Posted by Tomatheus on November 27, 2005, at 13:40:28
In reply to Re: where to get Serotonin Transporter gene testing?, posted by jamestheyonger on November 27, 2005, at 13:00:38
> I think if it walks like a duck and talks like a duck it should be treated as a duck. There is no need to test DNA to make sure it is a duck. Having a more specific Dx does not improve treatment in mental illness given how hard the meds are to tolerate and the fact that meds are non-specific.
You could not be more wrong. Consider this article:
http://www.nimh.nih.gov/Press/prprice.cfm
Among the facts reported in this article is the finding that some schizophrenic patients carry a genetic variant that produces abnormally high levels of the COMT gene and actually respond to favorably to amphetamines. COMT is an enzyme that is believed to destroy dopamine and norepinephrine in the synapses. If psychiatrists followed your logic and treated these schizophrenic patients simply as schizophrenics, they would likely prescribe antipsychotics, most of which (among other things) reduce the effects of dopamine by blocking dopamine receptors. The problem with this is that a person with abnormally high levels of COMT is going to have abnormally low levels of dopamine, not too much. Theoretically, most antipsychotics would only make these patients worse. As I said in my previous post, psychiatrists should definitely consider factors other than the results of genetic tests. But if a psychiatrist knew that a given schizophrenic patient had this variant of the COMT gene, this would at the very least give the psychiatrist some clue as to why antipsychotics might make this patient worse (as they often do with certain schizophrenic patients). Even if the psychiatrist prescribed an antipsychotic as the first line of treatment for this patient, he/she might want to consider a medication with a different mechanism of action (in this case, possibly amphetamines, given the results of the study in the article I linked to) if the patient gets worse on the antipsychotic. As a result, patients could end up receiving effective treatment early on instead of receiving nothing but the wrong meds for the rest of their lives.
> Another issue is meds do not treat the cause of mental illness, they treat the symptoms.
Can you be so sure of this? Perhaps the most commonly accepted model for explaining the causes of mental illnesses is the diathesis-stress model, a theory that holds that both genetic and environmental factors interact with one another to cause mental illnesses. Even if a genetically determined biochemical imbalance is only part of the cause of a given mental illness, this imbalance is more than just a symptom. For patients whose depression is caused - at least in part - by the genetic variant encoding for abnormally fast reuptake of serotonin, do SSRIs not treat the cause. For schizophrenics whose illness is caused in part by abnormally high levels of COMT, would a COMT inhibitor that successfully inhibits the right amount of COMT not treat the cause? For someone with major depression whose illness is caused by an abnormally high level of MAO-A, would an MAOI that successfully inhibits the proper amount of MAO-A not treat the cause? Seriously, how can you be so sure that meds never treat the causes of psychiatric illnesses?
Tomatheus
poster:Tomatheus
thread:582481
URL: http://www.dr-bob.org/babble/20051126/msgs/582705.html