I'm not a data scientist nor working in health care, but my personal opinion leans towards drug abuse being more related/linked to a person's personal experiences, upbringing, and social and economic conditions rather than primarily being linked to where they live. Both rich and poor statistically are represented in terms of drug abuse, the consequences for drug abuse are often more severe for abuse if one is on the less affluent side though (enforcement-wise and health-wise in a historical sense).