Is schizophrenia genetic?
The table shows that it is more likely for someone to have schizophrenia if a first degree relative has it; especially if both of a child's parents are schizophrenic, there is also a higher risk of identical twins both having it. This implies that schizophrenia can be genetic, or that there is a hereditary vulnerability to it.
What is the Dopamine Hypothesis and how can it explain the major clinical characteristics of schizophrenia?
Some anti-psychotic drugs work by stopping dopamine activity and reduce the effects of schizoprehenia, but L-dopa (a naturally occuring vitamin like substance) can affect the activity of the brain and result in symptoms of schizophrenia in people who formly didn't suffer this, and weren't formly psychotic.
This has been shown in studies of things like amphetamines and LSDs which also affect the dopamine system; the findings from the studies were that these too caused symptoms of schizophrenia in people without it and that they can worsen symptoms in those vulnerable to it.
It has also been found that although anti-psychotic drugs have a positive effect on positive symptoms (dellusions, thought control, etc) they fail to do the same for negative symptoms (lack of control of body, lack of motivation and emotion, etc.)
Do you think Nash's case supports the idea that schizophrenia is a matter of nurture rather than nature?
Evidence has mainly shown that Schizophrenia is determined by nature; a genetic factor, but there are mainly explanations and approaches to looking at it. It's been shown that people can have a genetic vulnerability to schizophrenia. E.g. Parents having schizophrenia, and their children may be more likely to have it. However, as shown in a Beautiful mind; stress can have negative effects on the symptoms of schizophrenia and result in both them, and the delusions taking a stronger hold of the person suffering it.
Well done Nichola, first response to the task from anyone in the group. In your first part you mention hereditary vulnerability. The more conventional expression would be genetic pre-disposition but you've got the essential idea. Perhaps the most effective counter argument for a wholly genetically determined account of schizophrenia consists in the lack of concordance in slightly more than half of cases where the schizophrenic has an MZ twin. Clearly there is some genetic component in schizophrenia but there must also be an environmental dimension as well.
ReplyDeleteYour response to my question about the dopamine hypothesis shows you have found out some of the things we need to know about neurotransmission and drug therapies. However, you don't really state the hypothes. This will get clearer as we work on some of the underpinning neurophysiology. Thanks for being so prompt and working hard, see you soon, IGH.