'"So... so, I'm crazy, right?"
Twilight answered him with a question of her own. "The voice isn't telling you to hurt anypony, right?"
"And you know it's coming from you, right?"
..."Spike, I know you aren't crazy.... I had something similar happen. I, um, spoke to Princess Celestia about it afterwards, actually. Yes. Princess Celestia explained that sometimes when we have a little, negative voice like that in our heads, it doesn't mean we're crazy. As long as we know it's ours and we aren't being told to hurt anypony, it's not crazy."' - Anxiety, Bad_Seed_72
Dr. Twilight: You don't meet the diagnostic criteria for Schizophrenia.