[1] The release of the book coincided with the 100th anniversary of the Harrison Narcotics Tax Act in the United States, which was the world's first drug control legislation when it passed in December 1914.

[2] In the introduction to the book, Hari writes that one of his first memories was of trying and failing to wake up a relative from a "drugged slump", and that he has always felt "oddly drawn to addicts and recovering addicts—they feel like my tribe, my group, my people".

He also discusses his history of abusing anti-narcolepsy medication, a class of prescription drugs sometimes taken by people without the disease in order to stay alert.

"[3] Hari writes that he spent the next three years in search of answers, traveling across nine countries (United States, Canada, Great Britain, Mexico, Portugal, Switzerland, Sweden, Uruguay and Vietnam).

[24] Ed Vulliamy called the book a "righteous assault" and a "long-awaited history" on the war on drugs, "which imprisons millions and persecutes more".

He noted the author's 2011 scandal, writing that a "shamed" Hari left to dedicate himself to documenting the war on drugs and that Chasing the Scream "is the prodigal fruit of that work, and with it redemption, if that was needed.

He wrote that although the work is a "powerful contribution to an urgent debate" on drug policy, Hari employs a "gauche journalistic equivalent of the narrative voice found in Mills & Boon novels".

[20] Harris also admitted Hari's past record presents a challenge to reviewers, and made him more skeptical over things such as the DuPont interview, writing, "though it might be nice to set aside the events of 2011 and allow him a fresh start, his misdemeanours inevitably colour your experience of the book".

[20] Hugo Rifkind wrote in his review for The Times that it is "tempting, albeit petty, to read Chasing the Scream less as a book and more as an act of rehabilitation".

[27] David Nutt, an English psychiatrist and neuropsychopharmacologist specialising in drug research, wrote a positive review of Chasing the Scream for The Evening Standard.

"[28] Seth Mnookin, professor of science writing at MIT, wrote in his New York Times review that Hari is "in over his head" when writing about the current science of addiction: "[H]is misunderstanding of some of the basic principles of scientific research — that anecdotes are not data; that a conclusion is not a fact — transforms what had been an affecting jeremiad into a partisan polemic".