https://www.ncbi.nlm.nih.gov/pubmed/12467090
- That means the more 5 hindrances you have, the more handicapped your serotonin (bliss) levels are.It is likely that under chronic stress or depression, the capacity for increase in serotonin transporter has reached its limit due to the chronically elevated blood cortisol level.
- That means if you enter jhana, you have very very low levels of cortisol and higher levels of serotonin.
- That means you cannot stop stress with more stress (masochism, and simply observing dukkha), which is why the Buddha left the ascetics. You cannot stop fire with more fire.
- This is why right livelihood/lifestyle is part of the noble eightfold path, you are not going to enter jhanas if you have a stressful job (like killing animals/people) which raises cortisol levels.
Many people don't know what serotonin feels like, they mistake dopamine (addiction) for serotonin. Serotonin is a bliss you get from being healthy, dopamine is a short term addiction response and dopamine usually increases cortisol too, like say eating sugary junk food, this will increase dopamine AND cortisol.
But serotonin and cortisol are at odds with each other they handicap each other. This is why the Buddha said neither pleasure (dopamine) nor pain (cortisol) is the way. The middle way (serotonin) is the way.
So you are trading short term pleasure (dopamine) for stress (cortisol) which in the long hurts you and removes bliss (serotonin). Instead give up pleasure (dopamine) and pain (cortisol) and attain bliss (serotonin).
"Serotonin Receptor Helps "Turn Off" Chronic Pain""It has been known for some time that serotonin can modulate pain perception and the function of some drugs is based on this. Nevertheless, what is new in our study now is that we were able to identify a specific subtype of serotonin receptor that reduced the perception of pain more efficiently. This is an important result, which might help to treat chronic pain more efficiently in the future."
https://www.neurologyadvisor.com/pain/c ... le/406089/
https://www.medicalnewstoday.com/articles/291647.php