3.5 stars. I think I would have enjoyed this audiobook more with a different narrator, or if I had read the book rather than listened to it. The narrator sounded like a computer to me, no personality or inflections in his voice, just a monotone. So the book lost half a star for that alone, as it was distracting.
Other than that, I enjoyed it. There was nothing terribly new about the first part on addictions. Yes, we get "rewards" for our addictions; that is why they are so hard to break. As a former psychology major, I am well familiar with BF Skinner and operant conditioning. Brewer spends a lot of time on Smartphone and Facebook addiction, I guess to keep things current, along with other more typical physical and psychological addictions (cigarettes, etc.) The chapter on addiction to overthinking was interesting to me, as I certainly suffer from this tendency, though I am not convinced it is really an addiction as much as a personality trait.
As an avid cyclist, I particularly enjoyed the chapter about Lance Armstrong, whom Brewer admits to idolizing and then, later, being unable to believe the doping charges being leveled against his hero until the evidence was overwhelming. I could have written that section as I felt the same. I also appreciated Brewer's description of the "flow" that he experienced while riding his mountain bike, as I have felt the same. Mountain biking is the ultimate in mindfulness as you really do have to remain focused on the challenges coming at you at that moment...no zoning out!
The latter part of the book focused on mindfulness and meditation as a means to overcome our addictions. I have been doing much reading on mindfulness and meditation lately but had not considered this connection. There is quite a bit of science behind this, and Brewer's scientific knowledge is impressive. In the Epilogue he promotes his mindfulness app, which I haven't checked out yet, but it does sound like it could be helpful. I didn't find the promotion to be intrusive, since it was only offered up at the end of the text and not advertised throughout.