It's a choice, just like suicide is a choice, and believing in delusions is a choice. But it's a choice made from a mentally ill place of mind. Is it a choice people have control over? Sometimes not. Sometimes I choose to self-injure rather than kill myself, or lose it with my kids. Sometimes the choice is the lesser of two evils. And sometimes, for me, it's the 'easy' way out, because I've become accustomed to it as a coping mechanism.