Brady has schizophrenia. he seems to have no interests and lacks the desire to do anything. he takes little pleasure in any activity. brady's absence of normal behavior exemplifies the typical of schizophrenia.

The absence of normal behavior exemplifies the Negative symptoms typical of Schizophrenia.
Negative symtoms refer to the type of symtoms that is caused a certain withdrawal or dismissal to something that usually exist within the patient. (in this case, Brady is experiencing dismissal of his emotional pressure and interest due to his illness)