Recursion

Blake Crouch is the prodigious author of speculative fiction books and this is the 2nd book of his I have read (see my post on Dark Matter). He offers up another example of a mind bending proposition, in this case, what if memory creates reality. And what if you could change people's memories or let them go back into a remembered event and start life over from that point. There would be a new timeline to accompany that life. Only it turns out that the previous timeline/ set of memories, would also still be present. It might be enough to make people crazy. And that is what happens. As more and more people are affected by "False Memory Syndrome" mass insanity follows.
It started out with the best of intentions by scientist Helena Smith--what's that saying about paving the road to hell--as she tries to find a way to map and recreate memories  to alleviate the losses associated with Alzheimer's Disease. But this research, prompted by her mother's own descent into disconnection through forgetting, gets hijacked by a lab tech, Marcus Slade, who first uses the technology to make a personal fortune, and then to sell the technology to those who regret the roads not taken. Unfortunately, the ultimate outcome is that the plans for building the "memory chair"--which basically allows the altering of reality--is hacked from Slade's lab and people begin to use it for bad purposes and nuclear war on a massive scale ensues. So the creative genius behind the chair, Helena, goes back and lives life over, time and time and time again, trying to make things turn out differently.
It was compelling but also somewhat mentally exhausting to read this and to stretch my mind around how this can happen. Recommended for hard core sci-fi readers only.
Laudatory reviews on NPR, from the New York Times, the Washington Independent Review of Books, and from Kirkus which accurately calls this book "An exciting, thought-provoking mind-bender."