What is a spouse/significant other supposed to do when the other half decides to let it all hang out or give up on life?

What is a spouse/significant other supposed to do when the other half decides to let it all hang out or give up on life?  What is a spouse supposed to do when their significant other decides to ignore their health and basically has given up on life and is slowly dying?  You’re active, full of life and energy, while your spouse, because of an event, becomes an Oompa Loompa  from Charlie and the Chocolate Factory or Jabba the Hut from Star Wars.  I have a family member in the aforementioned predicament.  She is at a loss of what to do.  Part of her is concerned about her husband and part of her is frustrated, and lastly, she’s resentful!  She feels the latter because her husband is making a choice about his health and that he is being selfish.  His reply is that it is only hurting him.  However, anyone who has suffered from a family member with Alcoholism or Drug Abuse is well aware that those issues affect the entire family!  What is the best way to approach this situation?  To be frank with you, I am not totally sure.  What I did share with her is to first to be supportive and empathetic!  Yet, this situation the needs to be followed by some tough love.  If any of you who have a similar situation, I would love to hear your stories and recommendations.    Feedback is encouraged in order for me to serve you better!   Robert Ealy, MD