Posted by Quintal on February 21, 2007, at 17:45:07
In reply to Re: opiates for depression, posted by linkadge on February 21, 2007, at 16:02:22
>I don't think it is fair at all for somebody to say that anyone using opiates for depression is merely chasing a high.
I agree. I'm not sure to whom this post was directed, if anyone in particular, but I'll respond anyway........
>It is just like how drugs for ADHD are not treating ADHD *by* causing euphoria. Euphoria is simply a side effect. The theraputic effect is not due to dopamine release in the neucleus accumbens, but rather dopamine release in the frontal cortex.
I think it's hard to tell link, since there are no drugs that specifically release dopamine only in the frontal cortex (that I'm aware of) that could prove it conclusively. The performance of treatments for ADHD that operate selectively via the noradrenergic system, like Strattera seem less impressive than those that (perhaps incidentally) increase dopamine release in the nucleus accumbens. I think to some significant extent the increased efficiency and tolerability of amphetamines used to treat ADHD is due to increased desire and greater capacity to feel reward caused by release of dopamine in the nucleus accumbens, as well as increasing attention span and organisation etc, by releasing dopamine in the frontal cortex. I say this because again, drugs that increase attention span alone and cause little if any euphoria, like Strattera seem to be less effective (and less well tolerated) overall.
I really think a drug that's subjectively more pleasant in its effects will have more treatment responders, because more people will be willing to persevere for the full length of the trial even if the actual benefits aren't that good.
>Similarly, I think it is possable that opiates do something in addition to their abuse poetneial. There is a link, for instance between depression and pain. Opiates affect the activity of substance P for instance. Substance P inhibitors are being investigated as a means to treat depression without euphoria.
I'm sure you know opiates affect many chemicals in the brain link, most of the usual mood-altering culprits dopamine and serotonin for example, as well as any action on substance P. We already have a whole gamut of antidepressants that supposedly treat depression without causing euphoria. They seem to be less effective overall than those that do cause euphoria, especially for treatment resistant depressives, and that is what most of this debate has been about.
That reminds me, didn't the legendary Elizabeth of Buprenorphine disappear off babble radar right after announcing she was considering being a participant in a clinical trial for a substance P blocker? I wonder if she ever did attend? Ominous.
Q
poster:Quintal
thread:734151
URL: http://www.dr-bob.org/babble/20070219/msgs/734915.html