge to maintain pressure in brain)

  - in scz, brain damage occurs
• what is cortical atrophy?

  - loss of neurons in the cerebral cortex

  
  

  - can occur all over the brain (shrunk brain)

  
  

  - affects the cognitive functions

  
  

  - the damage appears to characterise the brains of 20%-35% of people with chronic scz
• what did Vita et al 1988 do and find?

  do

  
  

  - used CAT scans to assess 124 people with scz and 45 control group ppts.

  
  

  found

  
  

  - they found that 33% of people with scz showed moderate to severe atrophy

  
  

  - atrophy was not found related to many individual differences such as age but related to sex if there was a ventricular enlargement
• scz brains suffer a loss of volume, what is being lost?

  - fewer neurons (brain cells)

  
  

  - or, a reduction in connections between neurons (Feinberg)
• how might cortical atrophy explain the increased ventricle size?

  if the brains of scz people have lost volume (cells or cell connection), the ventricles would have to enlarge to maintain pressure
• what is reversed cerebral asymmetry?

  when the right hemisphere is bigger than the left, this indicates scz e.g. language function is found in the left hemisphere so damage to this can lead to algolia (poor langauge)
• what did Daniel Luchins do and find?

  do

  
  

  - compared using CAT scans, 80 right handed people without scz to 57 right handed people with scz

  
  

  found

  
  

  - increase in the frequency of reversals in bith frontal and occuipital lobes of those with scz (but only in those with no other form of atrophy)

  
  

  - those individuals with scz who had evidence of atrophy had no higher levels of reversals than the control group
• is scz neurodegenerative or neurodevelopmental?

  we need to look at lontitudinal studies, e.g. Oblai
• what did Oblai do and find?

  do

  
  

  - conducted a meta analysis of longitudinal studies of schizophrenics

  
  

  find

  
  

  - they found that the illness of scz showed a clear progression, and brain volume decreasing over time
• what does research suggest scz is?

  neurodegenatitive
• what did Chan et al find?

  those at high risk for scz have smaller brian volume and enlarged ventricles, before even showing symptoms of scz.
• Evaluation of enlarged ventricles

  - structural abnormalities can be found in individuals with different conditions, not only found in scz

  
  

  - Paul Roy; individuals diagnosed with bipolar disorder and schizoaffective disorder have also been found with enlarged ventricles

  
  

  - certain disorders have overlapping symptoms which can make sense of similar structural abnormalities

  
  

  HOWEVER

  
  

  - these disorders may have similar caustion or that perhaps we have classified these different conditions need to be reviewed
• evaluation - cause and effect still unclear

  - if structural abnormalities cause scz, what caused the abnormalities?

  
  

  - where did the scz come from if structural abnormalities were caused by scz?

  
  

  this theory cannot explain why the illness seems to run in families
• evaluation - scz biological evidence

  - lots of evidence that scz is biological, runs in families

  
  

  - responds well to bio treatments
• what is neurodevelopmental?


  parts of the brain arent developed, due to genes, changes in brain cause scz
• what is neurodegenerative?


  few brain changes at start of an illness, progressive, gets worse over time