What is the Definition of Drug & Alcohol Abuse?

What is the definition of drug and alcohol abuse?
Any level of alcohol or drug use that results in physical or social or any other form of damage. There is no clear dividing line between ‘misuse’ and ‘abuse’ other than in the minds of those who want to rationalise a particular level of alcohol consumption. Anything that causes damage is obviously ‘too much’ and that’s that.
Medical and political pundits like to make distinctions between use, misuse, abuse and whatever. But these are merely theoretical concepts. They have no relevance in clinical practice. Doctors can tell alcoholics whatever they choose but they won’t be heard. The alcoholics listen only to their internal voices that rationalise and justify their drinking behaviour and explain away its consequences.
The only reason for continuing to use a damaging substance is that it provides the user with a perceived benefit. If the alternative to alcohol is suicide, the sensible choice is to drink alcohol rather than cyanide.
Families and doctors find this difficult because they use ‘normal’ rather than ‘alcoholic’ reasoning. Alcoholics drink to make themselves feel better. When the alcoholism really takes hold, they drink because they drink. The first drink triggers the craving for the next. That’s abuse in anyone’s language.