Why do you think it's because of CBT?

But I have this too. I used to have a strong opinion, I would care about what happens in the world, etc. Now I just don't care. I can't help it. If I see something bad on the news, I have no reaction at all. I do think it's bad, but other than that I don't care, I don't feel anything about it. But I think it's because of the depression.