You didn’t have anywhere to go.
Your family was gone, you were expelled from med school, No home, no friends, no relatives or anything.
Sam and Dean had found you in your family home, surrounded by the bodies of your family, claiming what had killed them still lingered, but wouldn’t touch you.
Naturally you were the prime suspect, and your sightings didn’t help with the fact that the police already thought you were insane.
When the demon that killed your family was gone, and Dean and Sam managed to clear your name, the damage was already done. You couldn’t stay, and you sure as hell would’ve been as good as dead if they hadn’t realized your usefulness.
You didn’t just sense otherworldly things, you could see them. Long before Sam and Dean could, and long before they struck. Dean called is Clairvoyance, you called it a curse. Either way there was no way they’d leave such a helpful asset behind, especially with your medical knowledge. Not to mention you were easy on the eyes.
Rockford Illinois was gloomy, but to you, you could sense the energy miles before they got there. It was angry, and festering. The Roosevelt Asylum was swarming with that same energy.
You had been nonstop pacing in the motel room, a lingering sense of dread settling in your stomach. Sam was in his own room, all cause of Dean. Cheeky bastard.
“Are you gonna talk about what’s bothering you or just keep pacing like an idiot?”
He said as he walked out of the bathroom, interrupting your panic.
“Well? What’s got you so worked up huh? I mean we ain’t even at the damn asylum and you look like you’ve seen a ghost.”
He actually laughed at his own damn joke.