In fact, chocolate is one of the most commonly craved foods in the world. Seratonin and dopapine may be involved in chocolate cravings. These are chemicals released in the brain that act on the centers of the brain that deal with emotions, cravings and addiction. That's why some people think they may be chocoholics. Another factor is hormones.
Some women particularly crave chocolate around the time of their menstrual period.
It may be related to the increase in estrogen and progesterone. A magnesium deficiency can also play a part. Chocolate contains magnesium and some people may crave it because their magnesium levels are low. The other factor is taste. No one can argue that chocolate just tastes great.