I suffer from depression (it's now controlled by medication but they unfortunately contribute to weight gain) but I was told by my doctors that many people eat carbs when they are upset. Carbs affect the level of serotonin in your brain and serotonin is one of the chemicals that affects "happy signals" (see how I'm using technical language?? lol).
I know when I was depressed the first things I would reach for to eat would be bread, pasta or buttery mashed potatoes (oh...mashed potatoes are my achilles heel....).
I'm not sure of the exact science behind carbs and serotonin but at least now you know there IS a scientific reason for it. :o)
I will always be able to find reasons why I CAN''T do something or excuses for why I won''t be successful. Sometimes, the best thing I can do is make myself stop thinking, and just forge on ahead regardless.