indeed people that consume mushrooms are happier... But psilocybin doesn't block the receptors of sadness, actually there's no such thing... Sadness is the result of absence of the neurotransmitters of happiness (dopamine, serotonine & oxitocine)... And this is a complex chemical world inside of us... What psilocybin does is stimulating the connections in the brain, helping a person to overcome mental loops that keep them stuck on bad feelings. So anyway you end up happier just because is the natural way of the humang being to be happy =D