I mean because of DP I had to drop out of high school and spent the majority of the past few years in and out of various psychiatrists barely leaving my house except for a few attempts at working.. so yeah, I consider it a mental illness. I've known people over the years for have killed themselves over this. Its not the the properly working defense mechanism of dissociation working, this is an abnormality.. a dysfunction.I don't personally view DP as a mental illness. I sort of see it as the opposite. Our brains our actually doing too good of a job. It's trying to protect us from emotions so we can get out the scary situation. Problem is there is no scary situation so it just keeps searching for one.