Idea Number One

The main character seems calm, collected and suspicious. The character is seen to be taking pills on a daily basis in which the audience knows no reason for. Over a gradual amount of time, the pills begin to work in a way that no other pill does, scary things start happening; lights flickering, turning on, sounds, alarm clocks going off, voices talking to them, paranoia. Nightmares are the final step. The main character soon becomes scared to sleep because if they do, they are took to the deepest most horrible place.

Possible Endings - 

The pills make her forget her trauma, the loss of her twin. It makes her only see herself when she looks in the mirror.

She is a schizophrenic.