How can you help someone who is struggling with substance abuse?
First they most likely require a medical detox, From there they need to explore treatment options with a counselor or social worker
THEY MUST ADMIT FIRST & FOREMOST. Unless they acknowledge their situation, & WANT HELP, PRAYING IS THE NUMBER OND THING YOU CAN DO IN ANY SITUATION FOR ANYONE. However, & regardless, if you feel that they are harmful to themselves or anyone else, you can get a Coroner to have them committed to the necessary surroundings.
You can't, until they hit rock bottom and are willing to admit they have a problem there is nothing you can do for them. Love can not help an addict, and it takes an addict to help an addict. Find out where the NA meetings are so when they are ready and do actually want help, you can get them to a meeting ASAP. What you can do for YOU is go to Nar Anon meetings, it is for family and friends of addicts, it will help you to be able to deal with the addict.http://www.nar-anon.org/ ( clean since 6-19-2008 )
Trek is pretty right on with her answer, and same with the others. Here is another link you may find helpful.http://www.helpguide.org/articles/addiction/drug-abuse-and-addiction.htm
You can't, only a person who has a problem can deal with it. If they haven't asked you for help, I think the best thing you can do is first talk to them. See if they're even willing to quit. If they are, then watch them, help them through withdraw, maybe put them in rehab. If they don't want to change, you can turn them in for substance abuse. It seems harsh, but really, they're getting watch 24/7, they will be taken care of, some will put them in rehab if they need it and ask. It keeps them off of the drugs and they are watched over. Sometimes it's all that you can do