> Sugar withdrawal can be modestly severe, but it's not physiologically habituating, and a couple of weeks of abstinence will get you through the worst of it.

Simple carbs spike serotonin levels, and then collapse them soon afterwards. People want to feel good, so they eat more sugar, which leads to another spike. This is by definition addictive!

It is also a vicious cycle. Too much sugar consumption can lead to obesity, which can then lead to depression, and of course sugar is already a person's go to treatment for feeling "down".

Thus the cycle continues.