Does going through a drug intervention really help?

My friend constantly denies the fact that he is actually a drug addict. Each time we put up the issue, he shrugs and tells us that we upset him. But in fact, it us who he upsets. He’s bad-mouthing and ill-mannered, very far from the person we have grown to love. We want an end to this. We want him to accept his condition and get free from it eventually. Another friend suggested a drug intervention, but none of us is entirely familiar with it. The only thing we know is that it can help my friend realize his addiction and eventually agree to undergo a drug treatment program. Is that it?