I don't think we are all victims of mass hysteria or hypnosis.
And let's talk further about a kind of objective data. Any of my intimates who are around me for any length of time come to be able to tell when I have had a bad exposure: my visage becomes puffy and sallow, deep circles under my eyes, I look 10 years older than my present-day 42 years, and simply ill. Anyone on the street to look at me would say, "That woman is sick. I don't know if it's cancer or hepatitis or AIDS, but something is very wrong." And since I have been getting better through my move to Santa Cruz, there are weeks when there is color in my cheeks and the pallor is gone and I routinely get mistaken for 30-something. I would have to have the mind-body powers of a Yogic adept to control such externally visible markers of where I am in an imaginary illness' cycle purely through neurotic whim.