Addiction swallows lives whole, and not only with overdose, illness and concentric cycles of rehab and relapse. A less onerous but still tenacious kind of post-traumatic stress disorder may develop as well, with recovered addicts and their families compulsively reliving the past in private — or, like David Sheff and his son Nic, in public.

In the last five years the two have written a small library of memoirs centered on Nic’s battle with substance use, with two by Nic (now 31, and sober) and the 2008 best seller by his father, “Beautiful Boy.”

Now comes “Clean,” less memoir than guide for those just entering the terrain Mr. Sheff knows so well. If the book represents a certain redundancy of subject, its likely audience — those who must watch as friends and family spiral away — cannot hear too many sympathetic reiterations of the same truths.

In “Clean,” Mr. Sheff changes perspective, writing as advocate and journalist rather than distraught father. Still, his story line recreates that of “Beautiful Boy,” tracing the trajectory of addiction from cradle to rehab and beyond with the same question in mind: How does a promising cleareyed kid from a good family wind up in an inconceivable sea of trouble?