Answer: Learned helplessness
Step-by-step explanation: Learned helplessness is the mechanism in which an individual believes or is aware about the that he/she will not be able to escape from the painful or unpleasant situations or environment because they have no control over the events or stimuli.Thus, the person is aware about the his/her helpless situation.
The situation mentioned in the question states about the learned helplessness of Nathan. Mental condition of Nathan has become serous issue because of the unpleasant events happened in his life .