Some persons may use chocolate as a form of self-medication to compensate for insufficient food intake or specific nutrient deficiencies. Scientists have speculated that chocolate consumption may be motivated in some part by magnesium deficiency . Magnesium deficiency results in selective depletion of CNS levels of dopamine, a neurotransmitter that transmits signals of euphoria and satisfaction and that may be the master molecule of addiction. Elevated CNS levels of serotonin unopposed by dopamine are believed to play a primary role in several PMS symptoms. Therefore, it is possible that stress-induced magnesium deficiency contributes to the increase in chocolate cravings associated with PMS. Nuts contain comparable amounts of this nutrient, however, and should be craved in a similar way.