When all sz be healers planet wil be happy and peaceful and healed
I would guess psychosis could hint at how brains construct this subjective simulated experience we possess, in same way brain lesions do. But it is true it is still very limited what is known how brains construct minds eye from moment to moment. Maybe the synaptic loss at frontal cortex and overactive midbrain in concert create this sense of hyperreal experience - after all brain is a sophisticated predictor of outer reality and psychosis could be malfunction of this system. But I must admit it is just a completely wild guess at best, nobody really knows at all. Considering human brain is one of the most complex known structure makes sense that any disease of this organ can be very mysterious indeed. Just not too happy being a specimen of said disease, not really no. 
My conclusion is that it’s a spiritual disease
Nothing is real.in this world everything is temporary