If someone was unknowingly injected with heroin, would they still get addicted and how would their addiction manifest itself?

This may seem like a dumb question but I often wonder about how much of an addiction is psychological. They say that individuals get addicted and become dependent on heroin after the first use. So, if someone was injected without knowing it (don't ask me how) and had no idea that they had heroin in their system, would they still experience feelings of dependence, and if so, how would this addiction manifest itself?