We are talking about the actions of people who regularly use illegal drugs or regularly abuse legal drugs - INCLUDING ALCOHOL.
For the sake of clarity, we'll refer to both of these as drug abuse.
While this includes the use of illegal substances like heroin, cannabis, cocaine, ecstasy and suchlike, it's very important to remember that it also includes the abuse of prescription drugs like tranquillisers, sleeping pills etc. - and alcohol.
In the next few pages we'll take a look at drug abuse and drug dependence.
Drug abuse means the voluntary abuse of drugs - i.e. where people choose to do so.
Dependence is a bit further down the line and involves compulsive abuse of drugs - i.e. where people are driven to abuse them by a powerful internal compulsion.
Each section is very short. Click on the page numbers above to move through.