To quote that article:
Buprenorphine reduces the patient's response to stress by blocking a receptor in the brain called the kappa opioid.
However it also stimulates a related receptor called the mu opioid, which could cause addictive effects if taken long term or used by depressed patients.
To counter this, the researchers used the anti-addiction drug naltrexone, which blocks the mu receptor. They found for the first time that in mice this combination gave an antidepressant effect.
Dr Bailey added: "Our study shows that using a combination of naltrexone and buprenorphine gives an antidepressant effect in mice, but without the problems of addiction that could be caused by using buprenorphine alone.
This is an interesting approach. It seems that to get the antidepressant effects, the goal is to block the
kappa opioid receptor, but without agonizing the mu
opioid receptor.
Though there is already a similar combination drug on the market called
suboxone (a combination of buprenorphine and naloxone), which is taken as a sublingual tablet, and sued by some ME/CFS patients on this forum. Naloxone and naltrexone have very similar effects.
Another possible approach might be to take the supplement
amentoflavone, which is a kappa opioid antagonist. Amentoflavone is found in ginkgo biloba, but can also be bought separately.
Hesperidin (found in orange juice) is also a kappa opioid antagonist with apparent antidepressant effects.
1
I found
this forum post about the anti-anhedonia effects of kappa opioid antagonists interesting. To quote this post:
Kappa opioids are THE cure.
Key areas are kappa opioid involvement in fear response, notable fear memory recall and storage. They opose the reward "mu" opioid, they are the other side of the medal.
A few highlights:
1. Kappa opioid agonists at higher doses cause fear, anxiety, depression and anhedonia - directly and rapidly without any other effects. No other chemical does anything remotely similar.
2. Kappa opioid antagonists stop fear anxiet and depression and restore hedonia directly and rapidly without any other effects(such as sedation or euphoria). No other chemical does anything remotely similar.
3. Kappa opioid antagonists RESTORE normal mood. You can not get high off them. Mu opioids are for getting high. Kappa opioids are the oposition - the inhibition of reward. They can only go so far as to disinhibit.
4. Kappa agonists are the only known chemicals that REVERSE drug tolerance. To ALL drugs. Tolerance is infact the kappa opioid network tone. When consuming drugs the high dopaminergic state causes kappa opioid network upregulation to compensate and reduce all this dopamine - this is development of drug tolerance. To counter it you need to hit the kappa opioid receptors instead of mu opioid. The body will not restore this balance back any time soon as drugs users painfully know.
Here's a very throrough study that is pretty much scientific but there are some animal examples that are easy to understand.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2787673/
There is a cure but it has been hidden for years by the fact that Mu opioid receptors are the pleasure ones and cause addicitions and thus the kappa opioids were ignored as well.... thruth is, even natural substances that agonize mu receptors usually antagonize kappa... it's the fear/reward -approach/avoid system. And all these years they only thought of it as rewarding and painkilling. While infact pushing kappa receptors causes bad feelings and fear.