I offer this from personal experience. When someone has a mental illness they hurt in a way that nobody else can really understand in part because for each person it is different. It will change the way that you see things and more importantly how you feel and feel about things. This is a pain that eventually you will do anything to stop and for many, they take the final solution.
Along that road, it is easy to step off and onto all sorts of side roads seeking relief or help. I gather that you are religious. Were you and your brother raised in religion or did you go there later in life? What happens so often for someone that has faith when mental illness begins to take over their life they turn to their faith and ask, pray, and beg for help. When that help doesn't come they begin to feel a deep resentment that their God has abandoned them. It is so easy when you are this far down to grab anything that gives you any sort of relief. Drugs and alcohol are common and as bad as they are they are by far not the worst things that you can turn to.
In the end, depression is when you stop liking yourself and you are angry. You turn this anger in and it eats you ALIVE. When you turn to the dark you learn to convert this self-directed anger outward. Hate and anger hurt less than depression. It is so easy to hurt others and in that release some of the pain that is within. You stop hating yourself and start hating God and then other people that because of their success always made you feel like a failure or in any way less. The Dark side not only allows this it encourages it and it makes you feel powerful and better about yourself.
Some can be saved if the right person reaches them at the right time but many just sink deeper and deeper. I can tell you this. There is nothing that you can do to help him if he is already focusing on you. When you even try he is going to see it as you, the bigshot good son, are as usual just trying to making him look bad.
All you can do for him is to pray for him and try to avoid him. YOU can do NOTHING right for him. I will also add that you must protect yourself and those that you love and are responsible for. Stay away and keep your kids and wife if you are married away from him. You can love him, you can forgive him for the evil and mean things that he does to you but you can't be around him or let him control or destroy your peace. Evil has no good side.
If he can be saved there are two things that will have to occur. He must still WANT to be helped and then he will need the right person to be the one to hold out their hand to him. It CAN happen!
