I'm sitting here, watching The Golden Girls. It's one of the episodes that's hardest to watch--you find out that Rose (for those that don't know, Rose is a Minnesota farm-girl, totally innocent and a huge sweetheart) has been taking prescription painkillers for thirty years.
It's painful to watch, because everyone loves Rose, and it just comes as a shocker when you find out she's been taking these drugs. Aside from the fact that such a heavy issue has been dropped on the sweetest, kindest character of the entire series, it makes you re-evaluate her entire character: is that why she's been so happy this whole time?
That's perfectly pointed torture to a 'T,' and it's incredibly useful. Take a look at another example: Severus Snape from the Harry Potter series. He loved--true, deep, everlasting love--Lily. but, when all's said and done, she marries James Potter, the one man he can't stand, his personal tormentor fro, his school days. Fast forward a few years and they have a son. Then they die. Their son, when he grows up, looks exactly like James, except for Lily's eyes. He's also under constant threat of death from a horrible, dark wizard. When it comes down to it, their son is thrust into Snape's life. He's torn between hating what of James is in Harry and his love for Lily, and thus her son.
Torture: as far as writers are concerned, torture is a good thing. Room 101 is even better. Find the one specific torture that will break your character, that will infiltrate every second of his or her life, and pile it on. Thick. As my high school band director would say, use more peanut butter. Of course, we're talking more like cyanide butter, but the metaphor still stands.
Off to go oil the iron maiden,