To dream of the drug heroin represents obsession or euphoria with believing how wonderfully perfect something is. Believing that something perfect is so good it will never go away.
Negatively, heroin represents ignorance or stupidity about thinking that there can never be anything wrong or dangerous with something perfect you are interested in. An inability to be objective or critical about negative aspects of a perfect situation. Thinking "the bill" won't come or that there is no "fine print." Naively believing that good times are forever. Pleasure or optimism overrides your good judgement. Annoying people you know with your personal stories about how perfect your life is.
Emotional addiction to a perfect experience. Risking serious losses because you can't separate your need for experiencing perfection from objective reality. Obsessive or compulsive behavior with something you like a lot. Obsessive behavior that makes other people want to stop talking to you or know you anymore.
Heroin addiction in a dream may reflect how you are continually screwing yourself over being too optimistic or to obsessed with something you feel is perfect. It may also reflect hurting yourself desiring someone exceptionally beautiful who keeps embarrassing you. Perfection that you can't resist or once experienced is dangerously difficult to cut off.
Example: A woman dreamed of being a heroin addict. In waking life she was accused by her boyfriend of being obsessed with talking about her new job aboard.
*Please See Opium