So apparently, drugs don't cause addiction, poor living conditions makes people seek relief however they can. Often, they can buy drugs, and consume them.

The main argument proposed by the article's author is that cocaine and heroin are themselves not inherently addictive. Because these drugs are perceived to be the most addictive, he extrapolates his hypothesis to all drugs.

Claim A: All or most people who use heroin or cocaine beyond a certain minimum amount become addicted. Claim B: No matter what proportion of the users of heroin and cocaine become addicted, their addiction is caused by exposure to the drug.

Claim A he refutes with a number of seemingly good studies, while Claim B proves itself hard to deny out-right, and still hard to endorse.

The article is an interesting read, if not particularly enlightening, it at least provides some food for thought. The Rat Park experiments are particularly interesting. Would you use less if you had more?