contemporary study: Carlsson Flashcards
what was the aim of carlsson’s meta analysis
to review evidence for and against the dopamine hypothesis whilst aiming to include the role of other neurotransmitters e.g. glutamate
describe another neurotransmitter other than dopamine that carlsson suggested induced SZ
glutamate - it was found that ‘angel dust’ induces SZ symptoms and is a powerful antagonist of glutamate receptors. The effect is that glutamate is decreased, and this increases dopamine activity, acting as an accelerator.
explain what is meant by thalamic filter
thalamus associated with psychotic response, so can be turned on or off depending on which pathway is activated.
describe the two models of schizophrenia that the research review led to
hyperdopaminergic model - increase dopamine increases SZ symptoms
hypoglutamatergic model - this is an extension of the first model. Suggests glutamate can produce an increase or decrease in dopamine activity depending on whether accelerator or brake is applied.
explain the role of GABA in schizophrenia
glutamate releases GABA - this acts as a ‘break’ reducing dopamine activity. therefore, low glutamate may cause and increase or decrease in dopamine.
what is a strength of Carlsson’s research on glutamate antagonists?
low levels glutamate correlating with high levels of dopamine is supported by study carried out in mice who were given drug to decrease motor activity and given MK-801 which reduced glutamate and increases dopamine. This restarted motor activity, but continued use of MK-801 caused SZ symptoms. This suggests that SZ may be caused by glutamate irregularity.
what is a weakness of Carlsson’s conclusion? hint: animals
conclusions are based on animal models. Not generalisable to humans and their symptoms of schizophrenia. This shows that animal models fail to capture the more holistic experience which includes other people’s reaction to the symptoms.
what is a weakness of Carlsson’s conclusion: culture (Luhrmann et al)
Such research ignores the role of culture. Luhrmann et al showed cultural differences in experience of hallucinations. US pp more likely to hear violent and frightening voices whereas Indian pp had more positive experiences.
what is a weakness of the evidence for the dopamine hypothesis?
its based on people with SZ during acute episodes. People with chronic SZ may respond differently to drugs when they are between episodes. A person in remission is more likely to complain about the side effects of medication than during acute episodes. This means research needs to consider a wider range of phases of this disorder so can be more generalisable
How can Carlsson’s research evidence be applied to society
Carlsson’s focus on glutamate has led to development of new drug treatments e.g. glutamate agonists effective in reducing positive and negative symptoms of SZ. They are helpful for people who have been previously treatment-resistant and can be a good alternative.
