The opiate epidemic was caused by an extremely complicated web of independent factors that created a perfect storm, and in “Dreamland,” Quinones delves deep and creates a compelling case for each one of those factors, and for how they worked in concert. From changing attitudes about pain management in the medical community, to new methods of marketing by drug companies, the innovative modes of heroin distribution arising in the 1980s, and the unexpected incentives created by SSI and Medicaid, Quinones pieces together how each group acted with rational intent — whether to help patients or help themselves — in a way that didn’t need to anticipate how those factors would work in concert. It’s a fascinating read that focuses on first-person stories and does a great job of unraveling the complicated threads of causation.