It's sad watching someone go. Even sadder to see them seemingly take their own life with alcohol or drugs of even cigarets. There are so many temptations to use external devices to cope and withdraw from the terrors of reality. It's too bad these same things also simultaneously destroy us. What's even more insidious is how they slowly creep in and blend with our lives and finally attach to our identity. We don't have to identify the addict with their addiction. No matter how angry we are and how much they disappoint us we can't go on punishing them. They got duped some time ago and presently the addiction will continue to hand out the punishment.
Maybe they hate something or everything about life, are depressed, or see themselves as a martyr, a victim or all of the above. Whatever it is, it's a thick onion to peel and few of us have the time, energy or know how to get through to them on a level that will affect change. Can you imagine how someone must think who continually poisons themselves every day? It's quite extreme and to the more rational downright scary. What scares us most is how we can subtly see ourselves reflected in them.
What if I was like that? Could I go that far out of control? What am I doing that's destructive to others? The mirror reflected back shows us some intense truths about our own existence. There can and should be so much joy in the world. As a matter of fact there always is. There has to be to counter act the darkness. But if we look into the darkness for too long or too often we start to miss the light. We start to believe there is only darkness. This is where we can become lost to it and consumed by it. And this may be far worse than any addiction of affliction.
You must develop a process for renewing yourself spiritually. The more darkness you confront the more you need a process to practice. I don't care what it is but try everything, mantras, meditation, exercise, yoga, journaling, walking, hiking, dancing, laughing, etcetera until you find something that works for you. That way when darkness clouds your world you are ready. You may not be able to destroy all of it or make it disappear. However your corner of the world will be a the least a little brighter, more pleasant and more livable. You'll stand up taller in the face of this evil and rest in the confidence that everything truly is ok.