Survivors hooked should have Madness 3 regress to 2
The Doctor is among my top 3 killers and I find very annoying the propentity to tunnel of most Doctor players. The reason they can keep up despite playing horribly is just one: survivors who just got unhooked are still in Madness 3 and are very easy to find.
I think if unhooked survivors had their Madness regressed to tier 2 good Doctors wouldn't be affected at all. I know I wouldn't. Also, it would maybe induce people to learn a bit more of the Doctor, who is not only the one "that makes people scream and easy to find".