Your brother may be experiencing mental defeat. This is a common response to chronic pain. The person starts to see pain as an enemy out to get me. They start to feel less than human. They may even say the pain is taking over.
Chronic pain and loss can trigger negative beliefs about self in relation to pain. The person may experience a loss of control leading to a sense of helplessness.
But when they lose their sense of identity, then helplessness turns into hopelessness. Repeated episodes of uncontrollable pain can wear away at a person’s ability to cope. Mental defeat starts to creep in and may become full blown.
Referral to a licensed counselor, psychologist, or psychiatrist may be appropriate. If your brother has anxiety, depression, or other mood disorders, then medication can help. Cognitive behavioral therapy (CBT) is a method of counseling that can also help patients redirect negative thoughts.