There are many people who have depressive issues/stressors...and they typically crave carbohydrates. Even Oprah (who I don't like to quote really) says mashed potatoes are one of hers.

That is one issue.

Then there is the issue of consuming a large % of calories at one meal only in carbs. Statistics show that only about 25% of people can handle this. Have stable insulin responses. 75% cannot. I'll never forget the day my son's roommate came on vacation with us for 2 wks. For breakfast he ate 1/2 box of cereal. ( I was not prepared for this on an island 13 miles from a mom and pop grocery). And he was THIN...and we just stared at him A box of GF cereal lasts me a month sometimes. In fact if I can't sleep, I'll have some at 2am and it is guaranteed to put me back "out". We eat protein for breakfast in contrast. But this response is not the same as the depression question posed here.

A large carbo meal (pasta, grains, sugar) will sedate most Americans. This is because a huge insulin spike occurs and that leads to sleepiness.
Being sleepy is not the same as being "depressed".

One side effect of the Atkins diet...high protein/high fat was to create an alert response. In fact it made some people downright mean!