Posted by Randal on August 18, 2002, at 15:27:54
In reply to Re: Genes PLUS environment: Environment?? « jay, posted by Dr. Bob on August 18, 2002, at 8:50:34
Jay,
Since you bring up diabetes, I'll use that as an analogy. Type I diabetes is an autoimmune disease and clearly has a strong genetic component. If one identical twin has diabetes, the chance the other will is 50%. The rest of the 50% is then due to "environmental" causes, which in this case are probably things like viral infections that set off an immune response. Can SYMPTOMS of the disease be set of by what we would normally consider environmental factors? Certainly diet can play a huge role. Does this mean that the "environment" as it is interpreted by most people for psychiatric disorders can "cause" the disease? I don't think there is any evidence for this. Do doctors tell parents of at-risk children to provide a stable family life so their kid won't get diabetes? I hope not.
Type II diabetes also clearly has a genetic component (as a quick example, women who tend to distribute fat in their upper bodies are much more prone to the disease than are "pear-shaped" women) In this case I'm sure you CAN probably make a strong argument that "environment", most likely diet, exercise, etc. does play a role in "causing" the disease in the context of a genetic predisposition. Rates of type II diabetes, along with obesity have increased dramatically over the last several years, presumably largely due to such factors.
I am concerned that we simply assume psychocial factors are the MAJOR influence that is not purely genetic, when it is not clear to me that they play a significant role. Many psychiatrists use to think that all mental illness, including the real hard core ones like schizophrenia and bipolar I disorder were caused ENTIRELY by psychosocial factors. Only recently has it been shown that this is not the case.
So are we just holding on to mistaken beliefs from the past? My impression is that for schizophrenia the balance has shifted far, far in the direction of biological causation. Is this true for bipolar disorder as well?
Randal
> [Posted by jay on August 18, 2002, at 4:13:44]
>
> >
> > Hi:
> >
> > I understand your frustration with the Nature/Nurture concept...and you certainly aren't the first to be so.
> >
> > The interplay between 'environment' and genetics is still far too complicated for us to have lengthy, absolute answers on. In the book 'The Noonday Demon', the writer Andrew Solomon(sp?) gives a good example. He was talking to a psychiatrist whose wife was an endocrinologist. The P.Doc's wife treats many kids for diabetes in which many of them come from poor and lower-class families. Of course, those kids live with the stresses that poverty can bring to a family, which can also shoot the kid's blood-sugar levels way out of whack...hence the susceptibility to diabetes. (This is a paraphrase from the book.) I have also been reading a fair bit lately about child diabetes and psychological state. It's very far from being some exact 'theory'..but it gives us something more to think about.
> >
> > OK..hang with me here. Levels of ADD and Depression also seem to be greatly impacting wealthy, as well as 'stable family' (and the two are *not* exactly co-related) children. Many don't have to face going a day without a meal, or feel the stress between parents having an argument over how to spend the last 15 dollars they have that week. (Again..please understand...I know "wealthy" parents argue..and many are dys-functional..etc.) I am sorta using a bit of a wide stroke here, but can you see where both Nature and Nurture can predominate?
> >
> > I hope that makes sense...
> >
> > Thanks,
> > Jay
poster:Randal
thread:28868
URL: http://www.dr-bob.org/babble/social/20020813/msgs/28882.html