Posted by Brainbeard on September 13, 2009, at 4:01:39
In reply to Re: Increasing SSRI/SNRI above the 'regular' doses » Brainbeard, posted by SLS on September 12, 2009, at 6:52:59
Sigma receptors were, when first discovered, thought to be a subtype of opioid receptors. Later it appeared they were in a class of their own. Not that much is known about sigma receptors, but the sigma-1 receptor appears to play a role in depression and anxiety. This is what emerges from animal tests and seems to correspond with the effects of AD's that affect sigma-1 receptors.
We know so little about sigma-1, that it isn't even clear wether either sigma-1 antagonism or -agonism (or both) provides relief from depression and/or anxiety. Fact is that Luvox (fluvoxamine) is a potent sigma-1 AGONIST. From what I know, at this point it isn't clear yet wether Lexapro (escitalopram) is a sigma-1 agonist or an antagonist. It is beyond me why noone instigates some research after this.
The reason that both Luvox and Lexapro can offer a more rapid therapeutic response than expected from the SRI-mechanism (i.e., somewhere in the first two weeks) is supposed to be their effects on sigma-1.
Even Zoloft (sertraline), by the way, is a weak sigma-1 agonist (its affinity for sigma-1 is stronger than its affinity for the dopamine receptor!)
SWSS, Prozac isn't the only SSRI with noradrenergic effects - Paxil (paroxetine) has significant effects on noradrenaline, as well as Zoloft on higher doses.
poster:Brainbeard
thread:916056
URL: http://www.dr-bob.org/babble/20090912/msgs/916825.html