These are the people you have met in life's course who always complain about something but will find a reason not to look at solutions. When friends offer a solution, their first reaction is to find a reason not to try it. They are paralysed and can't move out of their unhappy comfort zone.
Without having made the choice to do this, without having personally decided that they want to become more positive, more inspiring and more encouraging, a person has no hope of ever conquering their own self-doubt.
My personal experiences are with people who say they are lonely but will always react with a reason why the actions suggested are not in their realm of 'possible' solutions.
We intimately prove the self-doubting limitation wrong, and eventually the mind learns a newer and more positive way of thinking about things, because it has witnessed firsthand the undoing of every single one of its limiting, doubting thoughts.
Under negatives, I would list what I am afraid of and what could possibly happen if I take that course of action. Under positives, I would list the good points that may happen if I take that course of action. I call this my balance sheet of life and have used it for things I found challenging. So it's similar to 'What's the worst that can happen?' and 'What's the best that can happen?'