The likelihood that someone will become addicted to a substance is actually much more affected by the route of administration than the substance itself. Addiction primarily happens as a result of people linking an action (e.g. taking a drug) with a reward, and the less time there is in between taking the drug and it taking effect, the more powerful that connection.

In terms of addictive potential for any given drug:

smoking > injecting > snorting > eating > topical

If you were to actually compare drinking crack with drinking coffee, the addictiveness of both would be identical.

Route of administration changes how quickly, how hard and in what way drugs hit you. For example, someone could rub some coke on their gums and have a numb mouth and be slightly more alert, or snort the same amount and get a rush.

I think you're mistaken. While the first part is certainly true - I remain doubtful about the implication for addictive potential of a drug - the second part is a rather bad example:

Both in your nose and in your mouth the drug is absorbed into the bloodstream via a mucous membrane. The reason you don't see a lot of people putting large doses of cocaine on their gums is largely practical... same thing for mdma for example, just the other way around.

/edit The coke-numbs-your-gums part is supposed to be a test for the quality of the product, easily faked though.

You're focussing on physical addiction. A drug hitting you nearly instantly (IV use) vs over a period of time is definitely more psychologically addictive. There's really no argument there..

>Both in your nose and in your mouth the drug is absorbed into the bloodstream via a mucous membrane. The reason you don't see a lot of people putting large doses of cocaine on their gums is largely practical... same thing for mdma for example, just the other way around.

It's more practical to put it in your gums though - you don't need to lay it out, crush it up, line it up into lines, find/roll a tube etc. You just stick your finger into the packet and rub it on your gums. Do a little research - snorting affects you in a more intense way.

> /edit The coke-numbs-your-gums part is supposed to be a test for the quality of the product, easily faked though.

Cocaine was used by dentists to numb gums. It acts as an anaesthetic. Drug dealers play on this and add numbing agents to other drugs and pass it off as coke.

I find myself wondering how someone would go directly form clean to "lets stick this needled in my arm". Likely by that time the person is already craving it after having had it several times via other means.