One explanation is poor evaluation of evidence in their environment and matching their past to their present environment. CBT deals with this. A black and white way of thinking will lead to poor reasoning and misguided emotions for their environment. Like a conspiracy theorist will distort evidence and confuse the probabilities of unlikely events. They will take weak evidence and deduce distorted statements about the world
That's quite probably a high factor indeed. I often felt like the value of social groups is to smooth out emotions. When you're with people you are a lot less stuck in your own mind and somehow you don't pile up negative thoughts to the point of crippling darkness.
Also something I've noticed when trying to meditate (just cleansing my mind, nothing fancy). You can stop thinking and in a few minutes you'll feel just a little upbeat feeling, maybe fun ideas.
It's a bit odd and paradoxical but your best choice is not to listen to your negative ideas..
Actually evidence shows that depressed people are more realistic about the world than non-depressed people. The converse is true as well: people with unrealistically high ambition tend to do far better than those with realistic views.
I view it as a probability spectrum. Prior default 10% this, 90% that... if you don't do anything you get that 90% outcome.. but you can act!!! And that increases the likelihood of the 10%. This means you need to apply Bayes Law to your thoughts. It also explains reality distortion fields etc...
