Drugs and their abuse is a serious issue that predominantly the youth all around the world face. More often this problem begins when it's forcefully induced onto someone or pehaps peer pressure plays a very negative role. The persistence of such a problem is also because many in the society have a very prejudiced opinion about drug addicts. This sometimes creates a stigma around the person and further isolates him/her from potential help. So i for one believe in having an interpersonal chat with such a person. Feel free to initiate a conversation should you feel like you need to talk and take positive measures.