Viktor Frankl was a famous psychiatrist who also endured concentration camps. First part of this book is about his experiences there. Second part talks about logotherapy. Where Freud saw desires, Adler power, Frankl sees "meaning" as the main motivation power for a man.
"The privilege of actually smoking cigarettes was reserved for the Capo, who had his assured quota of weekly coupons; or possibly for a prisoner who worked as a foreman in a warehouse or workshop and received a few cigarettes in exchange for doing dangerous jobs. The only exceptions to this were those who had lost the will to live and wanted to 'enjoy' their last days. Thus, when we saw a comrade smoking his own cigarettes, we knew he had given up faith in his strength to carry on, and, once lost, the will to live seldom returned."