Since 1920s Government’s have tried to effect the supply of certain misused drugs through making them illicit. So they impose penalties and criminal records for possession and supply.
Drugs are categorised into 3 classes: A,B and C. The highest category generally applies to the more dangerous drugs such as heroin or cocaine, the drugs where it is easier to develop dependence or overdose on.
Drugs can move between classes (cannabis has moved down to C then back to B) but these changes cannot be shown to make a big difference to people’s choices and behaviour.
But taking illicit drugs means added risk: taking a chance on the substance itself and not getting caught which can affect your employment and travel opportunities.