Question: How addictive are drugs?

Lori-An Etherington answered on 14 Jun 2010:

The answer to this question depends on the drug. There are only some drugs which cause addiction at all and many of these are not used medically (such as heroin, nicotine, cocaine and alcohol). When someone is addicted to a drug they are what is called ‘dependent’ on that drug. There are two types of dependence, psycological (where they want to feel better by taking the drug) and physical (where they have symptoms like shaking, increased heart rate and sweating when they have not taken the drug). Nearly every drug which causes addiction, causes an increase in a brain chemical called dopamine in a specific pathway of the brain called the mesolimbic system and it is this which is believed to be cause of dependence.