- Why do dementors attack Harry during Quidditch?
- Do the dementors attack Harry because he is a horcrux?
- Why was Sirius Black not affected by Dementors?
- Why is chocolate good against dementors?
- Why did Remus keep giving Harry chocolate?
Why did Umbridge send dementors to attack Harry? She sent them to assassinate Harry (technically Soul Murder him). And she did that for a couple of reasons. In OotP she intimates that it is because Harry was making the Ministry look bad for not admitting that Voldemort had returned.
Harry is an “accidental horcrux”, created when the killing curse casted by Voldemort backfired, fragmented his soul, and sent a piece of it to Harry’s body. This theory adds that Harry blacking out after every Dementor attack could have been because it was the piece of Voldemort’s soul which was in really bad pain.
Since Dementors can not properly sense the less complex thoughts and emotions of a person when he takes on an Animagus form, doing so allowed Sirius Black, to temporarily avoid feeling the effects of the Dementors’ presence.
It is possible that chocolate is used to ward off the effects following meeting a Dementor as it has chemicals inside it that stimulate the release of endorphins, which are chemicals produced by the body to combat stress and pain, often leading to feeling of increased happiness.
Remus Lupin carried chocolate with him on the Hogwarts Express and gave Harry Potter some after the latter was attacked by a Dementor. Harry Potter later commented that he never wanted to eat a piece of chocolate for a while afterwards, as he apparently has grown sick of it for a while.