Mental burden can be productive (if you’re learning or problem solving) or unproductive, taxing your working memory and stifling innovation. Unproductive mental burden usually comes from external sources—threats or obligations you have to worry about—but for people with mental illness, some of the mental burden comes from within.
Consider how much mental energy something like an anxiety disorder or obsessive compulsive disorder uses up. Add stigma, which occurs partly because other people can’t see an external reason for your mental distress, and your mental burden goes up even more.
Mental illness has, until recently, not received the same amount of attention or research funding as physical illnesses. In many parts of the world, treating mental illness is seen as a luxury. But a mental burden model of suffering puts mental and physical illnesses on a level playing field, especially if we start thinking of pain and discomfort as sources of mental burden, not as suffering in themselves.