This is the Guardian.

When actor Matthew Perry's death was announced a little over a week ago,

social media was immediately flooded with fans sharing their favorite clips from friends.

Anybody know a good tailor?

You need some clothes altered?

No, no, I'm just looking for a man to draw on me with Chuck.

But amongst them there was another one that went viral. It was the actor appearing on the British Current Affairs

show Newsnight in 2013. I'm a drug addict. I'm a person that if I have a drink I can't stop and so it would be following your

ideology that I'm choosing to do that that I'm choosing... That's exactly my not my

ideology it is my belief yes you do choose.

Having fought his own addictions for many years, he became an advocate for a rehab-based approach to drug crime

and found himself debating the science of addiction with the journalist Peter Hitchins.

People have problems with drugs and drink. People like taking them and they don't want to stop taking them.

But it doesn't mean they have a disease that needs to be treated.

So the American Medical Association is wrong in your opinion?

If the American Association says it's a disease, yes, of course they're wrong.

Ten years on, our understanding of the complex causes and impacts of drug and alcohol dependency

have advanced considerably.

So today, we're exploring the latest science of addiction with one of the leading researchers in the field.

I'm the Guardian Science Editor Ian's sample and this is Science Weekly.

I was intrigued by how was it possible that certain drugs can actually lead a person to actually completely disrupt their lives.

That explanation given by many that this is just a choice behavior made absolutely no sense. Dr. Nora Volkoff is the director of the US National Institute on Drug Abuse,

...