Carlson-contemporary

Question 1

Carlson aim

Answer 1

• To see if neurotransmitters, other than dopamine, were implicated in causing
  Schizophrenia and to establish the role of glutamate in causing Schizophrenia.
• To test the role of Neurotransmitters in Schizophrenia with the aim of looking at the
  effectiveness of, and issues with, the current drug treatment of Schizophrenia. This
  was done to see if new drugs could be more effective, with less side-effects.

Question 2

carlsson sample and method

Answer 2

32 studies were reviewed including:
* Studies of rodents and primates to test neurotransmission
* Studies that carried out brain structure scans
* Studies of individuals on amphetamines
* Studies of individuals on PCP
* Studies of patients prescribed medical drugs for SZ
* Parkinson’s patients
* Studies looking at acute Schizophrenia and Schizophrenia in remission

Question 3

Carlson results

Answer 3

• The Dopamine hypothesis is likely too simplistic. There are other neurotransmitters
  which relate to Schizophrenia; Noradrenaline, Serotonin, Acetylcholine, Glutamate
  and GABA.
• ‘The change in dopaminergic function may even be secondary to aberrations
  elsewhere’ suggesting it is alterations to other neurotransmitter levels causing the
  changes to dopamine levels.
• At this point it is difficult to choose between the two major pharmacological models
  of schizophrenia; the hyperdopaminergia model, and the hypoglutamatergia model.
• Low levels of glutamate have been shown to be linked to the development of
  psychotic symptoms (Moghaddam & Adams 1998), suggesting when we have reduced
  Glutamate, Dopamine levels rise.
• NMDA antagonists seem to stimulate the turnover of serotonin more ‘consistently’
  according to Carlsson and so Serotonin may also be implicated in Schizophrenia too.
• ‘Glutamate failure in the cerebral cortex may lead to negative symptoms, whereas
  failure in the basal ganglia (cognition, co-ordination and movement) could be
  responsible for positive symptoms’.

Question 4

Carlson conclusion

Answer 4

• Clozapine is seen as highly effective in treating Schizophrenia with a reduction in
  negative side-effects, particularly because the drug has both antidopaminergic and
  antiserotonergic functions.
• New drug treatments need to be developed, focusing on increasing levels of
  glutamate.
• Some individuals may need drugs that target dopamine levels, other individuals may
  need drugs that target glutamate levels.