Basically yes, but to seemingly uncontrollable extremes. Much of it is genetic & it can explicitly show up in brain scans. I've spent much of my adult life hating myself & wondering why I couldn't control it. It is a mental illness which is not seen, as is a physical illness, but it's still real. Many people scoff at that, & if I didn't have it I probably would doubt it also. Many many people with it die young.