Mental illness is defined in terms of mental processes that interfere with your life. Suicide is the definition of a mental process that interferes with success

Mental illness is defined in terms of mental processes that interfere with your life. Suicide is the definition of a mental process that interferes with successfully living your life. That being said, I agree with your point. One should be the master of their own existence from a certain viewpoint, but we aren't. Humans are social creatures and define our lives in terms of those relationships. Even if you are a solitary hermit, you define your life in relation to the people that aren't around. I'm not trying to be clever there. I can see where suicide can be considered the most rational response given the right social or societal context. See any number of ritual suicide practices in human cultures. Again, even the physician assisted suicide that we debate so often make sense in the context of maintaining some notion of dignity in one's familial or social group. When you add human suffering to that situation it becomes a moral imperative, I think. That's just me though.