The overriding idea in any piece of fiction is known as its theme. It tells us what the piece of literature is about, what happens, what ideas the writer wanted to convey, etc.
Answer: The people that create these drugs could possibly know if opioids are addictive and I think they do. I also feel like doctors know people's value of things sometimes and they would possibly want to ruin that for those people because they just want their paycheck. The people that make these drugs make these because they also know if someone is in a hospital and they are there for an important reason those doctors are going to give them drugs. Those drugs they make are dangerous and they know that. So, yes I believe they do put people on to addictions.
(I'm so so sorry if this is bad, I'm not so good at this writing thing)
Depends on the time but most colonists died off or were sick due to diseases, malnutrition, which led to starvation and even contamination. Dirty water and many ate the dead and took the chance to live from it or not due to rotting flesh and pests.