I wish it were otherwise, but nearly all of us either have or have seen someone in our lives struggle with addiction--we may have even struggled with it ourselves.
Of course, there's a lot of discussion around addiction and many experts weighing in, most of whom have something helpful to say. But if you've ever had an addict or addiction in your life, you know nothing is simple. There's no clear "a-ha" explanation or solution. The slog through it is inevitably a complex one, even in the best-case scenarios when there's a happy ending to the tale.
Dr. Gabor Mate wrote one of the most incredible books I've read on this subject: "In the Realm of Hungry Ghosts." It's written with human empathy, spiritual consciousness, and authority. There are many firsthand anecdotes and lessons he's learned from years working with adult addicts in a low-income housing project.
This article overviews some compelling takeawayas from Mate's writings ... Pick up his book if you get the chance to as well. Anyone who's been touched firsthand or second-hand by addiction will find it moving, inspiring, and clarifying.
Read the overview here: http://upliftconnect.com/why-were-a-culture-of-addicts/
And find Mate's book on Amazon here: https://www.amazon.com/Realm-Hungry-Ghosts-Encounters-Addiction/dp/155643880X