"Mmm..." Erin wobbles her hand. "It can? Some people are born psychotic, others develop it through trauma. Many people will experience psychosis temporarily for various reasons - a good blow to the head, drugs, extreme grief or stress. My people, we're just like this whether we were before or not, though the trauma certainly doesn't fucking help. We don't respond to medicines meant to treat these symptoms, but that's, y'know, my soul's fundamentally damaged, there's no pills for that. Conventional humans sometimes respond better to treatment, depending on the cause."

She pauses. "...Am I describing something you experience yourself, Dedue?"