I don't believe that nutritional deficiencies are the reason people seek alcohol.

However, I do believe there is a correlation between someone who seeks sugar, and drugs or alcohol. It is known that manic depressive people often crave sugar. It may be a matter of some people needing to seek the stimulation of substances to try and balance out their own imbalances. Self-medication via diet and/or drugs. It may be useful for affected people to understand why they are craving these things, however, I don't know that it will allow them to quit needing them. The chemical imbalance that gave them the craving, is still present.

If sugar/carbs led to the chemical imbalance in the first place, wouldn't we all be alcoholics or drug abusers?