At the same time, I don't think he is ill. While I don't doubt that he is suffering, I don't think it it is helpful to class his suffering as an illness. I don't think anyone argues that his symptoms are caused by an infection or a defect in an organ, so his disorder lacks the physical basis for a typical illness. At the same time, he has symptoms. And therapy, and possibly drugs, make him feel subjectively better. He chooses to engage in a regime of therapy which (presumably) has self reported benefits.
But I don't think it is helpful to think of his plight like we think of malaria or polio or heart disease. When we talk about 'emotional disorders', we implicitly take on an enormous amount of cultural context as well as normative judgements about how someone 'should' feel. And the danger is that one will come to believe that an unpleasant mental state in an otherwise healthy brain is something to be cured through the application of science.
That being said, I agree with the main point -- that there is no shame in his mental state. I suppose my point is that it is not necessary (and should not be necessary) to reclassify what a disease is in order for a class of people to maintain their dignity. And above all, I wish this man well and by no means mean to diminish his pain, or the courage it took to write this.