How has Peeta changed throughout Mockingjay
From the beginning of the book,there is a shift in the relationship between Katniss and Peeta as they are separated from each other. During Peeta's appearances on television he seems to be reaching out to Katniss to get her to change her mind about the revolution, but the reader isn't sure if it is his words or the Capitol speaking through torture. Clarity finally seems to come when the old Peeta, selfless and protecting, warns Katniss through a live interview that she will be "Dead by morning" (133). His words draw the wrath of the Capitol as he is beaten and "his blood.. splatters on the tiles" for all to see (134).
Peeta is rescued from the Capitol and all signs point to a happy reunion with Katniss until Peeta seizes her throat and tries to kill her. This unexpected turn of events was the result of a "hijacking" attack on Peeta's psyche in which the government used tracker jacker venom to poison his memories of Katniss to the point that the girl he loved and pledged to protect was no more than "A mutt... a stinking mutt!" (198)
The medical team at District 13 does everything its power to help Peeta, but he never fully recovers. In time Peeta and Katniss "grow back together", but there are still times when "he clutches the back of the chair and hangs on until the flashbacks are over" (388).