Before you get close to your loved one, take the time to learn about addiction, detoxification, withdrawal, and the various treatment options. The more you know, the better you can approach the situation calmly and confidently. Understanding what the person is going through, at least academically, will help you to speak with knowledge when the time comes to discuss the problem. It is a diagnosable disease with many causes, some of which may be genetic.
People who struggle with addiction are ultimately responsible for their behavior, but they didn't choose addiction. Similarly, drug addiction is not a reflection of morality or character. Naturally, there are a lot of addictive substances; drugs and alcohol are the most common. While a heroin addict and an alcoholic undoubtedly have different experiences with addiction, both suffer from an illness and have lost control of their lives because of addiction.
While this is inevitably true in many ways, you shouldn't approach someone you're trying to help without first trying to familiarize yourself with their addiction disorder. If the addict refuses to get help once again, don't try to give them money or let them stay at home. The addict's brain has been hijacked by drugs and leaves him powerless to see himself and make truly rational decisions. If they seem worried or have doubts, the addict will feel that this is not a good time to leave and may postpone seeking help.
Formal interventions pay special attention to both timing and dosage, and if you find that you cannot help the addict in their life on their own, it may be a good idea to organize an intervention with a professional interventionist. If you want to know how to help a drug addict who doesn't want help, you must first understand what they're struggling with. It's not enough to understand what addiction is, in order to really reach out and help someone, you must also do everything possible to imagine how the person might feel. Even before attempting to approach an addict regarding their substance abuse or related behaviors, one must have a basic understanding of addiction.
It's hard to watch a loved one refuse to get help over and over again, but many addicts need this time to realize they have a problem. Since you're about to research addiction treatment options, you've likely noticed worrying signs of addiction in a family member. It's OK to help the addict look for work or choose a treatment center, but you should establish clear boundaries around behaviors they consider unacceptable. An intervention is a meeting where several loved ones, colleagues, or family members get together to encourage an addict to seek help.
You can support them by maintaining patience, stopping doing so and giving the addict some space if they need it, but most importantly, you should never stop helping them get clean. When you're trying to help someone who's addicted to drugs or alcohol, there are things you can't do.