This guy doesn't fully understand what he is talking about.

First things first:

"Imagine if you and I and the next twenty people to pass us on the street take a really potent drug for twenty days. There are strong chemical hooks in these drugs, so if we stopped on day twenty-one, our bodies would need the chemical. We would have a ferocious craving. We would be addicted. That's what addiction means."

Wow. Just wow. An addiction is (in part) when someone can't overcome the craving. Just because we crave something, doesn't mean we are addicted to it.

"this discovery is a profound challenge to the...view that addiction is a disease taking place in a chemically hijacked brain."

Not 100% true but not 100% false. Most of the issues with addiction are neurochemical, specifically with dopamine. Dopamine is a hormone and neurotransmitter that is has a lot to do with our reward system. Whatever we enjoy, food, sex, reading, watching movies, etc. is strongly related to dopamine. We do something enjoyable, dopamine is released and we become happy. Drugs can do the same thing, they cause dopamine to be released, which makes us associate them with pleasure. If we take away something such as a powerful drug that gives us a huge increase in dopamine, we start to want it, to crave it. Some people can ignore the craving and some can't. Those that can't will develop and addiction without the proper help.

However is true that a component of addiction is the environment.

"Gamblers' Anonymous meeting in Las Vegas (with the permission of everyone present, who knew I was there to observe) and they were as plainly addicted as the cocaine and heroin addicts I have known in my life. Yet there are no chemical hooks."

Again false. Gambling addiction works along the lines of any other addiction from a neurochemical point of view. It provides the same release of dopamine as an addictive substance would give and people who have a gambling addiction are those who struggle to deal with the craving.

As for the rest of the article, it mostly makes sense. Take away the environment that causes the issue and get people help, the issues they have should go away. I said 'should' because there are some instances where unfortunately it doesn't work. Also for his regard to the heroin, the author is British and they uses (although I think they are slowly phasing that out) heroin as a pain medication. Most places use morphine, oxycontin, etc.