alcohol
... Craving has gradually evolved into an overpowering obsession--the alcoholic craves alcohol because it is the most effective remedy for the pain he feels when he stops drinking. ... It seems that every body craves something once in their lifetime, but the notion of how alcoholics are given an irresistible urge to drink points how alcohol weakens a person’s mind and capacity to think about what choices can be made to subdue this craving. ... For instance, they say that the cells in the body have a tolerance to alcohol that tells the body it needs alcohol in order to pacify the addiction.