Posted by Conundrum on January 9, 2011, at 12:29:18
In reply to can anyone explain dopamine's role in depression?, posted by floatingbridge on January 8, 2011, at 22:48:40
Hi FB,
while it is true at this dose that emsam at 6 mg effects dopamine more than any other neurotransmitter, its effect on mood is limiting. This is because it is MAO-B selective in certain regions of the brain that are not effective for enhancing ones mood.
There is a lot of incomplete information out there about MAOIs. Unfortunately most psychiatrists don't do a good job of explaining med functions to their patients, so we are left to try to figure this one out on our own. So both MAOA and B inhibition increase dopamine, but do so in different parts of the brain. MAOA inhibition will increase dopamine, along with norepinephrine, and serotonin in areas that help with the relief of depression. MAO B inhibition can help with parkinson's symptoms. Pure MAO-B inhibitors have not done well as antidepressants and that is the reason you need to take 9-12 mgs with emsam to get a good response, because it starts to lose its selectivity for MAOB and inhibits MAOA as well.
http://www.evetopf-center.org/Articles/Art_10042006152324.pdf
This article talks more about the difference between MAO B and A and also gives list of many MAOIs that are currently in use(about half way down). As you can see the ones that are used as ADs have MAO A inhibition or A with B, but the selective MAOB inhibitors are all parkinson drugs.
The role of dopamine in depression is difficult to pin down, because most drugs that effect dopamine effect other systems, and even a drug that is selective for serotonin like lexapro, will have an effect on dopamine.
That being said there are plenty of drugs that don't work on dopamine and plenty of drugs that do, so by process of elimination you can kind of guess what effects it has. It seems to be important for wanting to do things and drive(not necessarily liking), it also, seems to be important for social comfort, this is part of the reasons MAOIs are especially good for social anxiety. It is important in cognition and concentration. It seems to be important in reinforcing addiction and too much can cause one to become paranoid and delusional. That shooter in Arizona would probably have benefited from a drug that blocks dopamine.
So if you are having problems with concentration, anhedonia, social anxiety MAO A inhibition might be the way to go, but then you have to follow the dietary restrictions.
> I know I've asked this before in some form or another.
>
> My depression is worsening. I ran across information that stated emsam at 6mg affects dopamine levels more than other transmittors. (Maybe true?)
>
> The last time I repeated what two docs said to me, I was (kinda) ridiculed. They said I was a dopamine responder. I didn't and don't understand enough to know why this could be considered absurd.
>
> Can one be low in dopamine? Not processing it efficiently?
>
> Is it related to endorphines?
>
> Thanks for any clarification or for pointing me towards some reading.
>
> fb
Complaints: post-SSRI problems: anhedonia, memory and concentration problems, sexual anhedonia. )
Country:USA
Currently taking 2.5 mg prozac, Multi B vitamin
poster:Conundrum
thread:976260
URL: http://www.dr-bob.org/babble/20101231/msgs/976324.html