I am not so sure that they do have a choice. Their reality is distorted and they have a vital missing chip. They are in a sad lonely place, and the occasional glimpse of the real and fullfilling life that humans can and so aspire to, is something they seem unable to reach out and grab.
I see it with my daughter. She has choices every day, and continually takes the choice that works against her own happiness. She does not have a partner/husband/S.O. so it is a different dynamic that I see with her than I had with my H. My H was essentially unhappy, mean spirited and negative, despite his cheery demeanour. My daughter is none of those things, but she is heading that way. By turning on those who care for her, by fighting against any advice, or any information about the needs or wants or interests of others, by having done it all her life, and now as she approaches adulthood, it is very hard to give of yourself to her, to help her or support her, because it gets thrown back in your face, and such is the downward, vicious circle of HER life. And it is her life, and it is soo o sad