Synthetic feeling of wellness
I read that the 28 or 33 amino acid peptide Orexin-1 is what causes people to feel unwell when some other cause is actually a source of illness. http://www.jneurosci...60-458b083c87f7 Thus drugs or genetics that vary Orexin-1 response could make a person feel well all the time regardless of their physiological state. At the developed world most illness is absent immediate risk, so people should cetrtainly feel super well, even while they are ill.
I think it is wonderful that regardless of what ails them, people can feel well. I am particularly thrilled at finding gene variants of orexin that create higher sustained feelings of wellness regardless of physicality. Persons with these genes would always feel well regardless of what was occuring.
The OHSU med research promotional material I found that mentioned this vaugely suggested to me, without naming a specific chemical, that modafinil like chemicals could cause artificial wellness. That is because the Orexin neurons are also the neurons thaty respond to sleep tiredness with modafinil responsive neurons.