Posted by SLS on September 27, 2006, at 7:19:21
In reply to Re: genetics of schizophrenia, posted by alexandra_k on September 27, 2006, at 5:23:36
> The term 'gene' is ambiguous.
I think it tends to be used in two ways. In one sense a gene is a combination of allels. (Is that right?). But in one sense the notion of a gene is a localised part of a chromosome. In the other sense the notion of a gene is more abstract... Something along the lines of a placeholder for whatever allels.
Yes. I guess the word "gene" should basically be defined as a coding unit. It is also often used interchangeabley with the term "allele".
> If you talk about the 'schizophrenia gene' you might mean that there are a bunch of allels somewhere on the chromosome and however those allels are is necessary and sufficient for schizophrenia.No, not me personally.
> Or you might mean that surely people must develop schizophrenia because of the way their allels are... And the 'schizophrenia gene' can be multiply realised by all kinds of allels at all kinds of locations.
I really am not on top of the research regarding which chromosomes and which loci are currently suspect as being associated with schizophrenia.
> Griffiths talks about 4 (I think) different meanings of innate (in the sense of genetic versus environmental). He doesn't think we should talk about things being genetically determined / innate because the way genes express is dependent on the environment. He distinguishes 4 things we might mean (of varying strengths).
>
> I can't remember what they are...Shame on you.
> I'm tired.
> I'm sorry.I know. You have to work in all that heavy air there down under.
> I don't really know anything about genetics / biology
> But I guess I'm gonna have to learn...No, actually, I think you know enough. I wish I were as well educated as you.
I think it might be more instructive to follow some pedigrees and twin studies. The twin studies will help support the types of ideas regarding the possible necessity for environmental contributors in the induction of schizophrenia, although I would not rule out congenital factors during gestation. Psychosocial stress is undoubtedly at work. Damn it.
Similar studies are available for bipolar disorder. Elliot Gershon has done much work on this. I believe he was one of the contributors on the work with the Amish community.
Depression is another matter. The word is just too big. Even the diagnosis of Major Depressive Disorder as defined in the DSM is too broad to sequester genetically based biological phenomena. That is not to say that other types of depression, both biologically-driven and psychologically-driven, could not benefit from biological treatment. However, it would be nice to be able to separate out people who would be best suited for biological versus psychological therapies, so as not to frustrate the sufferer with treatments that are not likely to work, and thus sabotage their spirit. Of course, there is a large area of overlap, as the brain and mind are inextricably linked. It is reasonable to conclude, and it has been demonstrated through clinical investigation, that concomitant biological and psychological treatments can act synergistically to enhance one's chances of recovering from depression. Depression is often not an either-or situation.
- Scott
poster:SLS
thread:689461
URL: http://www.dr-bob.org/babble/20060927/msgs/689544.html