"Psychosis" is a human variation, not a disease.
"This approach allows medicine to address a core paradox of the disease model of psychosis, a paradox demonstrated by van Os's research and countless studies from Europe, the US, and cross culturally: every "psychotic" experience — from hearing voices to paranoia to disorganized speech to strange ideas to manic bursts of inspiration to silent inward collapse — also appears in the "normal" population to some degree or another, without necessitating either distress or medical treatment. "Psychosis" is a human variation, not a disease. The "illness" is — again going back to the redefinition of health — the lack of capacity for adaptation and self-management in the face of challenges."
A New Mental Health System? An Interview with Jim van Os. / March 31, 2016.